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postgresql/src/backend/parser/analyze.c

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/*-------------------------------------------------------------------------
*
* analyze.c
* transform the parse tree into a query tree
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.207 2001/11/02 20:23:02 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/heapam.h"
#include "catalog/catname.h"
#include "catalog/heap.h"
#include "catalog/pg_index.h"
#include "catalog/pg_type.h"
#include "nodes/makefuncs.h"
#include "parser/analyze.h"
#include "parser/parse.h"
#include "parser/parsetree.h"
#include "parser/parse_agg.h"
#include "parser/parse_clause.h"
#include "parser/parse_coerce.h"
#include "parser/parse_expr.h"
#include "parser/parse_oper.h"
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
#include "parser/parse_expr.h"
#include "rewrite/rewriteManip.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/numeric.h"
#include "utils/relcache.h"
#include "utils/syscache.h"
#include "utils/temprel.h"
#ifdef MULTIBYTE
#include "mb/pg_wchar.h"
#endif
/* State shared by transformCreateStmt and its subroutines */
typedef struct
{
const char *stmtType; /* "CREATE TABLE" or "ALTER TABLE" */
char *relname; /* name of relation */
List *inhRelnames; /* names of relations to inherit from */
bool istemp; /* is it to be a temp relation? */
bool hasoids; /* does relation have an OID column? */
Oid relOid; /* OID of table, if ALTER TABLE case */
List *columns; /* ColumnDef items */
List *ckconstraints; /* CHECK constraints */
List *fkconstraints; /* FOREIGN KEY constraints */
List *ixconstraints; /* index-creating constraints */
List *blist; /* "before list" of things to do before
* creating the table */
List *alist; /* "after list" of things to do after
* creating the table */
IndexStmt *pkey; /* PRIMARY KEY index, if any */
} CreateStmtContext;
static Query *transformStmt(ParseState *pstate, Node *stmt);
static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt);
static Query *transformIndexStmt(ParseState *pstate, IndexStmt *stmt);
static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt);
static Query *transformSelectStmt(ParseState *pstate, SelectStmt *stmt);
static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt);
static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt);
static Query *transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt);
static void transformColumnDefinition(ParseState *pstate,
CreateStmtContext *cxt,
ColumnDef *column);
static void transformTableConstraint(ParseState *pstate,
CreateStmtContext *cxt,
Constraint *constraint);
static void transformIndexConstraints(ParseState *pstate,
CreateStmtContext *cxt);
static void transformFKConstraints(ParseState *pstate,
CreateStmtContext *cxt);
static Node *transformTypeRefs(ParseState *pstate, Node *stmt);
static void transformTypeRefsList(ParseState *pstate, List *l);
static void transformTypeRef(ParseState *pstate, TypeName *tn);
static List *getSetColTypes(ParseState *pstate, Node *node);
static void transformForUpdate(Query *qry, List *forUpdate);
static void transformConstraintAttrs(List *constraintList);
static void transformColumnType(ParseState *pstate, ColumnDef *column);
static void transformFkeyCheckAttrs(FkConstraint *fkconstraint, Oid *pktypoid);
static void transformFkeyGetPrimaryKey(FkConstraint *fkconstraint, Oid *pktypoid);
static bool relationHasPrimaryKey(char *relname);
static Oid transformFkeyGetColType(CreateStmtContext *cxt, char *colname);
static void release_pstate_resources(ParseState *pstate);
static FromExpr *makeFromExpr(List *fromlist, Node *quals);
/* kluge to return extra info from transformCreateStmt() */
static List *extras_before;
static List *extras_after;
/*
* parse_analyze -
* analyze a raw parse tree and transform it to Query form.
*
* The result is a List of Query nodes (we need a list since some commands
* produce multiple Queries). Optimizable statements require considerable
* transformation, while many utility-type statements are simply hung off
* a dummy CMD_UTILITY Query node.
*/
List *
parse_analyze(Node *parseTree, ParseState *parentParseState)
{
List *result = NIL;
ParseState *pstate = make_parsestate(parentParseState);
Query *query;
extras_before = extras_after = NIL;
query = transformStmt(pstate, parseTree);
release_pstate_resources(pstate);
while (extras_before != NIL)
{
result = lappend(result,
transformStmt(pstate, lfirst(extras_before)));
release_pstate_resources(pstate);
extras_before = lnext(extras_before);
}
result = lappend(result, query);
while (extras_after != NIL)
{
result = lappend(result,
transformStmt(pstate, lfirst(extras_after)));
release_pstate_resources(pstate);
extras_after = lnext(extras_after);
}
pfree(pstate);
return result;
}
static void
release_pstate_resources(ParseState *pstate)
{
if (pstate->p_target_relation != NULL)
heap_close(pstate->p_target_relation, NoLock);
pstate->p_target_relation = NULL;
pstate->p_target_rangetblentry = NULL;
}
/*
* transformStmt -
* transform a Parse tree into a Query tree.
*/
static Query *
transformStmt(ParseState *pstate, Node *parseTree)
{
Query *result = NULL;
switch (nodeTag(parseTree))
{
/*
* Non-optimizable statements
*/
case T_CreateStmt:
result = transformCreateStmt(pstate, (CreateStmt *) parseTree);
break;
case T_IndexStmt:
result = transformIndexStmt(pstate, (IndexStmt *) parseTree);
break;
case T_RuleStmt:
result = transformRuleStmt(pstate, (RuleStmt *) parseTree);
break;
case T_ViewStmt:
{
ViewStmt *n = (ViewStmt *) parseTree;
n->query = transformStmt(pstate, (Node *) n->query);
/*
* If a list of column names was given, run through and
* insert these into the actual query tree. - thomas
* 2000-03-08
*
* Outer loop is over targetlist to make it easier to skip
* junk targetlist entries.
*/
if (n->aliases != NIL)
{
List *aliaslist = n->aliases;
List *targetList;
foreach(targetList, n->query->targetList)
{
TargetEntry *te = (TargetEntry *) lfirst(targetList);
Resdom *rd;
Ident *id;
Assert(IsA(te, TargetEntry));
rd = te->resdom;
Assert(IsA(rd, Resdom));
if (rd->resjunk) /* junk columns don't get
* aliases */
continue;
id = (Ident *) lfirst(aliaslist);
Assert(IsA(id, Ident));
rd->resname = pstrdup(id->name);
aliaslist = lnext(aliaslist);
if (aliaslist == NIL)
break; /* done assigning aliases */
}
if (aliaslist != NIL)
elog(ERROR, "CREATE VIEW specifies more column names than columns");
}
result = makeNode(Query);
result->commandType = CMD_UTILITY;
result->utilityStmt = (Node *) n;
}
break;
case T_ExplainStmt:
{
ExplainStmt *n = (ExplainStmt *) parseTree;
result = makeNode(Query);
result->commandType = CMD_UTILITY;
n->query = transformStmt(pstate, (Node *) n->query);
result->utilityStmt = (Node *) parseTree;
}
break;
case T_AlterTableStmt:
result = transformAlterTableStmt(pstate, (AlterTableStmt *) parseTree);
break;
/*
* Optimizable statements
*/
case T_InsertStmt:
result = transformInsertStmt(pstate, (InsertStmt *) parseTree);
break;
case T_DeleteStmt:
result = transformDeleteStmt(pstate, (DeleteStmt *) parseTree);
break;
case T_UpdateStmt:
result = transformUpdateStmt(pstate, (UpdateStmt *) parseTree);
break;
case T_SelectStmt:
if (((SelectStmt *) parseTree)->op == SETOP_NONE)
result = transformSelectStmt(pstate,
(SelectStmt *) parseTree);
else
result = transformSetOperationStmt(pstate,
(SelectStmt *) parseTree);
break;
/*
* Convert use of %TYPE in statements where it is permitted.
*/
case T_ProcedureStmt:
case T_CommentStmt:
case T_RemoveFuncStmt:
case T_DefineStmt:
result = makeNode(Query);
result->commandType = CMD_UTILITY;
result->utilityStmt = transformTypeRefs(pstate, parseTree);
break;
default:
/*
* other statements don't require any transformation-- just
* return the original parsetree, yea!
*/
result = makeNode(Query);
result->commandType = CMD_UTILITY;
result->utilityStmt = (Node *) parseTree;
break;
}
return result;
}
/*
* transformDeleteStmt -
* transforms a Delete Statement
*/
static Query *
transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
{
Query *qry = makeNode(Query);
Node *qual;
qry->commandType = CMD_DELETE;
/* set up range table with just the result rel */
qry->resultRelation = setTargetTable(pstate, stmt->relname,
interpretInhOption(stmt->inhOpt),
true);
qry->distinctClause = NIL;
/* fix where clause */
qual = transformWhereClause(pstate, stmt->whereClause);
/* done building the range table and jointree */
qry->rtable = pstate->p_rtable;
qry->jointree = makeFromExpr(pstate->p_joinlist, qual);
qry->hasSubLinks = pstate->p_hasSubLinks;
qry->hasAggs = pstate->p_hasAggs;
if (pstate->p_hasAggs)
parseCheckAggregates(pstate, qry, qual);
return qry;
}
/*
* transformInsertStmt -
* transform an Insert Statement
*/
static Query *
transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
{
Query *qry = makeNode(Query);
List *sub_rtable;
List *sub_namespace;
List *icolumns;
List *attrnos;
List *attnos;
List *tl;
qry->commandType = CMD_INSERT;
pstate->p_is_insert = true;
/*
* If a non-nil rangetable/namespace was passed in, and we are doing
* INSERT/SELECT, arrange to pass the rangetable/namespace down to the
* SELECT. This can only happen if we are inside a CREATE RULE, and
* in that case we want the rule's OLD and NEW rtable entries to
* appear as part of the SELECT's rtable, not as outer references for
* it. (Kluge!) The SELECT's joinlist is not affected however. We
* must do this before adding the target table to the INSERT's rtable.
*/
if (stmt->selectStmt)
{
sub_rtable = pstate->p_rtable;
pstate->p_rtable = NIL;
sub_namespace = pstate->p_namespace;
pstate->p_namespace = NIL;
}
else
{
sub_rtable = NIL; /* not used, but keep compiler quiet */
sub_namespace = NIL;
}
/*
* Must get write lock on INSERT target table before scanning SELECT,
* else we will grab the wrong kind of initial lock if the target
* table is also mentioned in the SELECT part. Note that the target
* table is not added to the joinlist or namespace.
*/
qry->resultRelation = setTargetTable(pstate, stmt->relname,
false, false);
/*
* Is it INSERT ... SELECT or INSERT ... VALUES?
*/
if (stmt->selectStmt)
{
ParseState *sub_pstate = make_parsestate(pstate->parentParseState);
Query *selectQuery;
RangeTblEntry *rte;
RangeTblRef *rtr;
/*
* Process the source SELECT.
*
* It is important that this be handled just like a standalone
* SELECT; otherwise the behavior of SELECT within INSERT might be
* different from a stand-alone SELECT. (Indeed, Postgres up
* through 6.5 had bugs of just that nature...)
*/
sub_pstate->p_rtable = sub_rtable;
sub_pstate->p_namespace = sub_namespace;
selectQuery = transformStmt(sub_pstate, stmt->selectStmt);
release_pstate_resources(sub_pstate);
pfree(sub_pstate);
Assert(IsA(selectQuery, Query));
Assert(selectQuery->commandType == CMD_SELECT);
if (selectQuery->into || selectQuery->isPortal)
elog(ERROR, "INSERT ... SELECT may not specify INTO");
/*
* Make the source be a subquery in the INSERT's rangetable, and
* add it to the INSERT's joinlist.
*/
rte = addRangeTableEntryForSubquery(pstate,
selectQuery,
makeAttr("*SELECT*", NULL),
true);
rtr = makeNode(RangeTblRef);
/* assume new rte is at end */
rtr->rtindex = length(pstate->p_rtable);
Assert(rte == rt_fetch(rtr->rtindex, pstate->p_rtable));
pstate->p_joinlist = lappend(pstate->p_joinlist, rtr);
/*
* Generate a targetlist for the INSERT that selects all the
* non-resjunk columns from the subquery. (We need this to be
* separate from the subquery's tlist because we may add columns,
* insert datatype coercions, etc.)
*
* HACK: constants in the INSERT's targetlist are copied up as-is
* rather than being referenced as subquery outputs. This is
* mainly to ensure that when we try to coerce them to the target
* column's datatype, the right things happen for UNKNOWN
* constants. Otherwise this fails: INSERT INTO foo SELECT 'bar',
* ... FROM baz
*/
qry->targetList = NIL;
foreach(tl, selectQuery->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(tl);
Resdom *resnode = tle->resdom;
Node *expr;
if (resnode->resjunk)
continue;
if (tle->expr && IsA(tle->expr, Const))
expr = tle->expr;
else
expr = (Node *) makeVar(rtr->rtindex,
resnode->resno,
resnode->restype,
resnode->restypmod,
0);
resnode = copyObject(resnode);
resnode->resno = (AttrNumber) pstate->p_last_resno++;
qry->targetList = lappend(qry->targetList,
makeTargetEntry(resnode, expr));
}
}
else
{
/*
* For INSERT ... VALUES, transform the given list of values to
* form a targetlist for the INSERT.
*/
qry->targetList = transformTargetList(pstate, stmt->targetList);
}
/*
* Now we are done with SELECT-like processing, and can get on with
* transforming the target list to match the INSERT target columns.
*/
/* Prepare to assign non-conflicting resnos to resjunk attributes */
if (pstate->p_last_resno <= pstate->p_target_relation->rd_rel->relnatts)
pstate->p_last_resno = pstate->p_target_relation->rd_rel->relnatts + 1;
/* Validate stmt->cols list, or build default list if no list given */
icolumns = checkInsertTargets(pstate, stmt->cols, &attrnos);
/*
* Prepare columns for assignment to target table.
*/
attnos = attrnos;
foreach(tl, qry->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(tl);
Ident *id;
Assert(!tle->resdom->resjunk);
if (icolumns == NIL || attnos == NIL)
elog(ERROR, "INSERT has more expressions than target columns");
id = (Ident *) lfirst(icolumns);
updateTargetListEntry(pstate, tle, id->name, lfirsti(attnos),
id->indirection);
icolumns = lnext(icolumns);
attnos = lnext(attnos);
}
/*
* XXX It is possible that the targetlist has fewer entries than were in
* the columns list. We do not consider this an error. Perhaps we
* should, if the columns list was explicitly given?
*/
/* done building the range table and jointree */
qry->rtable = pstate->p_rtable;
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
qry->hasAggs = pstate->p_hasAggs;
if (pstate->p_hasAggs)
parseCheckAggregates(pstate, qry, NULL);
return qry;
}
/*
* makeObjectName()
*
* Create a name for an implicitly created index, sequence, constraint, etc.
*
* The parameters are: the original table name, the original field name, and
* a "type" string (such as "seq" or "pkey"). The field name and/or type
* can be NULL if not relevant.
*
* The result is a palloc'd string.
*
* The basic result we want is "name1_name2_type", omitting "_name2" or
* "_type" when those parameters are NULL. However, we must generate
* a name with less than NAMEDATALEN characters! So, we truncate one or
* both names if necessary to make a short-enough string. The type part
* is never truncated (so it had better be reasonably short).
*
* To reduce the probability of collisions, we might someday add more
* smarts to this routine, like including some "hash" characters computed
* from the truncated characters. Currently it seems best to keep it simple,
* so that the generated names are easily predictable by a person.
*/
char *
makeObjectName(char *name1, char *name2, char *typename)
{
char *name;
int overhead = 0; /* chars needed for type and underscores */
int availchars; /* chars available for name(s) */
int name1chars; /* chars allocated to name1 */
int name2chars; /* chars allocated to name2 */
int ndx;
name1chars = strlen(name1);
if (name2)
{
name2chars = strlen(name2);
overhead++; /* allow for separating underscore */
}
else
name2chars = 0;
if (typename)
overhead += strlen(typename) + 1;
availchars = NAMEDATALEN - 1 - overhead;
/*
* If we must truncate, preferentially truncate the longer name. This
* logic could be expressed without a loop, but it's simple and
* obvious as a loop.
*/
while (name1chars + name2chars > availchars)
{
if (name1chars > name2chars)
name1chars--;
else
name2chars--;
}
#ifdef MULTIBYTE
if (name1)
name1chars = pg_mbcliplen(name1, name1chars, name1chars);
if (name2)
name2chars = pg_mbcliplen(name2, name2chars, name2chars);
#endif
/* Now construct the string using the chosen lengths */
name = palloc(name1chars + name2chars + overhead + 1);
strncpy(name, name1, name1chars);
ndx = name1chars;
if (name2)
{
name[ndx++] = '_';
strncpy(name + ndx, name2, name2chars);
ndx += name2chars;
}
if (typename)
{
name[ndx++] = '_';
strcpy(name + ndx, typename);
}
else
name[ndx] = '\0';
return name;
}
static char *
CreateIndexName(char *table_name, char *column_name,
char *label, List *indices)
{
int pass = 0;
char *iname = NULL;
List *ilist;
char typename[NAMEDATALEN];
/*
* The type name for makeObjectName is label, or labelN if that's
* necessary to prevent collisions among multiple indexes for the same
* table. Note there is no check for collisions with already-existing
* indexes, only among the indexes we're about to create now; this
* ought to be improved someday.
*/
strcpy(typename, label);
for (;;)
{
iname = makeObjectName(table_name, column_name, typename);
foreach(ilist, indices)
{
IndexStmt *index = lfirst(ilist);
if (index->idxname != NULL &&
strcmp(iname, index->idxname) == 0)
break;
}
/* ran through entire list? then no name conflict found so done */
if (ilist == NIL)
break;
/* found a conflict, so try a new name component */
pfree(iname);
sprintf(typename, "%s%d", label, ++pass);
}
return iname;
}
/*
* transformCreateStmt -
* transforms the "create table" statement
* SQL92 allows constraints to be scattered all over, so thumb through
* the columns and collect all constraints into one place.
* If there are any implied indices (e.g. UNIQUE or PRIMARY KEY)
* then expand those into multiple IndexStmt blocks.
* - thomas 1997-12-02
*/
static Query *
transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
{
CreateStmtContext cxt;
Query *q;
List *elements;
cxt.stmtType = "CREATE TABLE";
cxt.relname = stmt->relname;
cxt.inhRelnames = stmt->inhRelnames;
cxt.istemp = stmt->istemp;
cxt.hasoids = stmt->hasoids;
cxt.relOid = InvalidOid;
cxt.columns = NIL;
cxt.ckconstraints = NIL;
cxt.fkconstraints = NIL;
cxt.ixconstraints = NIL;
cxt.blist = NIL;
cxt.alist = NIL;
cxt.pkey = NULL;
/*
* Run through each primary element in the table creation clause.
* Separate column defs from constraints, and do preliminary analysis.
*/
foreach(elements, stmt->tableElts)
{
Node *element = lfirst(elements);
switch (nodeTag(element))
{
case T_ColumnDef:
transformColumnDefinition(pstate, &cxt,
(ColumnDef *) element);
break;
case T_Constraint:
transformTableConstraint(pstate, &cxt,
(Constraint *) element);
break;
case T_FkConstraint:
/* No pre-transformation needed */
cxt.fkconstraints = lappend(cxt.fkconstraints, element);
break;
default:
elog(ERROR, "parser: unrecognized node (internal error)");
}
}
Assert(stmt->constraints == NIL);
/*
* Postprocess constraints that give rise to index definitions.
*/
transformIndexConstraints(pstate, &cxt);
/*
* Postprocess foreign-key constraints.
*/
transformFKConstraints(pstate, &cxt);
/*
* Output results.
*/
q = makeNode(Query);
q->commandType = CMD_UTILITY;
q->utilityStmt = (Node *) stmt;
stmt->tableElts = cxt.columns;
stmt->constraints = cxt.ckconstraints;
extras_before = cxt.blist;
extras_after = cxt.alist;
return q;
}
static void
transformColumnDefinition(ParseState *pstate, CreateStmtContext *cxt,
ColumnDef *column)
{
bool is_serial;
bool saw_nullable;
Constraint *constraint;
List *clist;
Ident *key;
cxt->columns = lappend(cxt->columns, column);
/* Check for SERIAL pseudo-types */
is_serial = false;
if (strcmp(column->typename->name, "serial") == 0 ||
strcmp(column->typename->name, "serial4") == 0)
{
is_serial = true;
column->typename->name = pstrdup("int4");
}
else if (strcmp(column->typename->name, "bigserial") == 0 ||
strcmp(column->typename->name, "serial8") == 0)
{
is_serial = true;
column->typename->name = pstrdup("int8");
}
/* Do necessary work on the column type declaration */
transformColumnType(pstate, column);
/* Special actions for SERIAL pseudo-types */
if (is_serial)
{
char *sname;
char *qstring;
A_Const *snamenode;
FuncCall *funccallnode;
CreateSeqStmt *sequence;
/*
* Create appropriate constraints for SERIAL. We do this in full,
* rather than shortcutting, so that we will detect any
* conflicting constraints the user wrote (like a different
* DEFAULT).
*/
sname = makeObjectName(cxt->relname, column->colname, "seq");
/*
* Create an expression tree representing the function call
* nextval('"sequencename"')
*/
qstring = palloc(strlen(sname) + 2 + 1);
sprintf(qstring, "\"%s\"", sname);
snamenode = makeNode(A_Const);
snamenode->val.type = T_String;
snamenode->val.val.str = qstring;
funccallnode = makeNode(FuncCall);
funccallnode->funcname = "nextval";
funccallnode->args = makeList1(snamenode);
funccallnode->agg_star = false;
funccallnode->agg_distinct = false;
constraint = makeNode(Constraint);
constraint->contype = CONSTR_DEFAULT;
constraint->name = sname;
constraint->raw_expr = (Node *) funccallnode;
constraint->cooked_expr = NULL;
constraint->keys = NIL;
column->constraints = lappend(column->constraints, constraint);
constraint = makeNode(Constraint);
constraint->contype = CONSTR_UNIQUE;
constraint->name = NULL; /* assign later */
column->constraints = lappend(column->constraints, constraint);
constraint = makeNode(Constraint);
constraint->contype = CONSTR_NOTNULL;
column->constraints = lappend(column->constraints, constraint);
/*
* Build a CREATE SEQUENCE command to create the sequence object,
* and add it to the list of things to be done before this
* CREATE/ALTER TABLE.
*/
sequence = makeNode(CreateSeqStmt);
sequence->seqname = pstrdup(sname);
sequence->istemp = cxt->istemp;
sequence->options = NIL;
elog(NOTICE, "%s will create implicit sequence '%s' for SERIAL column '%s.%s'",
cxt->stmtType, sequence->seqname, cxt->relname, column->colname);
cxt->blist = lappend(cxt->blist, sequence);
}
/* Process column constraints, if any... */
transformConstraintAttrs(column->constraints);
saw_nullable = false;
foreach(clist, column->constraints)
{
constraint = lfirst(clist);
/*
* If this column constraint is a FOREIGN KEY constraint, then we
* fill in the current attributes name and throw it into the list
* of FK constraints to be processed later.
*/
if (IsA(constraint, FkConstraint))
{
FkConstraint *fkconstraint = (FkConstraint *) constraint;
Ident *id = makeNode(Ident);
id->name = column->colname;
id->indirection = NIL;
id->isRel = false;
fkconstraint->fk_attrs = makeList1(id);
cxt->fkconstraints = lappend(cxt->fkconstraints, fkconstraint);
continue;
}
Assert(IsA(constraint, Constraint));
switch (constraint->contype)
{
case CONSTR_NULL:
if (saw_nullable && column->is_not_null)
elog(ERROR, "%s/(NOT) NULL conflicting declaration for '%s.%s'",
cxt->stmtType, cxt->relname, column->colname);
column->is_not_null = FALSE;
saw_nullable = true;
break;
case CONSTR_NOTNULL:
if (saw_nullable && !column->is_not_null)
elog(ERROR, "%s/(NOT) NULL conflicting declaration for '%s.%s'",
cxt->stmtType, cxt->relname, column->colname);
column->is_not_null = TRUE;
saw_nullable = true;
break;
case CONSTR_DEFAULT:
if (column->raw_default != NULL)
elog(ERROR, "%s/DEFAULT multiple values specified for '%s.%s'",
cxt->stmtType, cxt->relname, column->colname);
column->raw_default = constraint->raw_expr;
Assert(constraint->cooked_expr == NULL);
break;
case CONSTR_PRIMARY:
if (constraint->name == NULL)
constraint->name = makeObjectName(cxt->relname,
NULL,
"pkey");
if (constraint->keys == NIL)
{
key = makeNode(Ident);
key->name = pstrdup(column->colname);
constraint->keys = makeList1(key);
}
cxt->ixconstraints = lappend(cxt->ixconstraints, constraint);
break;
case CONSTR_UNIQUE:
if (constraint->name == NULL)
constraint->name = makeObjectName(cxt->relname,
column->colname,
"key");
if (constraint->keys == NIL)
{
key = makeNode(Ident);
key->name = pstrdup(column->colname);
constraint->keys = makeList1(key);
}
cxt->ixconstraints = lappend(cxt->ixconstraints, constraint);
break;
case CONSTR_CHECK:
if (constraint->name == NULL)
constraint->name = makeObjectName(cxt->relname,
column->colname,
NULL);
cxt->ckconstraints = lappend(cxt->ckconstraints, constraint);
break;
case CONSTR_ATTR_DEFERRABLE:
case CONSTR_ATTR_NOT_DEFERRABLE:
case CONSTR_ATTR_DEFERRED:
case CONSTR_ATTR_IMMEDIATE:
/* transformConstraintAttrs took care of these */
break;
default:
elog(ERROR, "parser: unrecognized constraint (internal error)");
break;
}
}
}
static void
transformTableConstraint(ParseState *pstate, CreateStmtContext *cxt,
Constraint *constraint)
{
switch (constraint->contype)
{
case CONSTR_PRIMARY:
if (constraint->name == NULL)
constraint->name = makeObjectName(cxt->relname,
NULL,
"pkey");
cxt->ixconstraints = lappend(cxt->ixconstraints, constraint);
break;
case CONSTR_UNIQUE:
cxt->ixconstraints = lappend(cxt->ixconstraints, constraint);
break;
case CONSTR_CHECK:
cxt->ckconstraints = lappend(cxt->ckconstraints, constraint);
break;
case CONSTR_NULL:
case CONSTR_NOTNULL:
case CONSTR_DEFAULT:
case CONSTR_ATTR_DEFERRABLE:
case CONSTR_ATTR_NOT_DEFERRABLE:
case CONSTR_ATTR_DEFERRED:
case CONSTR_ATTR_IMMEDIATE:
elog(ERROR, "parser: illegal context for constraint (internal error)");
break;
default:
elog(ERROR, "parser: unrecognized constraint (internal error)");
break;
}
}
static void
transformIndexConstraints(ParseState *pstate, CreateStmtContext *cxt)
{
List *listptr;
List *keys;
IndexStmt *index;
IndexElem *iparam;
ColumnDef *column;
List *columns;
List *indexlist = NIL;
/*
* Run through the constraints that need to generate an index. For
* PRIMARY KEY, mark each column as NOT NULL and create an index. For
* UNIQUE, create an index as for PRIMARY KEY, but do not insist on
* NOT NULL.
*/
foreach(listptr, cxt->ixconstraints)
{
Constraint *constraint = lfirst(listptr);
Assert(IsA(constraint, Constraint));
Assert((constraint->contype == CONSTR_PRIMARY)
|| (constraint->contype == CONSTR_UNIQUE));
index = makeNode(IndexStmt);
index->unique = true;
index->primary = (constraint->contype == CONSTR_PRIMARY);
if (index->primary)
{
/* In ALTER TABLE case, a primary index might already exist */
if (cxt->pkey != NULL ||
(OidIsValid(cxt->relOid) &&
relationHasPrimaryKey(cxt->relname)))
elog(ERROR, "%s / PRIMARY KEY multiple primary keys"
" for table '%s' are not allowed",
cxt->stmtType, cxt->relname);
cxt->pkey = index;
}
if (constraint->name != NULL)
index->idxname = pstrdup(constraint->name);
else if (constraint->contype == CONSTR_PRIMARY)
index->idxname = makeObjectName(cxt->relname, NULL, "pkey");
else
index->idxname = NULL; /* will set it later */
index->relname = cxt->relname;
index->accessMethod = "btree";
index->indexParams = NIL;
index->whereClause = NULL;
/*
* Make sure referenced keys exist. If we are making a PRIMARY
* KEY index, also make sure they are NOT NULL.
*/
foreach(keys, constraint->keys)
{
Ident *key = (Ident *) lfirst(keys);
bool found = false;
Assert(IsA(key, Ident));
column = NULL;
foreach(columns, cxt->columns)
{
column = lfirst(columns);
Assert(IsA(column, ColumnDef));
if (strcmp(column->colname, key->name) == 0)
{
found = true;
break;
}
}
if (found)
{
/* found column in the new table; force it to be NOT NULL */
if (constraint->contype == CONSTR_PRIMARY)
column->is_not_null = TRUE;
}
else if (SystemAttributeByName(key->name, cxt->hasoids) != NULL)
{
/*
* column will be a system column in the new table, so
* accept it. System columns can't ever be null, so no
* need to worry about PRIMARY/NOT NULL constraint.
*/
found = true;
}
else if (cxt->inhRelnames)
{
/* try inherited tables */
List *inher;
foreach(inher, cxt->inhRelnames)
{
Value *inh = lfirst(inher);
Relation rel;
int count;
Assert(IsA(inh, String));
rel = heap_openr(strVal(inh), AccessShareLock);
if (rel->rd_rel->relkind != RELKIND_RELATION)
elog(ERROR, "inherited table \"%s\" is not a relation",
strVal(inh));
for (count = 0; count < rel->rd_att->natts; count++)
{
Form_pg_attribute inhattr = rel->rd_att->attrs[count];
char *inhname = NameStr(inhattr->attname);
if (strcmp(key->name, inhname) == 0)
{
found = true;
/*
* If the column is inherited, we currently
* have no easy way to force it to be NOT
* NULL. Only way I can see to fix this would
* be to convert the inherited-column info to
* ColumnDef nodes before we reach this point,
* and then create the table from those nodes
* rather than referencing the parent tables
* later. That would likely be cleaner, but
* too much work to contemplate right now.
* Instead, raise an error if the inherited
* column won't be NOT NULL. (Would a NOTICE
* be more reasonable?)
*/
if (constraint->contype == CONSTR_PRIMARY &&
!inhattr->attnotnull)
elog(ERROR, "inherited attribute \"%s\" cannot be a PRIMARY KEY because it is not marked NOT NULL",
inhname);
break;
}
}
heap_close(rel, NoLock);
if (found)
break;
}
}
else if (OidIsValid(cxt->relOid))
{
/* ALTER TABLE case: does column already exist? */
HeapTuple atttuple;
atttuple = SearchSysCache(ATTNAME,
ObjectIdGetDatum(cxt->relOid),
PointerGetDatum(key->name),
0, 0);
if (HeapTupleIsValid(atttuple))
{
found = true;
/*
* We require pre-existing column to be already marked
* NOT NULL.
*/
if (constraint->contype == CONSTR_PRIMARY &&
!((Form_pg_attribute) GETSTRUCT(atttuple))->attnotnull)
elog(ERROR, "Existing attribute \"%s\" cannot be a PRIMARY KEY because it is not marked NOT NULL",
key->name);
ReleaseSysCache(atttuple);
}
}
if (!found)
elog(ERROR, "%s: column \"%s\" named in key does not exist",
cxt->stmtType, key->name);
/* Check for PRIMARY KEY(foo, foo) */
foreach(columns, index->indexParams)
{
iparam = (IndexElem *) lfirst(columns);
if (strcmp(key->name, iparam->name) == 0)
elog(ERROR, "%s: column \"%s\" appears twice in %s constraint",
cxt->stmtType, key->name,
index->primary ? "PRIMARY KEY" : "UNIQUE");
}
/* OK, add it to the index definition */
iparam = makeNode(IndexElem);
iparam->name = pstrdup(key->name);
iparam->args = NIL;
iparam->class = NULL;
index->indexParams = lappend(index->indexParams, iparam);
}
indexlist = lappend(indexlist, index);
}
/*
* Scan the index list and remove any redundant index specifications.
* This can happen if, for instance, the user writes SERIAL PRIMARY
* KEY or SERIAL UNIQUE. A strict reading of SQL92 would suggest
* raising an error instead, but that strikes me as too
* anal-retentive. - tgl 2001-02-14
*
* XXX in ALTER TABLE case, it'd be nice to look for duplicate
* pre-existing indexes, too.
*/
cxt->alist = NIL;
if (cxt->pkey != NULL)
{
/* Make sure we keep the PKEY index in preference to others... */
cxt->alist = makeList1(cxt->pkey);
}
while (indexlist != NIL)
{
index = lfirst(indexlist);
/* if it's pkey, it's already in cxt->alist */
if (index != cxt->pkey)
{
bool keep = true;
List *priorlist;
foreach(priorlist, cxt->alist)
{
IndexStmt *priorindex = lfirst(priorlist);
if (equal(index->indexParams, priorindex->indexParams))
{
/*
* If the prior index is as yet unnamed, and this one
* is named, then transfer the name to the prior
* index. This ensures that if we have named and
* unnamed constraints, we'll use (at least one of)
* the names for the index.
*/
if (priorindex->idxname == NULL)
priorindex->idxname = index->idxname;
keep = false;
break;
}
}
if (keep)
cxt->alist = lappend(cxt->alist, index);
}
indexlist = lnext(indexlist);
}
/*
* Finally, select unique names for all not-previously-named indices,
* and display notice messages.
*
* XXX in ALTER TABLE case, we fail to consider name collisions against
* pre-existing indexes.
*/
foreach(indexlist, cxt->alist)
{
index = lfirst(indexlist);
if (index->idxname == NULL && index->indexParams != NIL)
{
iparam = lfirst(index->indexParams);
index->idxname = CreateIndexName(cxt->relname, iparam->name,
"key", cxt->alist);
}
if (index->idxname == NULL) /* should not happen */
elog(ERROR, "%s: failed to make implicit index name",
cxt->stmtType);
elog(NOTICE, "%s / %s will create implicit index '%s' for table '%s'",
cxt->stmtType, (index->primary ? "ADD PRIMARY KEY" : "ADD UNIQUE"),
index->idxname, cxt->relname);
}
}
static void
transformFKConstraints(ParseState *pstate, CreateStmtContext *cxt)
{
CreateTrigStmt *fk_trigger;
List *fkactions = NIL;
List *fkclist;
List *fk_attr;
List *pk_attr;
Ident *id;
Oid pktypoid[INDEX_MAX_KEYS];
Oid fktypoid[INDEX_MAX_KEYS];
int i;
if (cxt->fkconstraints == NIL)
return;
elog(NOTICE, "%s will create implicit trigger(s) for FOREIGN KEY check(s)",
cxt->stmtType);
foreach(fkclist, cxt->fkconstraints)
{
FkConstraint *fkconstraint = (FkConstraint *) lfirst(fkclist);
int attnum;
List *fkattrs;
/*
* If the constraint has no name, set it to <unnamed>
*/
if (fkconstraint->constr_name == NULL)
fkconstraint->constr_name = "<unnamed>";
for (attnum = 0; attnum < INDEX_MAX_KEYS; attnum++)
pktypoid[attnum] = fktypoid[attnum] = InvalidOid;
/*
* Look up the referencing attributes to make sure they exist (or
* will exist) in this table, and remember their type OIDs.
*/
attnum = 0;
foreach(fkattrs, fkconstraint->fk_attrs)
{
Ident *fkattr = lfirst(fkattrs);
if (attnum >= INDEX_MAX_KEYS)
elog(ERROR, "Can only have %d keys in a foreign key",
INDEX_MAX_KEYS);
fktypoid[attnum++] = transformFkeyGetColType(cxt,
fkattr->name);
}
/*
* If the attribute list for the referenced table was omitted,
* lookup the definition of the primary key.
*/
if (fkconstraint->pk_attrs == NIL)
{
if (strcmp(fkconstraint->pktable_name, cxt->relname) != 0)
transformFkeyGetPrimaryKey(fkconstraint, pktypoid);
else if (cxt->pkey != NULL)
{
/* Use the to-be-created primary key */
List *attr;
attnum = 0;
foreach(attr, cxt->pkey->indexParams)
{
IndexElem *ielem = lfirst(attr);
Ident *pkattr = (Ident *) makeNode(Ident);
pkattr->name = pstrdup(ielem->name);
pkattr->indirection = NIL;
pkattr->isRel = false;
fkconstraint->pk_attrs = lappend(fkconstraint->pk_attrs,
pkattr);
if (attnum >= INDEX_MAX_KEYS)
elog(ERROR, "Can only have %d keys in a foreign key",
INDEX_MAX_KEYS);
pktypoid[attnum++] = transformFkeyGetColType(cxt,
ielem->name);
}
}
else
{
/* In ALTER TABLE case, primary key may already exist */
if (OidIsValid(cxt->relOid))
transformFkeyGetPrimaryKey(fkconstraint, pktypoid);
else
elog(ERROR, "PRIMARY KEY for referenced table \"%s\" not found",
fkconstraint->pktable_name);
}
}
else
{
/* Validate the specified referenced key list */
if (strcmp(fkconstraint->pktable_name, cxt->relname) != 0)
transformFkeyCheckAttrs(fkconstraint, pktypoid);
else
{
/* Look for a matching new unique/primary constraint */
List *index;
bool found = false;
foreach(index, cxt->alist)
{
IndexStmt *ind = lfirst(index);
List *pkattrs;
if (!ind->unique)
continue;
if (length(ind->indexParams) !=
length(fkconstraint->pk_attrs))
continue;
attnum = 0;
foreach(pkattrs, fkconstraint->pk_attrs)
{
Ident *pkattr = lfirst(pkattrs);
List *indparms;
found = false;
foreach(indparms, ind->indexParams)
{
IndexElem *indparm = lfirst(indparms);
if (strcmp(indparm->name, pkattr->name) == 0)
{
found = true;
break;
}
}
if (!found)
break;
if (attnum >= INDEX_MAX_KEYS)
elog(ERROR, "Can only have %d keys in a foreign key",
INDEX_MAX_KEYS);
pktypoid[attnum++] = transformFkeyGetColType(cxt,
pkattr->name);
}
if (found)
break;
}
if (!found)
{
/*
* In ALTER TABLE case, such an index may already
* exist
*/
if (OidIsValid(cxt->relOid))
transformFkeyCheckAttrs(fkconstraint, pktypoid);
else
elog(ERROR, "UNIQUE constraint matching given keys for referenced table \"%s\" not found",
fkconstraint->pktable_name);
}
}
}
/* Be sure referencing and referenced column types are comparable */
for (i = 0; i < INDEX_MAX_KEYS && fktypoid[i] != 0; i++)
{
/*
* fktypoid[i] is the foreign key table's i'th element's type
* oid pktypoid[i] is the primary key table's i'th element's
* type oid We let oper() do our work for us, including
* elog(ERROR) if the types don't compare with =
*/
Operator o = oper("=", fktypoid[i], pktypoid[i], false);
ReleaseSysCache(o);
}
/*
* Build a CREATE CONSTRAINT TRIGGER statement for the CHECK
* action.
*/
fk_trigger = (CreateTrigStmt *) makeNode(CreateTrigStmt);
fk_trigger->trigname = fkconstraint->constr_name;
fk_trigger->relname = cxt->relname;
fk_trigger->funcname = "RI_FKey_check_ins";
fk_trigger->before = false;
fk_trigger->row = true;
fk_trigger->actions[0] = 'i';
fk_trigger->actions[1] = 'u';
fk_trigger->actions[2] = '\0';
fk_trigger->lang = NULL;
fk_trigger->text = NULL;
fk_trigger->attr = NIL;
fk_trigger->when = NULL;
fk_trigger->isconstraint = true;
fk_trigger->deferrable = fkconstraint->deferrable;
fk_trigger->initdeferred = fkconstraint->initdeferred;
fk_trigger->constrrelname = fkconstraint->pktable_name;
fk_trigger->args = NIL;
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->constr_name));
fk_trigger->args = lappend(fk_trigger->args,
makeString(cxt->relname));
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->pktable_name));
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->match_type));
fk_attr = fkconstraint->fk_attrs;
pk_attr = fkconstraint->pk_attrs;
if (length(fk_attr) != length(pk_attr))
elog(ERROR, "number of key attributes in referenced table must be equal to foreign key"
"\n\tIllegal FOREIGN KEY definition references \"%s\"",
fkconstraint->pktable_name);
while (fk_attr != NIL)
{
id = (Ident *) lfirst(fk_attr);
fk_trigger->args = lappend(fk_trigger->args,
makeString(id->name));
id = (Ident *) lfirst(pk_attr);
fk_trigger->args = lappend(fk_trigger->args,
makeString(id->name));
fk_attr = lnext(fk_attr);
pk_attr = lnext(pk_attr);
}
fkactions = lappend(fkactions, (Node *) fk_trigger);
/*
* Build a CREATE CONSTRAINT TRIGGER statement for the ON DELETE
* action fired on the PK table !!!
*/
fk_trigger = (CreateTrigStmt *) makeNode(CreateTrigStmt);
fk_trigger->trigname = fkconstraint->constr_name;
fk_trigger->relname = fkconstraint->pktable_name;
fk_trigger->before = false;
fk_trigger->row = true;
fk_trigger->actions[0] = 'd';
fk_trigger->actions[1] = '\0';
fk_trigger->lang = NULL;
fk_trigger->text = NULL;
fk_trigger->attr = NIL;
fk_trigger->when = NULL;
fk_trigger->isconstraint = true;
fk_trigger->deferrable = fkconstraint->deferrable;
fk_trigger->initdeferred = fkconstraint->initdeferred;
fk_trigger->constrrelname = cxt->relname;
switch ((fkconstraint->actions & FKCONSTR_ON_DELETE_MASK)
>> FKCONSTR_ON_DELETE_SHIFT)
{
case FKCONSTR_ON_KEY_NOACTION:
fk_trigger->funcname = "RI_FKey_noaction_del";
break;
case FKCONSTR_ON_KEY_RESTRICT:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = "RI_FKey_restrict_del";
break;
case FKCONSTR_ON_KEY_CASCADE:
fk_trigger->funcname = "RI_FKey_cascade_del";
break;
case FKCONSTR_ON_KEY_SETNULL:
fk_trigger->funcname = "RI_FKey_setnull_del";
break;
case FKCONSTR_ON_KEY_SETDEFAULT:
fk_trigger->funcname = "RI_FKey_setdefault_del";
break;
default:
elog(ERROR, "Only one ON DELETE action can be specified for FOREIGN KEY constraint");
break;
}
fk_trigger->args = NIL;
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->constr_name));
fk_trigger->args = lappend(fk_trigger->args,
makeString(cxt->relname));
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->pktable_name));
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->match_type));
fk_attr = fkconstraint->fk_attrs;
pk_attr = fkconstraint->pk_attrs;
while (fk_attr != NIL)
{
id = (Ident *) lfirst(fk_attr);
fk_trigger->args = lappend(fk_trigger->args,
makeString(id->name));
id = (Ident *) lfirst(pk_attr);
fk_trigger->args = lappend(fk_trigger->args,
makeString(id->name));
fk_attr = lnext(fk_attr);
pk_attr = lnext(pk_attr);
}
fkactions = lappend(fkactions, (Node *) fk_trigger);
/*
* Build a CREATE CONSTRAINT TRIGGER statement for the ON UPDATE
* action fired on the PK table !!!
*/
fk_trigger = (CreateTrigStmt *) makeNode(CreateTrigStmt);
fk_trigger->trigname = fkconstraint->constr_name;
fk_trigger->relname = fkconstraint->pktable_name;
fk_trigger->before = false;
fk_trigger->row = true;
fk_trigger->actions[0] = 'u';
fk_trigger->actions[1] = '\0';
fk_trigger->lang = NULL;
fk_trigger->text = NULL;
fk_trigger->attr = NIL;
fk_trigger->when = NULL;
fk_trigger->isconstraint = true;
fk_trigger->deferrable = fkconstraint->deferrable;
fk_trigger->initdeferred = fkconstraint->initdeferred;
fk_trigger->constrrelname = cxt->relname;
switch ((fkconstraint->actions & FKCONSTR_ON_UPDATE_MASK)
>> FKCONSTR_ON_UPDATE_SHIFT)
{
case FKCONSTR_ON_KEY_NOACTION:
fk_trigger->funcname = "RI_FKey_noaction_upd";
break;
case FKCONSTR_ON_KEY_RESTRICT:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = "RI_FKey_restrict_upd";
break;
case FKCONSTR_ON_KEY_CASCADE:
fk_trigger->funcname = "RI_FKey_cascade_upd";
break;
case FKCONSTR_ON_KEY_SETNULL:
fk_trigger->funcname = "RI_FKey_setnull_upd";
break;
case FKCONSTR_ON_KEY_SETDEFAULT:
fk_trigger->funcname = "RI_FKey_setdefault_upd";
break;
default:
elog(ERROR, "Only one ON UPDATE action can be specified for FOREIGN KEY constraint");
break;
}
fk_trigger->args = NIL;
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->constr_name));
fk_trigger->args = lappend(fk_trigger->args,
makeString(cxt->relname));
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->pktable_name));
fk_trigger->args = lappend(fk_trigger->args,
makeString(fkconstraint->match_type));
fk_attr = fkconstraint->fk_attrs;
pk_attr = fkconstraint->pk_attrs;
while (fk_attr != NIL)
{
id = (Ident *) lfirst(fk_attr);
fk_trigger->args = lappend(fk_trigger->args,
makeString(id->name));
id = (Ident *) lfirst(pk_attr);
fk_trigger->args = lappend(fk_trigger->args,
makeString(id->name));
fk_attr = lnext(fk_attr);
pk_attr = lnext(pk_attr);
}
fkactions = lappend(fkactions, (Node *) fk_trigger);
}
/*
* Attach completed list of extra actions to cxt->alist. We cannot do
* this earlier, because we assume above that cxt->alist still holds
* only IndexStmts.
*/
cxt->alist = nconc(cxt->alist, fkactions);
}
/*
* transformIndexStmt -
* transforms the qualification of the index statement
*/
static Query *
transformIndexStmt(ParseState *pstate, IndexStmt *stmt)
{
Query *qry;
RangeTblEntry *rte;
qry = makeNode(Query);
qry->commandType = CMD_UTILITY;
/* take care of the where clause */
if (stmt->whereClause)
{
/*
* Put the parent table into the rtable so that the WHERE clause
* can refer to its fields without qualification. Note that this
* only works if the parent table already exists --- so we can't
* easily support predicates on indexes created implicitly by
* CREATE TABLE. Fortunately, that's not necessary.
*/
rte = addRangeTableEntry(pstate, stmt->relname, NULL, false, true);
/* no to join list, yes to namespace */
addRTEtoQuery(pstate, rte, false, true);
stmt->whereClause = transformWhereClause(pstate, stmt->whereClause);
}
qry->hasSubLinks = pstate->p_hasSubLinks;
stmt->rangetable = pstate->p_rtable;
qry->utilityStmt = (Node *) stmt;
return qry;
}
/*
* transformRuleStmt -
* transform a Create Rule Statement. The actions is a list of parse
* trees which is transformed into a list of query trees.
*/
static Query *
transformRuleStmt(ParseState *pstate, RuleStmt *stmt)
{
Query *qry;
RangeTblEntry *oldrte;
RangeTblEntry *newrte;
qry = makeNode(Query);
qry->commandType = CMD_UTILITY;
qry->utilityStmt = (Node *) stmt;
/*
* To avoid deadlock, make sure the first thing we do is grab
* AccessExclusiveLock on the target relation. This will be needed by
* DefineQueryRewrite(), and we don't want to grab a lesser lock
* beforehand. We don't need to hold a refcount on the relcache
* entry, however.
*/
heap_close(heap_openr(stmt->object->relname, AccessExclusiveLock),
NoLock);
/*
* NOTE: 'OLD' must always have a varno equal to 1 and 'NEW' equal to
* 2. Set up their RTEs in the main pstate for use in parsing the
* rule qualification.
*/
Assert(pstate->p_rtable == NIL);
oldrte = addRangeTableEntry(pstate, stmt->object->relname,
makeAttr("*OLD*", NULL),
false, true);
newrte = addRangeTableEntry(pstate, stmt->object->relname,
makeAttr("*NEW*", NULL),
false, true);
/* Must override addRangeTableEntry's default access-check flags */
oldrte->checkForRead = false;
newrte->checkForRead = false;
/*
* They must be in the namespace too for lookup purposes, but only add
* the one(s) that are relevant for the current kind of rule. In an
* UPDATE rule, quals must refer to OLD.field or NEW.field to be
* unambiguous, but there's no need to be so picky for INSERT &
* DELETE. (Note we marked the RTEs "inFromCl = true" above to allow
* unqualified references to their fields.) We do not add them to the
* joinlist.
*/
switch (stmt->event)
{
case CMD_SELECT:
addRTEtoQuery(pstate, oldrte, false, true);
break;
case CMD_UPDATE:
addRTEtoQuery(pstate, oldrte, false, true);
addRTEtoQuery(pstate, newrte, false, true);
break;
case CMD_INSERT:
addRTEtoQuery(pstate, newrte, false, true);
break;
case CMD_DELETE:
addRTEtoQuery(pstate, oldrte, false, true);
break;
default:
elog(ERROR, "transformRuleStmt: unexpected event type %d",
(int) stmt->event);
break;
}
/* take care of the where clause */
stmt->whereClause = transformWhereClause(pstate, stmt->whereClause);
if (length(pstate->p_rtable) != 2) /* naughty, naughty... */
elog(ERROR, "Rule WHERE condition may not contain references to other relations");
/* save info about sublinks in where clause */
qry->hasSubLinks = pstate->p_hasSubLinks;
/*
* 'instead nothing' rules with a qualification need a query
* rangetable so the rewrite handler can add the negated rule
* qualification to the original query. We create a query with the new
* command type CMD_NOTHING here that is treated specially by the
* rewrite system.
*/
if (stmt->actions == NIL)
{
Query *nothing_qry = makeNode(Query);
nothing_qry->commandType = CMD_NOTHING;
nothing_qry->rtable = pstate->p_rtable;
nothing_qry->jointree = makeFromExpr(NIL, NULL); /* no join wanted */
stmt->actions = makeList1(nothing_qry);
}
else
{
List *oldactions;
List *newactions = NIL;
/*
* transform each statement, like parse_analyze()
*/
foreach(oldactions, stmt->actions)
{
Node *action = (Node *) lfirst(oldactions);
ParseState *sub_pstate = make_parsestate(pstate->parentParseState);
Query *sub_qry,
*top_subqry;
bool has_old,
has_new;
/*
* Set up OLD/NEW in the rtable for this statement. The
* entries are marked not inFromCl because we don't want them
* to be referred to by unqualified field names nor "*" in the
* rule actions. We must add them to the namespace, however,
* or they won't be accessible at all. We decide later
* whether to put them in the joinlist.
*/
oldrte = addRangeTableEntry(sub_pstate, stmt->object->relname,
makeAttr("*OLD*", NULL),
false, false);
newrte = addRangeTableEntry(sub_pstate, stmt->object->relname,
makeAttr("*NEW*", NULL),
false, false);
oldrte->checkForRead = false;
newrte->checkForRead = false;
addRTEtoQuery(sub_pstate, oldrte, false, true);
addRTEtoQuery(sub_pstate, newrte, false, true);
/* Transform the rule action statement */
top_subqry = transformStmt(sub_pstate, action);
/*
* We cannot support utility-statement actions (eg NOTIFY)
* with nonempty rule WHERE conditions, because there's no way
* to make the utility action execute conditionally.
*/
if (top_subqry->commandType == CMD_UTILITY &&
stmt->whereClause != NULL)
elog(ERROR, "Rules with WHERE conditions may only have SELECT, INSERT, UPDATE, or DELETE actions");
/*
* If the action is INSERT...SELECT, OLD/NEW have been pushed
* down into the SELECT, and that's what we need to look at.
* (Ugly kluge ... try to fix this when we redesign
* querytrees.)
*/
sub_qry = getInsertSelectQuery(top_subqry, NULL);
/*
* Validate action's use of OLD/NEW, qual too
*/
has_old =
rangeTableEntry_used((Node *) sub_qry, PRS2_OLD_VARNO, 0) ||
rangeTableEntry_used(stmt->whereClause, PRS2_OLD_VARNO, 0);
has_new =
rangeTableEntry_used((Node *) sub_qry, PRS2_NEW_VARNO, 0) ||
rangeTableEntry_used(stmt->whereClause, PRS2_NEW_VARNO, 0);
switch (stmt->event)
{
case CMD_SELECT:
if (has_old)
elog(ERROR, "ON SELECT rule may not use OLD");
if (has_new)
elog(ERROR, "ON SELECT rule may not use NEW");
break;
case CMD_UPDATE:
/* both are OK */
break;
case CMD_INSERT:
if (has_old)
elog(ERROR, "ON INSERT rule may not use OLD");
break;
case CMD_DELETE:
if (has_new)
elog(ERROR, "ON DELETE rule may not use NEW");
break;
default:
elog(ERROR, "transformRuleStmt: unexpected event type %d",
(int) stmt->event);
break;
}
/*
* For efficiency's sake, add OLD to the rule action's
* jointree only if it was actually referenced in the
* statement or qual.
*
* For INSERT, NEW is not really a relation (only a reference to
* the to-be-inserted tuple) and should never be added to the
* jointree.
*
* For UPDATE, we treat NEW as being another kind of reference to
* OLD, because it represents references to *transformed*
* tuples of the existing relation. It would be wrong to
* enter NEW separately in the jointree, since that would
* cause a double join of the updated relation. It's also
* wrong to fail to make a jointree entry if only NEW and not
* OLD is mentioned.
*/
if (has_old || (has_new && stmt->event == CMD_UPDATE))
{
/* hack so we can use addRTEtoQuery() */
sub_pstate->p_rtable = sub_qry->rtable;
sub_pstate->p_joinlist = sub_qry->jointree->fromlist;
addRTEtoQuery(sub_pstate, oldrte, true, false);
sub_qry->jointree->fromlist = sub_pstate->p_joinlist;
}
newactions = lappend(newactions, top_subqry);
release_pstate_resources(sub_pstate);
pfree(sub_pstate);
}
stmt->actions = newactions;
}
return qry;
}
/*
* transformSelectStmt -
* transforms a Select Statement
*
* Note: this is also used for DECLARE CURSOR statements.
*/
static Query *
transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
{
Query *qry = makeNode(Query);
Node *qual;
qry->commandType = CMD_SELECT;
if (stmt->portalname)
{
/* DECLARE CURSOR */
if (stmt->into)
elog(ERROR, "DECLARE CURSOR must not specify INTO");
if (stmt->forUpdate)
elog(ERROR, "DECLARE/UPDATE is not supported"
"\n\tCursors must be READ ONLY");
/*
* 15 august 1991 -- since 3.0 postgres does locking right, we
* discovered that portals were violating locking protocol. portal
* locks cannot span xacts. as a short-term fix, we installed the
* check here. -- mao
*/
if (!IsTransactionBlock())
elog(ERROR, "DECLARE CURSOR may only be used in begin/end transaction blocks");
qry->into = stmt->portalname;
qry->isTemp = stmt->istemp;
qry->isPortal = TRUE;
qry->isBinary = stmt->binary; /* internal portal */
}
else
{
/* SELECT */
qry->into = stmt->into;
qry->isTemp = stmt->istemp;
qry->isPortal = FALSE;
qry->isBinary = FALSE;
}
/* make FOR UPDATE clause available to addRangeTableEntry */
pstate->p_forUpdate = stmt->forUpdate;
/* process the FROM clause */
transformFromClause(pstate, stmt->fromClause);
/* transform targetlist and WHERE */
qry->targetList = transformTargetList(pstate, stmt->targetList);
qual = transformWhereClause(pstate, stmt->whereClause);
/*
* Initial processing of HAVING clause is just like WHERE clause.
* Additional work will be done in optimizer/plan/planner.c.
*/
qry->havingQual = transformWhereClause(pstate, stmt->havingClause);
qry->groupClause = transformGroupClause(pstate,
stmt->groupClause,
qry->targetList);
qry->sortClause = transformSortClause(pstate,
stmt->sortClause,
qry->targetList);
qry->distinctClause = transformDistinctClause(pstate,
stmt->distinctClause,
qry->targetList,
&qry->sortClause);
qry->limitOffset = stmt->limitOffset;
qry->limitCount = stmt->limitCount;
qry->hasSubLinks = pstate->p_hasSubLinks;
qry->hasAggs = pstate->p_hasAggs;
if (pstate->p_hasAggs || qry->groupClause || qry->havingQual)
parseCheckAggregates(pstate, qry, qual);
qry->rtable = pstate->p_rtable;
qry->jointree = makeFromExpr(pstate->p_joinlist, qual);
if (stmt->forUpdate != NIL)
transformForUpdate(qry, stmt->forUpdate);
return qry;
}
/*
* transformSetOperationsStmt -
* transforms a set-operations tree
*
* A set-operation tree is just a SELECT, but with UNION/INTERSECT/EXCEPT
* structure to it. We must transform each leaf SELECT and build up a top-
* level Query that contains the leaf SELECTs as subqueries in its rangetable.
* The tree of set operations is converted into the setOperations field of
* the top-level Query.
*/
static Query *
transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
{
Query *qry = makeNode(Query);
SelectStmt *leftmostSelect;
int leftmostRTI;
Query *leftmostQuery;
SetOperationStmt *sostmt;
char *into;
bool istemp;
char *portalname;
bool binary;
List *sortClause;
Node *limitOffset;
Node *limitCount;
List *forUpdate;
Node *node;
List *lefttl,
*dtlist,
*targetvars,
*targetnames,
*sv_namespace;
JoinExpr *jnode;
int tllen;
qry->commandType = CMD_SELECT;
/*
* Find leftmost leaf SelectStmt; extract the one-time-only items from
* it and from the top-level node.
*/
leftmostSelect = stmt->larg;
while (leftmostSelect && leftmostSelect->op != SETOP_NONE)
leftmostSelect = leftmostSelect->larg;
Assert(leftmostSelect && IsA(leftmostSelect, SelectStmt) &&
leftmostSelect->larg == NULL);
into = leftmostSelect->into;
istemp = leftmostSelect->istemp;
portalname = stmt->portalname;
binary = stmt->binary;
/* clear them to prevent complaints in transformSetOperationTree() */
leftmostSelect->into = NULL;
leftmostSelect->istemp = false;
stmt->portalname = NULL;
stmt->binary = false;
/*
* These are not one-time, exactly, but we want to process them here
* and not let transformSetOperationTree() see them --- else it'll
* just recurse right back here!
*/
sortClause = stmt->sortClause;
limitOffset = stmt->limitOffset;
limitCount = stmt->limitCount;
forUpdate = stmt->forUpdate;
stmt->sortClause = NIL;
stmt->limitOffset = NULL;
stmt->limitCount = NULL;
stmt->forUpdate = NIL;
/* We don't support forUpdate with set ops at the moment. */
if (forUpdate)
elog(ERROR, "SELECT FOR UPDATE is not allowed with UNION/INTERSECT/EXCEPT");
/*
* Recursively transform the components of the tree.
*/
sostmt = (SetOperationStmt *) transformSetOperationTree(pstate, stmt);
Assert(sostmt && IsA(sostmt, SetOperationStmt));
qry->setOperations = (Node *) sostmt;
/*
* Re-find leftmost SELECT (now it's a sub-query in rangetable)
*/
node = sostmt->larg;
while (node && IsA(node, SetOperationStmt))
node = ((SetOperationStmt *) node)->larg;
Assert(node && IsA(node, RangeTblRef));
leftmostRTI = ((RangeTblRef *) node)->rtindex;
leftmostQuery = rt_fetch(leftmostRTI, pstate->p_rtable)->subquery;
Assert(leftmostQuery != NULL);
/*
* Generate dummy targetlist for outer query using column names of
* leftmost select and common datatypes of topmost set operation. Also
* make lists of the dummy vars and their names for use in parsing
* ORDER BY.
*/
qry->targetList = NIL;
targetvars = NIL;
targetnames = NIL;
lefttl = leftmostQuery->targetList;
foreach(dtlist, sostmt->colTypes)
{
Oid colType = (Oid) lfirsti(dtlist);
Resdom *leftResdom = ((TargetEntry *) lfirst(lefttl))->resdom;
char *colName = pstrdup(leftResdom->resname);
Resdom *resdom;
Node *expr;
resdom = makeResdom((AttrNumber) pstate->p_last_resno++,
colType,
-1,
colName,
false);
expr = (Node *) makeVar(leftmostRTI,
leftResdom->resno,
colType,
-1,
0);
qry->targetList = lappend(qry->targetList,
makeTargetEntry(resdom, expr));
targetvars = lappend(targetvars, expr);
targetnames = lappend(targetnames, makeString(colName));
lefttl = lnext(lefttl);
}
/*
* Insert one-time items into top-level query
*
* This needs to agree with transformSelectStmt!
*/
if (portalname)
{
/* DECLARE CURSOR */
if (into)
elog(ERROR, "DECLARE CURSOR must not specify INTO");
if (forUpdate)
elog(ERROR, "DECLARE/UPDATE is not supported"
"\n\tCursors must be READ ONLY");
/*
* 15 august 1991 -- since 3.0 postgres does locking right, we
* discovered that portals were violating locking protocol. portal
* locks cannot span xacts. as a short-term fix, we installed the
* check here. -- mao
*/
if (!IsTransactionBlock())
elog(ERROR, "DECLARE CURSOR may only be used in begin/end transaction blocks");
qry->into = portalname;
qry->isTemp = istemp;
qry->isPortal = TRUE;
qry->isBinary = binary; /* internal portal */
}
else
{
/* SELECT */
qry->into = into;
qry->isTemp = istemp;
qry->isPortal = FALSE;
qry->isBinary = FALSE;
}
/*
* As a first step towards supporting sort clauses that are
* expressions using the output columns, generate a namespace entry
* that makes the output columns visible. A JoinExpr node is handy
* for this, since we can easily control the Vars generated upon
* matches.
*
* Note: we don't yet do anything useful with such cases, but at least
* "ORDER BY upper(foo)" will draw the right error message rather than
* "foo not found".
*/
jnode = makeNode(JoinExpr);
jnode->colnames = targetnames;
jnode->colvars = targetvars;
sv_namespace = pstate->p_namespace;
pstate->p_namespace = makeList1(jnode);
/*
* For now, we don't support resjunk sort clauses on the output of a
* setOperation tree --- you can only use the SQL92-spec options of
* selecting an output column by name or number. Enforce by checking
* that transformSortClause doesn't add any items to tlist.
*/
tllen = length(qry->targetList);
qry->sortClause = transformSortClause(pstate,
sortClause,
qry->targetList);
pstate->p_namespace = sv_namespace;
if (tllen != length(qry->targetList))
elog(ERROR, "ORDER BY on a UNION/INTERSECT/EXCEPT result must be on one of the result columns");
qry->limitOffset = limitOffset;
qry->limitCount = limitCount;
qry->hasSubLinks = pstate->p_hasSubLinks;
qry->hasAggs = pstate->p_hasAggs;
if (pstate->p_hasAggs || qry->groupClause || qry->havingQual)
parseCheckAggregates(pstate, qry, NULL);
qry->rtable = pstate->p_rtable;
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
if (forUpdate != NIL)
transformForUpdate(qry, forUpdate);
return qry;
}
/*
* transformSetOperationTree
* Recursively transform leaves and internal nodes of a set-op tree
*/
static Node *
transformSetOperationTree(ParseState *pstate, SelectStmt *stmt)
{
bool isLeaf;
Assert(stmt && IsA(stmt, SelectStmt));
/*
* Validity-check both leaf and internal SELECTs for disallowed ops.
*/
if (stmt->into)
elog(ERROR, "INTO is only allowed on first SELECT of UNION/INTERSECT/EXCEPT");
if (stmt->portalname) /* should not happen */
elog(ERROR, "Portal may not appear in UNION/INTERSECT/EXCEPT");
/* We don't support forUpdate with set ops at the moment. */
if (stmt->forUpdate)
elog(ERROR, "SELECT FOR UPDATE is not allowed with UNION/INTERSECT/EXCEPT");
/*
* If an internal node of a set-op tree has ORDER BY, UPDATE, or LIMIT
* clauses attached, we need to treat it like a leaf node to generate
* an independent sub-Query tree. Otherwise, it can be represented by
* a SetOperationStmt node underneath the parent Query.
*/
if (stmt->op == SETOP_NONE)
{
Assert(stmt->larg == NULL && stmt->rarg == NULL);
isLeaf = true;
}
else
{
Assert(stmt->larg != NULL && stmt->rarg != NULL);
if (stmt->sortClause || stmt->limitOffset || stmt->limitCount ||
stmt->forUpdate)
isLeaf = true;
else
isLeaf = false;
}
if (isLeaf)
{
/* Process leaf SELECT */
List *selectList;
Query *selectQuery;
char selectName[32];
RangeTblEntry *rte;
RangeTblRef *rtr;
/*
* Transform SelectStmt into a Query.
*
* Note: previously transformed sub-queries don't affect the parsing
* of this sub-query, because they are not in the toplevel
* pstate's namespace list.
*/
selectList = parse_analyze((Node *) stmt, pstate);
Assert(length(selectList) == 1);
selectQuery = (Query *) lfirst(selectList);
/*
* Make the leaf query be a subquery in the top-level rangetable.
*/
sprintf(selectName, "*SELECT* %d", length(pstate->p_rtable) + 1);
rte = addRangeTableEntryForSubquery(pstate,
selectQuery,
makeAttr(pstrdup(selectName),
NULL),
false);
/*
* Return a RangeTblRef to replace the SelectStmt in the set-op
* tree.
*/
rtr = makeNode(RangeTblRef);
/* assume new rte is at end */
rtr->rtindex = length(pstate->p_rtable);
Assert(rte == rt_fetch(rtr->rtindex, pstate->p_rtable));
return (Node *) rtr;
}
else
{
/* Process an internal node (set operation node) */
SetOperationStmt *op = makeNode(SetOperationStmt);
List *lcoltypes;
List *rcoltypes;
const char *context;
context = (stmt->op == SETOP_UNION ? "UNION" :
(stmt->op == SETOP_INTERSECT ? "INTERSECT" :
"EXCEPT"));
op->op = stmt->op;
op->all = stmt->all;
/*
* Recursively transform the child nodes.
*/
op->larg = transformSetOperationTree(pstate, stmt->larg);
op->rarg = transformSetOperationTree(pstate, stmt->rarg);
/*
* Verify that the two children have the same number of non-junk
* columns, and determine the types of the merged output columns.
*/
lcoltypes = getSetColTypes(pstate, op->larg);
rcoltypes = getSetColTypes(pstate, op->rarg);
if (length(lcoltypes) != length(rcoltypes))
elog(ERROR, "Each %s query must have the same number of columns",
context);
op->colTypes = NIL;
while (lcoltypes != NIL)
{
Oid lcoltype = (Oid) lfirsti(lcoltypes);
Oid rcoltype = (Oid) lfirsti(rcoltypes);
Oid rescoltype;
rescoltype = select_common_type(makeListi2(lcoltype, rcoltype),
context);
op->colTypes = lappendi(op->colTypes, rescoltype);
lcoltypes = lnext(lcoltypes);
rcoltypes = lnext(rcoltypes);
}
return (Node *) op;
}
}
/*
* getSetColTypes
* Get output column types of an (already transformed) set-op node
*/
static List *
getSetColTypes(ParseState *pstate, Node *node)
{
if (IsA(node, RangeTblRef))
{
RangeTblRef *rtr = (RangeTblRef *) node;
RangeTblEntry *rte = rt_fetch(rtr->rtindex, pstate->p_rtable);
Query *selectQuery = rte->subquery;
List *result = NIL;
List *tl;
Assert(selectQuery != NULL);
/* Get types of non-junk columns */
foreach(tl, selectQuery->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(tl);
Resdom *resnode = tle->resdom;
if (resnode->resjunk)
continue;
result = lappendi(result, resnode->restype);
}
return result;
}
else if (IsA(node, SetOperationStmt))
{
SetOperationStmt *op = (SetOperationStmt *) node;
/* Result already computed during transformation of node */
Assert(op->colTypes != NIL);
return op->colTypes;
}
else
{
elog(ERROR, "getSetColTypes: unexpected node %d",
(int) nodeTag(node));
return NIL; /* keep compiler quiet */
}
}
/*
* transformUpdateStmt -
* transforms an update statement
*/
static Query *
transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
{
Query *qry = makeNode(Query);
Node *qual;
List *origTargetList;
List *tl;
qry->commandType = CMD_UPDATE;
pstate->p_is_update = true;
qry->resultRelation = setTargetTable(pstate, stmt->relname,
interpretInhOption(stmt->inhOpt),
true);
/*
* the FROM clause is non-standard SQL syntax. We used to be able to
* do this with REPLACE in POSTQUEL so we keep the feature.
*/
transformFromClause(pstate, stmt->fromClause);
qry->targetList = transformTargetList(pstate, stmt->targetList);
qual = transformWhereClause(pstate, stmt->whereClause);
qry->rtable = pstate->p_rtable;
qry->jointree = makeFromExpr(pstate->p_joinlist, qual);
qry->hasSubLinks = pstate->p_hasSubLinks;
qry->hasAggs = pstate->p_hasAggs;
if (pstate->p_hasAggs)
parseCheckAggregates(pstate, qry, qual);
/*
* Now we are done with SELECT-like processing, and can get on with
* transforming the target list to match the UPDATE target columns.
*/
/* Prepare to assign non-conflicting resnos to resjunk attributes */
if (pstate->p_last_resno <= pstate->p_target_relation->rd_rel->relnatts)
pstate->p_last_resno = pstate->p_target_relation->rd_rel->relnatts + 1;
/* Prepare non-junk columns for assignment to target table */
origTargetList = stmt->targetList;
foreach(tl, qry->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(tl);
Resdom *resnode = tle->resdom;
ResTarget *origTarget;
if (resnode->resjunk)
{
/*
* Resjunk nodes need no additional processing, but be sure
* they have names and resnos that do not match any target
* columns; else rewriter or planner might get confused.
*/
resnode->resname = "?resjunk?";
resnode->resno = (AttrNumber) pstate->p_last_resno++;
continue;
}
if (origTargetList == NIL)
elog(ERROR, "UPDATE target count mismatch --- internal error");
origTarget = (ResTarget *) lfirst(origTargetList);
updateTargetListEntry(pstate, tle, origTarget->name,
attnameAttNum(pstate->p_target_relation,
origTarget->name),
origTarget->indirection);
origTargetList = lnext(origTargetList);
}
if (origTargetList != NIL)
elog(ERROR, "UPDATE target count mismatch --- internal error");
return qry;
}
/*
* tranformAlterTableStmt -
* transform an Alter Table Statement
*/
static Query *
transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt)
{
CreateStmtContext cxt;
Query *qry;
/*
* The only subtypes that currently require parse transformation
* handling are 'A'dd column and Add 'C'onstraint. These largely
* re-use code from CREATE TABLE.
*/
switch (stmt->subtype)
{
case 'A':
cxt.stmtType = "ALTER TABLE";
cxt.relname = stmt->relname;
cxt.inhRelnames = NIL;
cxt.istemp = is_temp_rel_name(stmt->relname);
cxt.relOid = GetSysCacheOid(RELNAME,
PointerGetDatum(stmt->relname),
0, 0, 0);
cxt.hasoids = SearchSysCacheExists(ATTNUM,
ObjectIdGetDatum(cxt.relOid),
Int16GetDatum(ObjectIdAttributeNumber),
0, 0);
cxt.columns = NIL;
cxt.ckconstraints = NIL;
cxt.fkconstraints = NIL;
cxt.ixconstraints = NIL;
cxt.blist = NIL;
cxt.alist = NIL;
cxt.pkey = NULL;
Assert(IsA(stmt->def, ColumnDef));
transformColumnDefinition(pstate, &cxt,
(ColumnDef *) stmt->def);
transformIndexConstraints(pstate, &cxt);
transformFKConstraints(pstate, &cxt);
((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
extras_before = cxt.blist;
extras_after = cxt.alist;
break;
case 'C':
cxt.stmtType = "ALTER TABLE";
cxt.relname = stmt->relname;
cxt.inhRelnames = NIL;
cxt.istemp = is_temp_rel_name(stmt->relname);
cxt.relOid = GetSysCacheOid(RELNAME,
PointerGetDatum(stmt->relname),
0, 0, 0);
cxt.hasoids = SearchSysCacheExists(ATTNUM,
ObjectIdGetDatum(cxt.relOid),
Int16GetDatum(ObjectIdAttributeNumber),
0, 0);
cxt.columns = NIL;
cxt.ckconstraints = NIL;
cxt.fkconstraints = NIL;
cxt.ixconstraints = NIL;
cxt.blist = NIL;
cxt.alist = NIL;
cxt.pkey = NULL;
if (IsA(stmt->def, Constraint))
transformTableConstraint(pstate, &cxt,
(Constraint *) stmt->def);
else if (IsA(stmt->def, FkConstraint))
cxt.fkconstraints = lappend(cxt.fkconstraints, stmt->def);
else
elog(ERROR, "Unexpected node type in ALTER TABLE ADD CONSTRAINT");
transformIndexConstraints(pstate, &cxt);
transformFKConstraints(pstate, &cxt);
Assert(cxt.columns == NIL);
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
extras_before = cxt.blist;
extras_after = cxt.alist;
break;
default:
break;
}
qry = makeNode(Query);
qry->commandType = CMD_UTILITY;
qry->utilityStmt = (Node *) stmt;
return qry;
}
/*
* Transform uses of %TYPE in a statement.
*/
static Node *
transformTypeRefs(ParseState *pstate, Node *stmt)
{
switch (nodeTag(stmt))
{
case T_ProcedureStmt:
{
ProcedureStmt *ps = (ProcedureStmt *) stmt;
transformTypeRefsList(pstate, ps->argTypes);
transformTypeRef(pstate, (TypeName *) ps->returnType);
transformTypeRefsList(pstate, ps->withClause);
}
break;
case T_CommentStmt:
{
CommentStmt *cs = (CommentStmt *) stmt;
transformTypeRefsList(pstate, cs->objlist);
}
break;
case T_RemoveFuncStmt:
{
RemoveFuncStmt *rs = (RemoveFuncStmt *) stmt;
transformTypeRefsList(pstate, rs->args);
}
break;
case T_DefineStmt:
{
DefineStmt *ds = (DefineStmt *) stmt;
List *ele;
foreach(ele, ds->definition)
{
DefElem *de = (DefElem *) lfirst(ele);
if (de->arg != NULL
&& IsA(de->arg, TypeName))
transformTypeRef(pstate, (TypeName *) de->arg);
}
}
break;
default:
elog(ERROR, "Unsupported type %d in transformTypeRefs",
nodeTag(stmt));
break;
}
return stmt;
}
/*
* Transform uses of %TYPE in a list.
*/
static void
transformTypeRefsList(ParseState *pstate, List *l)
{
List *ele;
foreach(ele, l)
{
Node *elem = lfirst(ele);
if (elem && IsA(elem, TypeName))
transformTypeRef(pstate, (TypeName *) elem);
}
}
/*
* Transform a TypeName to not use %TYPE.
*/
static void
transformTypeRef(ParseState *pstate, TypeName *tn)
{
Attr *att;
Node *n;
Var *v;
char *tyn;
if (tn->attrname == NULL)
return;
att = makeAttr(tn->name, tn->attrname);
n = transformExpr(pstate, (Node *) att, EXPR_COLUMN_FIRST);
if (!IsA(n, Var))
elog(ERROR, "unsupported expression in %%TYPE");
v = (Var *) n;
tyn = typeidTypeName(v->vartype);
elog(NOTICE, "%s.%s%%TYPE converted to %s", tn->name, tn->attrname, tyn);
tn->name = tyn;
tn->typmod = v->vartypmod;
tn->attrname = NULL;
}
/* exported so planner can check again after rewriting, query pullup, etc */
void
CheckSelectForUpdate(Query *qry)
{
if (qry->setOperations)
elog(ERROR, "SELECT FOR UPDATE is not allowed with UNION/INTERSECT/EXCEPT");
if (qry->distinctClause != NIL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with DISTINCT clause");
if (qry->groupClause != NIL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with GROUP BY clause");
if (qry->hasAggs)
elog(ERROR, "SELECT FOR UPDATE is not allowed with AGGREGATE");
}
static void
transformForUpdate(Query *qry, List *forUpdate)
{
List *rowMarks = qry->rowMarks;
List *l;
List *rt;
Index i;
CheckSelectForUpdate(qry);
if (lfirst(forUpdate) == NULL)
{
/* all tables used in query */
i = 0;
foreach(rt, qry->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
++i;
if (rte->subquery)
{
/* FOR UPDATE of subquery is propagated to subquery's rels */
transformForUpdate(rte->subquery, makeList1(NULL));
}
else
{
if (!intMember(i, rowMarks)) /* avoid duplicates */
rowMarks = lappendi(rowMarks, i);
rte->checkForWrite = true;
}
}
}
else
{
/* just the named tables */
foreach(l, forUpdate)
{
char *relname = strVal(lfirst(l));
i = 0;
foreach(rt, qry->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
++i;
if (strcmp(rte->eref->relname, relname) == 0)
{
if (rte->subquery)
{
/* propagate to subquery */
transformForUpdate(rte->subquery, makeList1(NULL));
}
else
{
if (!intMember(i, rowMarks)) /* avoid duplicates */
rowMarks = lappendi(rowMarks, i);
rte->checkForWrite = true;
}
break;
}
}
if (rt == NIL)
elog(ERROR, "FOR UPDATE: relation \"%s\" not found in FROM clause",
relname);
}
}
qry->rowMarks = rowMarks;
}
/*
* transformFkeyCheckAttrs -
*
* Make sure that the attributes of a referenced table
* belong to a unique (or primary key) constraint.
*/
static void
transformFkeyCheckAttrs(FkConstraint *fkconstraint, Oid *pktypoid)
{
Relation pkrel;
List *indexoidlist,
*indexoidscan;
int i;
bool found = false;
/*
* Open the referenced table
*/
pkrel = heap_openr(fkconstraint->pktable_name, AccessShareLock);
/*
* Get the list of index OIDs for the table from the relcache, and
* look up each one in the pg_index syscache for each unique one, and
* then compare the attributes we were given to those defined.
*/
indexoidlist = RelationGetIndexList(pkrel);
foreach(indexoidscan, indexoidlist)
{
Oid indexoid = lfirsti(indexoidscan);
HeapTuple indexTuple;
Form_pg_index indexStruct;
found = false;
indexTuple = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(indexoid),
0, 0, 0);
if (!HeapTupleIsValid(indexTuple))
elog(ERROR, "transformFkeyCheckAttrs: index %u not found",
indexoid);
indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
if (indexStruct->indisunique)
{
for (i = 0; i < INDEX_MAX_KEYS && indexStruct->indkey[i] != 0; i++)
;
if (i == length(fkconstraint->pk_attrs))
{
/* go through the fkconstraint->pk_attrs list */
List *attrl;
int attnum = 0;
foreach(attrl, fkconstraint->pk_attrs)
{
Ident *attr = lfirst(attrl);
found = false;
for (i = 0; i < INDEX_MAX_KEYS && indexStruct->indkey[i] != 0; i++)
{
int pkattno = indexStruct->indkey[i];
if (namestrcmp(attnumAttName(pkrel, pkattno),
attr->name) == 0)
{
pktypoid[attnum++] = attnumTypeId(pkrel, pkattno);
found = true;
break;
}
}
if (!found)
break;
}
}
}
ReleaseSysCache(indexTuple);
if (found)
break;
}
if (!found)
elog(ERROR, "UNIQUE constraint matching given keys for referenced table \"%s\" not found",
fkconstraint->pktable_name);
freeList(indexoidlist);
heap_close(pkrel, AccessShareLock);
}
/*
* transformFkeyGetPrimaryKey -
*
* Try to find the primary key attributes of a referenced table if
* the column list in the REFERENCES specification was omitted.
*/
static void
transformFkeyGetPrimaryKey(FkConstraint *fkconstraint, Oid *pktypoid)
{
Relation pkrel;
List *indexoidlist,
*indexoidscan;
HeapTuple indexTuple = NULL;
Form_pg_index indexStruct = NULL;
int i;
int attnum = 0;
/*
* Open the referenced table
*/
pkrel = heap_openr(fkconstraint->pktable_name, AccessShareLock);
/*
* Get the list of index OIDs for the table from the relcache, and
* look up each one in the pg_index syscache until we find one marked
* primary key (hopefully there isn't more than one such).
*/
indexoidlist = RelationGetIndexList(pkrel);
foreach(indexoidscan, indexoidlist)
{
Oid indexoid = lfirsti(indexoidscan);
indexTuple = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(indexoid),
0, 0, 0);
if (!HeapTupleIsValid(indexTuple))
elog(ERROR, "transformFkeyGetPrimaryKey: index %u not found",
indexoid);
indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
if (indexStruct->indisprimary)
break;
ReleaseSysCache(indexTuple);
indexStruct = NULL;
}
freeList(indexoidlist);
/*
* Check that we found it
*/
if (indexStruct == NULL)
elog(ERROR, "PRIMARY KEY for referenced table \"%s\" not found",
fkconstraint->pktable_name);
/*
* Now build the list of PK attributes from the indkey definition
* using the attribute names of the PK relation descriptor
*/
for (i = 0; i < INDEX_MAX_KEYS && indexStruct->indkey[i] != 0; i++)
{
int pkattno = indexStruct->indkey[i];
Ident *pkattr = makeNode(Ident);
pkattr->name = pstrdup(NameStr(*attnumAttName(pkrel, pkattno)));
pkattr->indirection = NIL;
pkattr->isRel = false;
pktypoid[attnum++] = attnumTypeId(pkrel, pkattno);
fkconstraint->pk_attrs = lappend(fkconstraint->pk_attrs, pkattr);
}
ReleaseSysCache(indexTuple);
heap_close(pkrel, AccessShareLock);
}
/*
* relationHasPrimaryKey -
*
* See whether an existing relation has a primary key.
*/
static bool
relationHasPrimaryKey(char *relname)
{
bool result = false;
Relation rel;
List *indexoidlist,
*indexoidscan;
rel = heap_openr(relname, AccessShareLock);
/*
* Get the list of index OIDs for the table from the relcache, and
* look up each one in the pg_index syscache until we find one marked
* primary key (hopefully there isn't more than one such).
*/
indexoidlist = RelationGetIndexList(rel);
foreach(indexoidscan, indexoidlist)
{
Oid indexoid = lfirsti(indexoidscan);
HeapTuple indexTuple;
indexTuple = SearchSysCache(INDEXRELID,
ObjectIdGetDatum(indexoid),
0, 0, 0);
if (!HeapTupleIsValid(indexTuple))
elog(ERROR, "relationHasPrimaryKey: index %u not found",
indexoid);
result = ((Form_pg_index) GETSTRUCT(indexTuple))->indisprimary;
ReleaseSysCache(indexTuple);
if (result)
break;
}
freeList(indexoidlist);
heap_close(rel, AccessShareLock);
return result;
}
/*
* transformFkeyGetColType -
*
* Find a referencing column by name, and return its type OID.
* Error if it can't be found.
*/
static Oid
transformFkeyGetColType(CreateStmtContext *cxt, char *colname)
{
List *cols;
List *inher;
Oid result;
Form_pg_attribute sysatt;
/* First look for column among the newly-created columns */
foreach(cols, cxt->columns)
{
ColumnDef *col = lfirst(cols);
if (strcmp(col->colname, colname) == 0)
{
char *buff = TypeNameToInternalName(col->typename);
result = typenameTypeId(buff);
if (!OidIsValid(result))
elog(ERROR, "Unable to lookup type %s",
col->typename->name);
return result;
}
}
/* Perhaps it's a system column name */
sysatt = SystemAttributeByName(colname, cxt->hasoids);
if (sysatt)
return sysatt->atttypid;
/* Look for column among inherited columns (if CREATE TABLE case) */
foreach(inher, cxt->inhRelnames)
{
Value *inh = lfirst(inher);
Relation rel;
int count;
Assert(IsA(inh, String));
rel = heap_openr(strVal(inh), AccessShareLock);
if (rel->rd_rel->relkind != RELKIND_RELATION)
elog(ERROR, "inherited table \"%s\" is not a relation",
strVal(inh));
for (count = 0; count < rel->rd_att->natts; count++)
{
char *name = NameStr(rel->rd_att->attrs[count]->attname);
if (strcmp(name, colname) == 0)
{
result = rel->rd_att->attrs[count]->atttypid;
heap_close(rel, NoLock);
return result;
}
}
heap_close(rel, NoLock);
}
/* Look for column among existing columns (if ALTER TABLE case) */
if (OidIsValid(cxt->relOid))
{
HeapTuple atttuple;
atttuple = SearchSysCache(ATTNAME,
ObjectIdGetDatum(cxt->relOid),
PointerGetDatum(colname),
0, 0);
if (HeapTupleIsValid(atttuple))
{
result = ((Form_pg_attribute) GETSTRUCT(atttuple))->atttypid;
ReleaseSysCache(atttuple);
return result;
}
}
elog(ERROR, "%s: column \"%s\" referenced in foreign key constraint does not exist",
cxt->stmtType, colname);
return InvalidOid; /* keep compiler quiet */
}
/*
* Preprocess a list of column constraint clauses
* to attach constraint attributes to their primary constraint nodes
* and detect inconsistent/misplaced constraint attributes.
*
* NOTE: currently, attributes are only supported for FOREIGN KEY primary
* constraints, but someday they ought to be supported for other constraints.
*/
static void
transformConstraintAttrs(List *constraintList)
{
Node *lastprimarynode = NULL;
bool saw_deferrability = false;
bool saw_initially = false;
List *clist;
foreach(clist, constraintList)
{
Node *node = lfirst(clist);
if (!IsA(node, Constraint))
{
lastprimarynode = node;
/* reset flags for new primary node */
saw_deferrability = false;
saw_initially = false;
}
else
{
Constraint *con = (Constraint *) node;
switch (con->contype)
{
case CONSTR_ATTR_DEFERRABLE:
if (lastprimarynode == NULL ||
!IsA(lastprimarynode, FkConstraint))
elog(ERROR, "Misplaced DEFERRABLE clause");
if (saw_deferrability)
elog(ERROR, "Multiple DEFERRABLE/NOT DEFERRABLE clauses not allowed");
saw_deferrability = true;
((FkConstraint *) lastprimarynode)->deferrable = true;
break;
case CONSTR_ATTR_NOT_DEFERRABLE:
if (lastprimarynode == NULL ||
!IsA(lastprimarynode, FkConstraint))
elog(ERROR, "Misplaced NOT DEFERRABLE clause");
if (saw_deferrability)
elog(ERROR, "Multiple DEFERRABLE/NOT DEFERRABLE clauses not allowed");
saw_deferrability = true;
((FkConstraint *) lastprimarynode)->deferrable = false;
if (saw_initially &&
((FkConstraint *) lastprimarynode)->initdeferred)
elog(ERROR, "INITIALLY DEFERRED constraint must be DEFERRABLE");
break;
case CONSTR_ATTR_DEFERRED:
if (lastprimarynode == NULL ||
!IsA(lastprimarynode, FkConstraint))
elog(ERROR, "Misplaced INITIALLY DEFERRED clause");
if (saw_initially)
elog(ERROR, "Multiple INITIALLY IMMEDIATE/DEFERRED clauses not allowed");
saw_initially = true;
((FkConstraint *) lastprimarynode)->initdeferred = true;
/*
* If only INITIALLY DEFERRED appears, assume
* DEFERRABLE
*/
if (!saw_deferrability)
((FkConstraint *) lastprimarynode)->deferrable = true;
else if (!((FkConstraint *) lastprimarynode)->deferrable)
elog(ERROR, "INITIALLY DEFERRED constraint must be DEFERRABLE");
break;
case CONSTR_ATTR_IMMEDIATE:
if (lastprimarynode == NULL ||
!IsA(lastprimarynode, FkConstraint))
elog(ERROR, "Misplaced INITIALLY IMMEDIATE clause");
if (saw_initially)
elog(ERROR, "Multiple INITIALLY IMMEDIATE/DEFERRED clauses not allowed");
saw_initially = true;
((FkConstraint *) lastprimarynode)->initdeferred = false;
break;
default:
/* Otherwise it's not an attribute */
lastprimarynode = node;
/* reset flags for new primary node */
saw_deferrability = false;
saw_initially = false;
break;
}
}
}
}
/* Build a FromExpr node */
static FromExpr *
makeFromExpr(List *fromlist, Node *quals)
{
FromExpr *f = makeNode(FromExpr);
f->fromlist = fromlist;
f->quals = quals;
return f;
}
/*
* Special handling of type definition for a column
*/
static void
transformColumnType(ParseState *pstate, ColumnDef *column)
{
TypeName *typename = column->typename;
Type ctype = typenameType(typename->name);
/*
* If the column doesn't have an explicitly specified typmod, check to
* see if we want to insert a default length.
*
* Note that we deliberately do NOT look at array or set information
* here; "numeric[]" needs the same default typmod as "numeric".
*/
if (typename->typmod == -1)
{
switch (typeTypeId(ctype))
{
case BPCHAROID:
/* "char" -> "char(1)" */
typename->typmod = VARHDRSZ + 1;
break;
case NUMERICOID:
typename->typmod = VARHDRSZ +
((NUMERIC_DEFAULT_PRECISION << 16) | NUMERIC_DEFAULT_SCALE);
break;
case BITOID:
/* 'bit' -> 'bit(1)' */
typename->typmod = 1;
break;
}
}
/*
* Is this the name of a complex type? If so, implement it as a set.
*
* XXX this is a hangover from ancient Berkeley code that probably
* doesn't work anymore anyway.
*/
if (typeTypeRelid(ctype) != InvalidOid)
{
/*
* (Eventually add in here that the set can only contain one
* element.)
*/
typename->setof = true;
}
ReleaseSysCache(ctype);
}
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