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2007 lines
48 KiB
C
2007 lines
48 KiB
C
/*
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* dblink.c
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*
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* Functions returning results from a remote database
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*
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* Joe Conway <mail@joeconway.com>
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*
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* Copyright (c) 2001, 2002 by PostgreSQL Global Development Group
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* ALL RIGHTS RESERVED;
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*
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* Permission to use, copy, modify, and distribute this software and its
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* documentation for any purpose, without fee, and without a written agreement
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* is hereby granted, provided that the above copyright notice and this
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* paragraph and the following two paragraphs appear in all copies.
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*
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* IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
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* LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
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* DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*
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*/
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#include "postgres.h"
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#include "libpq-fe.h"
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#include "fmgr.h"
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#include "funcapi.h"
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#include "access/tupdesc.h"
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#include "access/heapam.h"
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#include "catalog/catname.h"
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#include "catalog/namespace.h"
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#include "catalog/pg_index.h"
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#include "catalog/pg_type.h"
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#include "executor/executor.h"
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#include "executor/spi.h"
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#include "lib/stringinfo.h"
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#include "nodes/nodes.h"
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#include "nodes/execnodes.h"
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#include "nodes/pg_list.h"
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#include "parser/parse_type.h"
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#include "tcop/tcopprot.h"
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#include "utils/builtins.h"
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#include "utils/fmgroids.h"
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#include "utils/array.h"
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#include "utils/lsyscache.h"
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#include "utils/syscache.h"
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#include "dblink.h"
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/*
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* Internal declarations
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*/
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static dblink_results *init_dblink_results(MemoryContext fn_mcxt);
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static char **get_pkey_attnames(Oid relid, int16 *numatts);
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static char *get_sql_insert(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals);
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static char *get_sql_delete(Oid relid, int16 *pkattnums, int16 pknumatts, char **tgt_pkattvals);
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static char *get_sql_update(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals);
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static char *quote_literal_cstr(char *rawstr);
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static char *quote_ident_cstr(char *rawstr);
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static int16 get_attnum_pk_pos(int16 *pkattnums, int16 pknumatts, int16 key);
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static HeapTuple get_tuple_of_interest(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals);
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static Oid get_relid_from_relname(text *relname_text);
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static dblink_results *get_res_ptr(int32 res_id_index);
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static void append_res_ptr(dblink_results * results);
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static void remove_res_ptr(dblink_results * results);
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static TupleDesc pgresultGetTupleDesc(PGresult *res);
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/* Global */
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List *res_id = NIL;
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int res_id_index = 0;
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PGconn *persistent_conn = NULL;
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#define GET_TEXT(cstrp) DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(cstrp)))
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#define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
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#define xpfree(var_) \
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do { \
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if (var_ != NULL) \
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{ \
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pfree(var_); \
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var_ = NULL; \
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} \
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} while (0)
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/*
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* Create a persistent connection to another database
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*/
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PG_FUNCTION_INFO_V1(dblink_connect);
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Datum
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dblink_connect(PG_FUNCTION_ARGS)
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{
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char *connstr = GET_STR(PG_GETARG_TEXT_P(0));
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char *msg;
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text *result_text;
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MemoryContext oldcontext;
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if (persistent_conn != NULL)
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PQfinish(persistent_conn);
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oldcontext = MemoryContextSwitchTo(TopMemoryContext);
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persistent_conn = PQconnectdb(connstr);
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MemoryContextSwitchTo(oldcontext);
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if (PQstatus(persistent_conn) == CONNECTION_BAD)
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{
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msg = pstrdup(PQerrorMessage(persistent_conn));
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PQfinish(persistent_conn);
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persistent_conn = NULL;
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elog(ERROR, "dblink_connect: connection error: %s", msg);
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}
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result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum("OK")));
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PG_RETURN_TEXT_P(result_text);
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}
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/*
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* Clear a persistent connection to another database
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*/
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PG_FUNCTION_INFO_V1(dblink_disconnect);
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Datum
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dblink_disconnect(PG_FUNCTION_ARGS)
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{
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text *result_text;
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if (persistent_conn != NULL)
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PQfinish(persistent_conn);
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persistent_conn = NULL;
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result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum("OK")));
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PG_RETURN_TEXT_P(result_text);
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}
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/*
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* opens a cursor using a persistent connection
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*/
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PG_FUNCTION_INFO_V1(dblink_open);
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Datum
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dblink_open(PG_FUNCTION_ARGS)
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{
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char *msg;
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PGresult *res = NULL;
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PGconn *conn = NULL;
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text *result_text;
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char *curname = GET_STR(PG_GETARG_TEXT_P(0));
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char *sql = GET_STR(PG_GETARG_TEXT_P(1));
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StringInfo str = makeStringInfo();
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if (persistent_conn != NULL)
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conn = persistent_conn;
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else
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elog(ERROR, "dblink_open: no connection available");
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res = PQexec(conn, "BEGIN");
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if (PQresultStatus(res) != PGRES_COMMAND_OK)
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQclear(res);
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PQfinish(conn);
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persistent_conn = NULL;
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elog(ERROR, "dblink_open: begin error: %s", msg);
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}
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PQclear(res);
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appendStringInfo(str, "DECLARE %s CURSOR FOR %s", quote_ident_cstr(curname), sql);
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res = PQexec(conn, str->data);
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if (!res ||
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(PQresultStatus(res) != PGRES_COMMAND_OK &&
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PQresultStatus(res) != PGRES_TUPLES_OK))
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQclear(res);
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PQfinish(conn);
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persistent_conn = NULL;
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elog(ERROR, "dblink: sql error: %s", msg);
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}
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result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum("OK")));
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PG_RETURN_TEXT_P(result_text);
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}
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/*
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* closes a cursor
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*/
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PG_FUNCTION_INFO_V1(dblink_close);
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Datum
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dblink_close(PG_FUNCTION_ARGS)
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{
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PGconn *conn = NULL;
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PGresult *res = NULL;
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char *curname = GET_STR(PG_GETARG_TEXT_P(0));
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StringInfo str = makeStringInfo();
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text *result_text;
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char *msg;
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if (persistent_conn != NULL)
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conn = persistent_conn;
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else
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elog(ERROR, "dblink_close: no connection available");
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appendStringInfo(str, "CLOSE %s", quote_ident_cstr(curname));
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/* close the cursor */
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res = PQexec(conn, str->data);
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if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQclear(res);
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PQfinish(persistent_conn);
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persistent_conn = NULL;
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elog(ERROR, "dblink_close: sql error: %s", msg);
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}
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PQclear(res);
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/* commit the transaction */
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res = PQexec(conn, "COMMIT");
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if (PQresultStatus(res) != PGRES_COMMAND_OK)
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQclear(res);
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PQfinish(persistent_conn);
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persistent_conn = NULL;
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elog(ERROR, "dblink_close: commit error: %s", msg);
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}
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PQclear(res);
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result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum("OK")));
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PG_RETURN_TEXT_P(result_text);
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}
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/*
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* Fetch results from an open cursor
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*/
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PG_FUNCTION_INFO_V1(dblink_fetch);
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Datum
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dblink_fetch(PG_FUNCTION_ARGS)
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{
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FuncCallContext *funcctx;
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TupleDesc tupdesc = NULL;
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int call_cntr;
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int max_calls;
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TupleTableSlot *slot;
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AttInMetadata *attinmeta;
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char *msg;
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PGresult *res = NULL;
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MemoryContext oldcontext;
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/* stuff done only on the first call of the function */
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if (SRF_IS_FIRSTCALL())
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{
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Oid functypeid;
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char functyptype;
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Oid funcid = fcinfo->flinfo->fn_oid;
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PGconn *conn = NULL;
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StringInfo str = makeStringInfo();
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char *curname = GET_STR(PG_GETARG_TEXT_P(0));
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int howmany = PG_GETARG_INT32(1);
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/* create a function context for cross-call persistence */
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funcctx = SRF_FIRSTCALL_INIT();
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/*
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* switch to memory context appropriate for multiple function
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* calls
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*/
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oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
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if (persistent_conn != NULL)
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conn = persistent_conn;
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else
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elog(ERROR, "dblink_fetch: no connection available");
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appendStringInfo(str, "FETCH %d FROM %s", howmany, quote_ident_cstr(curname));
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res = PQexec(conn, str->data);
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if (!res ||
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(PQresultStatus(res) != PGRES_COMMAND_OK &&
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PQresultStatus(res) != PGRES_TUPLES_OK))
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQclear(res);
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PQfinish(persistent_conn);
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persistent_conn = NULL;
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elog(ERROR, "dblink_fetch: sql error: %s", msg);
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}
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else if (PQresultStatus(res) == PGRES_COMMAND_OK)
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{
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/* cursor does not exist - closed already or bad name */
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PQclear(res);
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elog(ERROR, "dblink_fetch: cursor %s does not exist", quote_ident_cstr(curname));
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}
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funcctx->max_calls = PQntuples(res);
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/* got results, keep track of them */
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funcctx->user_fctx = res;
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/* fast track when no results */
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if (funcctx->max_calls < 1)
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SRF_RETURN_DONE(funcctx);
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/* check typtype to see if we have a predetermined return type */
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functypeid = get_func_rettype(funcid);
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functyptype = get_typtype(functypeid);
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if (functyptype == 'c')
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tupdesc = TypeGetTupleDesc(functypeid, NIL);
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else if (functyptype == 'p' && functypeid == RECORDOID)
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tupdesc = pgresultGetTupleDesc(res);
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else if (functyptype == 'b')
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elog(ERROR, "dblink_fetch: invalid kind of return type specified for function");
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else
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elog(ERROR, "dblink_fetch: unknown kind of return type specified for function");
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/* store needed metadata for subsequent calls */
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slot = TupleDescGetSlot(tupdesc);
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funcctx->slot = slot;
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attinmeta = TupleDescGetAttInMetadata(tupdesc);
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funcctx->attinmeta = attinmeta;
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MemoryContextSwitchTo(oldcontext);
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}
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/* stuff done on every call of the function */
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funcctx = SRF_PERCALL_SETUP();
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/*
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* initialize per-call variables
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*/
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call_cntr = funcctx->call_cntr;
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max_calls = funcctx->max_calls;
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slot = funcctx->slot;
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res = (PGresult *) funcctx->user_fctx;
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attinmeta = funcctx->attinmeta;
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tupdesc = attinmeta->tupdesc;
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if (call_cntr < max_calls) /* do when there is more left to send */
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{
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char **values;
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HeapTuple tuple;
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Datum result;
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int i;
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int nfields = PQnfields(res);
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values = (char **) palloc(nfields * sizeof(char *));
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for (i = 0; i < nfields; i++)
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{
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if (PQgetisnull(res, call_cntr, i) == 0)
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values[i] = PQgetvalue(res, call_cntr, i);
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else
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values[i] = NULL;
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}
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/* build the tuple */
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tuple = BuildTupleFromCStrings(attinmeta, values);
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/* make the tuple into a datum */
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result = TupleGetDatum(slot, tuple);
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SRF_RETURN_NEXT(funcctx, result);
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}
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else
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/* do when there is no more left */
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{
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PQclear(res);
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SRF_RETURN_DONE(funcctx);
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}
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}
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/*
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* Note: this is the new preferred version of dblink
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*/
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PG_FUNCTION_INFO_V1(dblink_record);
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Datum
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dblink_record(PG_FUNCTION_ARGS)
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{
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FuncCallContext *funcctx;
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TupleDesc tupdesc = NULL;
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int call_cntr;
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int max_calls;
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TupleTableSlot *slot;
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AttInMetadata *attinmeta;
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char *msg;
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PGresult *res = NULL;
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bool is_sql_cmd = false;
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char *sql_cmd_status = NULL;
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MemoryContext oldcontext;
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/* stuff done only on the first call of the function */
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if (SRF_IS_FIRSTCALL())
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{
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Oid functypeid;
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char functyptype;
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Oid funcid = fcinfo->flinfo->fn_oid;
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PGconn *conn = NULL;
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char *connstr = NULL;
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char *sql = NULL;
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/* create a function context for cross-call persistence */
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funcctx = SRF_FIRSTCALL_INIT();
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/*
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* switch to memory context appropriate for multiple function
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* calls
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*/
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oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
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if (fcinfo->nargs == 2)
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{
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connstr = GET_STR(PG_GETARG_TEXT_P(0));
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sql = GET_STR(PG_GETARG_TEXT_P(1));
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conn = PQconnectdb(connstr);
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if (PQstatus(conn) == CONNECTION_BAD)
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQfinish(conn);
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elog(ERROR, "dblink: connection error: %s", msg);
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}
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}
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else if (fcinfo->nargs == 1)
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{
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sql = GET_STR(PG_GETARG_TEXT_P(0));
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if (persistent_conn != NULL)
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conn = persistent_conn;
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else
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elog(ERROR, "dblink: no connection available");
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}
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else
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elog(ERROR, "dblink: wrong number of arguments");
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res = PQexec(conn, sql);
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if (!res || (PQresultStatus(res) != PGRES_COMMAND_OK && PQresultStatus(res) != PGRES_TUPLES_OK))
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{
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msg = pstrdup(PQerrorMessage(conn));
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PQclear(res);
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PQfinish(conn);
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if (fcinfo->nargs == 1)
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persistent_conn = NULL;
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elog(ERROR, "dblink: sql error: %s", msg);
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}
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else
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{
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if (PQresultStatus(res) == PGRES_COMMAND_OK)
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{
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is_sql_cmd = true;
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/* need a tuple descriptor representing one TEXT column */
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tupdesc = CreateTemplateTupleDesc(1, false);
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TupleDescInitEntry(tupdesc, (AttrNumber) 1, "status",
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TEXTOID, -1, 0, false);
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/*
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* and save a copy of the command status string to return
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* as our result tuple
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*/
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sql_cmd_status = PQcmdStatus(res);
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funcctx->max_calls = 1;
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}
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else
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funcctx->max_calls = PQntuples(res);
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/* got results, keep track of them */
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funcctx->user_fctx = res;
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/* if needed, close the connection to the database and cleanup */
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if (fcinfo->nargs == 2)
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PQfinish(conn);
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}
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/* fast track when no results */
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if (funcctx->max_calls < 1)
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SRF_RETURN_DONE(funcctx);
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/* check typtype to see if we have a predetermined return type */
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functypeid = get_func_rettype(funcid);
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functyptype = get_typtype(functypeid);
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if (!is_sql_cmd)
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{
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if (functyptype == 'c')
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tupdesc = TypeGetTupleDesc(functypeid, NIL);
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else if (functyptype == 'p' && functypeid == RECORDOID)
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tupdesc = pgresultGetTupleDesc(res);
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else if (functyptype == 'b')
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elog(ERROR, "Invalid kind of return type specified for function");
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else
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elog(ERROR, "Unknown kind of return type specified for function");
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}
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/* store needed metadata for subsequent calls */
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|
slot = TupleDescGetSlot(tupdesc);
|
|
funcctx->slot = slot;
|
|
attinmeta = TupleDescGetAttInMetadata(tupdesc);
|
|
funcctx->attinmeta = attinmeta;
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
|
|
/* stuff done on every call of the function */
|
|
funcctx = SRF_PERCALL_SETUP();
|
|
|
|
/*
|
|
* initialize per-call variables
|
|
*/
|
|
call_cntr = funcctx->call_cntr;
|
|
max_calls = funcctx->max_calls;
|
|
|
|
slot = funcctx->slot;
|
|
|
|
res = (PGresult *) funcctx->user_fctx;
|
|
attinmeta = funcctx->attinmeta;
|
|
tupdesc = attinmeta->tupdesc;
|
|
|
|
if (call_cntr < max_calls) /* do when there is more left to send */
|
|
{
|
|
char **values;
|
|
HeapTuple tuple;
|
|
Datum result;
|
|
|
|
if (!is_sql_cmd)
|
|
{
|
|
int i;
|
|
int nfields = PQnfields(res);
|
|
|
|
values = (char **) palloc(nfields * sizeof(char *));
|
|
for (i = 0; i < nfields; i++)
|
|
{
|
|
if (PQgetisnull(res, call_cntr, i) == 0)
|
|
values[i] = PQgetvalue(res, call_cntr, i);
|
|
else
|
|
values[i] = NULL;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
values = (char **) palloc(1 * sizeof(char *));
|
|
values[0] = sql_cmd_status;
|
|
}
|
|
|
|
/* build the tuple */
|
|
tuple = BuildTupleFromCStrings(attinmeta, values);
|
|
|
|
/* make the tuple into a datum */
|
|
result = TupleGetDatum(slot, tuple);
|
|
|
|
SRF_RETURN_NEXT(funcctx, result);
|
|
}
|
|
else
|
|
/* do when there is no more left */
|
|
{
|
|
PQclear(res);
|
|
SRF_RETURN_DONE(funcctx);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Execute an SQL non-SELECT command
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_exec);
|
|
Datum
|
|
dblink_exec(PG_FUNCTION_ARGS)
|
|
{
|
|
char *msg;
|
|
PGresult *res = NULL;
|
|
char *sql_cmd_status = NULL;
|
|
TupleDesc tupdesc = NULL;
|
|
text *result_text;
|
|
PGconn *conn = NULL;
|
|
char *connstr = NULL;
|
|
char *sql = NULL;
|
|
|
|
if (fcinfo->nargs == 2)
|
|
{
|
|
connstr = GET_STR(PG_GETARG_TEXT_P(0));
|
|
sql = GET_STR(PG_GETARG_TEXT_P(1));
|
|
|
|
conn = PQconnectdb(connstr);
|
|
if (PQstatus(conn) == CONNECTION_BAD)
|
|
{
|
|
msg = pstrdup(PQerrorMessage(conn));
|
|
PQfinish(conn);
|
|
elog(ERROR, "dblink_exec: connection error: %s", msg);
|
|
}
|
|
}
|
|
else if (fcinfo->nargs == 1)
|
|
{
|
|
sql = GET_STR(PG_GETARG_TEXT_P(0));
|
|
|
|
if (persistent_conn != NULL)
|
|
conn = persistent_conn;
|
|
else
|
|
elog(ERROR, "dblink_exec: no connection available");
|
|
}
|
|
else
|
|
elog(ERROR, "dblink_exec: wrong number of arguments");
|
|
|
|
|
|
res = PQexec(conn, sql);
|
|
if (!res || (PQresultStatus(res) != PGRES_COMMAND_OK && PQresultStatus(res) != PGRES_TUPLES_OK))
|
|
{
|
|
msg = pstrdup(PQerrorMessage(conn));
|
|
PQclear(res);
|
|
PQfinish(conn);
|
|
if (fcinfo->nargs == 1)
|
|
persistent_conn = NULL;
|
|
|
|
elog(ERROR, "dblink_exec: sql error: %s", msg);
|
|
}
|
|
else
|
|
{
|
|
if (PQresultStatus(res) == PGRES_COMMAND_OK)
|
|
{
|
|
/* need a tuple descriptor representing one TEXT column */
|
|
tupdesc = CreateTemplateTupleDesc(1, false);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "status",
|
|
TEXTOID, -1, 0, false);
|
|
|
|
/*
|
|
* and save a copy of the command status string to return as
|
|
* our result tuple
|
|
*/
|
|
sql_cmd_status = PQcmdStatus(res);
|
|
}
|
|
else
|
|
elog(ERROR, "dblink_exec: queries returning results not allowed");
|
|
}
|
|
PQclear(res);
|
|
|
|
/* if needed, close the connection to the database and cleanup */
|
|
if (fcinfo->nargs == 2)
|
|
PQfinish(conn);
|
|
|
|
result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(sql_cmd_status)));
|
|
PG_RETURN_TEXT_P(result_text);
|
|
}
|
|
|
|
/*
|
|
* Note: this original version of dblink is DEPRECATED;
|
|
* it *will* be removed in favor of the new version on next release
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink);
|
|
Datum
|
|
dblink(PG_FUNCTION_ARGS)
|
|
{
|
|
PGconn *conn = NULL;
|
|
PGresult *res = NULL;
|
|
dblink_results *results;
|
|
char *optstr;
|
|
char *sqlstatement;
|
|
char *execstatement;
|
|
char *msg;
|
|
int ntuples = 0;
|
|
ReturnSetInfo *rsi;
|
|
|
|
if (fcinfo->resultinfo == NULL || !IsA(fcinfo->resultinfo, ReturnSetInfo))
|
|
elog(ERROR, "dblink: function called in context that does not accept a set result");
|
|
|
|
optstr = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(PG_GETARG_TEXT_P(0))));
|
|
sqlstatement = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(PG_GETARG_TEXT_P(1))));
|
|
|
|
if (fcinfo->flinfo->fn_extra == NULL)
|
|
{
|
|
|
|
conn = PQconnectdb(optstr);
|
|
if (PQstatus(conn) == CONNECTION_BAD)
|
|
{
|
|
msg = pstrdup(PQerrorMessage(conn));
|
|
PQfinish(conn);
|
|
elog(ERROR, "dblink: connection error: %s", msg);
|
|
}
|
|
|
|
execstatement = (char *) palloc(strlen(sqlstatement) + 1);
|
|
if (execstatement != NULL)
|
|
{
|
|
strcpy(execstatement, sqlstatement);
|
|
strcat(execstatement, "\0");
|
|
}
|
|
else
|
|
elog(ERROR, "dblink: insufficient memory");
|
|
|
|
res = PQexec(conn, execstatement);
|
|
if (!res || (PQresultStatus(res) != PGRES_COMMAND_OK && PQresultStatus(res) != PGRES_TUPLES_OK))
|
|
{
|
|
msg = pstrdup(PQerrorMessage(conn));
|
|
PQclear(res);
|
|
PQfinish(conn);
|
|
elog(ERROR, "dblink: sql error: %s", msg);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* got results, start fetching them
|
|
*/
|
|
ntuples = PQntuples(res);
|
|
|
|
/*
|
|
* increment resource index
|
|
*/
|
|
res_id_index++;
|
|
|
|
results = init_dblink_results(fcinfo->flinfo->fn_mcxt);
|
|
results->tup_num = 0;
|
|
results->res_id_index = res_id_index;
|
|
results->res = res;
|
|
|
|
/*
|
|
* Append node to res_id to hold pointer to results. Needed by
|
|
* dblink_tok to access the data
|
|
*/
|
|
append_res_ptr(results);
|
|
|
|
/*
|
|
* save pointer to results for the next function manager call
|
|
*/
|
|
fcinfo->flinfo->fn_extra = (void *) results;
|
|
|
|
/* close the connection to the database and cleanup */
|
|
PQfinish(conn);
|
|
|
|
rsi = (ReturnSetInfo *) fcinfo->resultinfo;
|
|
rsi->isDone = ExprMultipleResult;
|
|
|
|
PG_RETURN_INT32(res_id_index);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* check for more results
|
|
*/
|
|
results = fcinfo->flinfo->fn_extra;
|
|
|
|
results->tup_num++;
|
|
res_id_index = results->res_id_index;
|
|
ntuples = PQntuples(results->res);
|
|
|
|
if (results->tup_num < ntuples)
|
|
{
|
|
/*
|
|
* fetch them if available
|
|
*/
|
|
|
|
rsi = (ReturnSetInfo *) fcinfo->resultinfo;
|
|
rsi->isDone = ExprMultipleResult;
|
|
|
|
PG_RETURN_INT32(res_id_index);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* or if no more, clean things up
|
|
*/
|
|
results = fcinfo->flinfo->fn_extra;
|
|
|
|
remove_res_ptr(results);
|
|
PQclear(results->res);
|
|
pfree(results);
|
|
fcinfo->flinfo->fn_extra = NULL;
|
|
|
|
rsi = (ReturnSetInfo *) fcinfo->resultinfo;
|
|
rsi->isDone = ExprEndResult;
|
|
|
|
PG_RETURN_NULL();
|
|
}
|
|
}
|
|
PG_RETURN_NULL();
|
|
}
|
|
|
|
/*
|
|
* Note: dblink_tok is DEPRECATED;
|
|
* it *will* be removed in favor of the new version on next release
|
|
*
|
|
* dblink_tok
|
|
* parse dblink output string
|
|
* return fldnum item (0 based)
|
|
* based on provided field separator
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_tok);
|
|
Datum
|
|
dblink_tok(PG_FUNCTION_ARGS)
|
|
{
|
|
dblink_results *results;
|
|
int fldnum;
|
|
text *result_text;
|
|
char *result;
|
|
int nfields = 0;
|
|
int text_len = 0;
|
|
|
|
results = get_res_ptr(PG_GETARG_INT32(0));
|
|
if (results == NULL)
|
|
{
|
|
if (res_id != NIL)
|
|
{
|
|
freeList(res_id);
|
|
res_id = NIL;
|
|
res_id_index = 0;
|
|
}
|
|
|
|
elog(ERROR, "dblink_tok: function called with invalid resource id");
|
|
}
|
|
|
|
fldnum = PG_GETARG_INT32(1);
|
|
if (fldnum < 0)
|
|
elog(ERROR, "dblink_tok: field number < 0 not permitted");
|
|
|
|
nfields = PQnfields(results->res);
|
|
if (fldnum > (nfields - 1))
|
|
elog(ERROR, "dblink_tok: field number %d does not exist", fldnum);
|
|
|
|
if (PQgetisnull(results->res, results->tup_num, fldnum) == 1)
|
|
PG_RETURN_NULL();
|
|
else
|
|
{
|
|
text_len = PQgetlength(results->res, results->tup_num, fldnum);
|
|
|
|
result = (char *) palloc(text_len + 1);
|
|
|
|
if (result != NULL)
|
|
{
|
|
strcpy(result, PQgetvalue(results->res, results->tup_num, fldnum));
|
|
strcat(result, "\0");
|
|
}
|
|
else
|
|
elog(ERROR, "dblink: insufficient memory");
|
|
|
|
result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(result)));
|
|
|
|
PG_RETURN_TEXT_P(result_text);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* dblink_get_pkey
|
|
*
|
|
* Return list of primary key fields for the supplied relation,
|
|
* or NULL if none exists.
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_get_pkey);
|
|
Datum
|
|
dblink_get_pkey(PG_FUNCTION_ARGS)
|
|
{
|
|
int16 numatts;
|
|
Oid relid;
|
|
char **results;
|
|
FuncCallContext *funcctx;
|
|
int32 call_cntr;
|
|
int32 max_calls;
|
|
TupleTableSlot *slot;
|
|
AttInMetadata *attinmeta;
|
|
MemoryContext oldcontext;
|
|
|
|
/* stuff done only on the first call of the function */
|
|
if (SRF_IS_FIRSTCALL())
|
|
{
|
|
TupleDesc tupdesc = NULL;
|
|
|
|
/* create a function context for cross-call persistence */
|
|
funcctx = SRF_FIRSTCALL_INIT();
|
|
|
|
/*
|
|
* switch to memory context appropriate for multiple function
|
|
* calls
|
|
*/
|
|
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
|
|
|
|
/* convert relname to rel Oid */
|
|
relid = get_relid_from_relname(PG_GETARG_TEXT_P(0));
|
|
if (!OidIsValid(relid))
|
|
elog(ERROR, "dblink_get_pkey: relation does not exist");
|
|
|
|
/*
|
|
* need a tuple descriptor representing one INT and one TEXT
|
|
* column
|
|
*/
|
|
tupdesc = CreateTemplateTupleDesc(2, false);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "position",
|
|
INT4OID, -1, 0, false);
|
|
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "colname",
|
|
TEXTOID, -1, 0, false);
|
|
|
|
/* allocate a slot for a tuple with this tupdesc */
|
|
slot = TupleDescGetSlot(tupdesc);
|
|
|
|
/* assign slot to function context */
|
|
funcctx->slot = slot;
|
|
|
|
/*
|
|
* Generate attribute metadata needed later to produce tuples from
|
|
* raw C strings
|
|
*/
|
|
attinmeta = TupleDescGetAttInMetadata(tupdesc);
|
|
funcctx->attinmeta = attinmeta;
|
|
|
|
/* get an array of attnums */
|
|
results = get_pkey_attnames(relid, &numatts);
|
|
|
|
if ((results != NULL) && (numatts > 0))
|
|
{
|
|
funcctx->max_calls = numatts;
|
|
|
|
/* got results, keep track of them */
|
|
funcctx->user_fctx = results;
|
|
}
|
|
else
|
|
/* fast track when no results */
|
|
SRF_RETURN_DONE(funcctx);
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
}
|
|
|
|
/* stuff done on every call of the function */
|
|
funcctx = SRF_PERCALL_SETUP();
|
|
|
|
/*
|
|
* initialize per-call variables
|
|
*/
|
|
call_cntr = funcctx->call_cntr;
|
|
max_calls = funcctx->max_calls;
|
|
|
|
slot = funcctx->slot;
|
|
|
|
results = (char **) funcctx->user_fctx;
|
|
attinmeta = funcctx->attinmeta;
|
|
|
|
if (call_cntr < max_calls) /* do when there is more left to send */
|
|
{
|
|
char **values;
|
|
HeapTuple tuple;
|
|
Datum result;
|
|
|
|
values = (char **) palloc(2 * sizeof(char *));
|
|
values[0] = (char *) palloc(12); /* sign, 10 digits, '\0' */
|
|
|
|
sprintf(values[0], "%d", call_cntr + 1);
|
|
|
|
values[1] = results[call_cntr];
|
|
|
|
/* build the tuple */
|
|
tuple = BuildTupleFromCStrings(attinmeta, values);
|
|
|
|
/* make the tuple into a datum */
|
|
result = TupleGetDatum(slot, tuple);
|
|
|
|
SRF_RETURN_NEXT(funcctx, result);
|
|
}
|
|
else
|
|
/* do when there is no more left */
|
|
SRF_RETURN_DONE(funcctx);
|
|
}
|
|
|
|
/*
|
|
* Note: dblink_last_oid is DEPRECATED;
|
|
* it *will* be removed on next release
|
|
*
|
|
* dblink_last_oid
|
|
* return last inserted oid
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_last_oid);
|
|
Datum
|
|
dblink_last_oid(PG_FUNCTION_ARGS)
|
|
{
|
|
dblink_results *results;
|
|
|
|
results = get_res_ptr(PG_GETARG_INT32(0));
|
|
if (results == NULL)
|
|
{
|
|
if (res_id != NIL)
|
|
{
|
|
freeList(res_id);
|
|
res_id = NIL;
|
|
res_id_index = 0;
|
|
}
|
|
|
|
elog(ERROR, "dblink_tok: function called with invalid resource id");
|
|
}
|
|
|
|
PG_RETURN_OID(PQoidValue(results->res));
|
|
}
|
|
|
|
|
|
#ifndef SHRT_MAX
|
|
#define SHRT_MAX (0x7FFF)
|
|
#endif
|
|
/*
|
|
* dblink_build_sql_insert
|
|
*
|
|
* Used to generate an SQL insert statement
|
|
* based on an existing tuple in a local relation.
|
|
* This is useful for selectively replicating data
|
|
* to another server via dblink.
|
|
*
|
|
* API:
|
|
* <relname> - name of local table of interest
|
|
* <pkattnums> - an int2vector of attnums which will be used
|
|
* to identify the local tuple of interest
|
|
* <pknumatts> - number of attnums in pkattnums
|
|
* <src_pkattvals_arry> - text array of key values which will be used
|
|
* to identify the local tuple of interest
|
|
* <tgt_pkattvals_arry> - text array of key values which will be used
|
|
* to build the string for execution remotely. These are substituted
|
|
* for their counterparts in src_pkattvals_arry
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_build_sql_insert);
|
|
Datum
|
|
dblink_build_sql_insert(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid relid;
|
|
text *relname_text;
|
|
int16 *pkattnums;
|
|
int pknumatts_tmp;
|
|
int16 pknumatts = 0;
|
|
char **src_pkattvals;
|
|
char **tgt_pkattvals;
|
|
ArrayType *src_pkattvals_arry;
|
|
ArrayType *tgt_pkattvals_arry;
|
|
int src_ndim;
|
|
int *src_dim;
|
|
int src_nitems;
|
|
int tgt_ndim;
|
|
int *tgt_dim;
|
|
int tgt_nitems;
|
|
int i;
|
|
char *ptr;
|
|
char *sql;
|
|
text *sql_text;
|
|
int16 typlen;
|
|
bool typbyval;
|
|
char typalign;
|
|
|
|
relname_text = PG_GETARG_TEXT_P(0);
|
|
|
|
/*
|
|
* Convert relname to rel OID.
|
|
*/
|
|
relid = get_relid_from_relname(relname_text);
|
|
if (!OidIsValid(relid))
|
|
elog(ERROR, "dblink_build_sql_insert: relation does not exist");
|
|
|
|
pkattnums = (int16 *) PG_GETARG_POINTER(1);
|
|
pknumatts_tmp = PG_GETARG_INT32(2);
|
|
if (pknumatts_tmp <= SHRT_MAX)
|
|
pknumatts = pknumatts_tmp;
|
|
else
|
|
elog(ERROR, "Bad input value for pknumatts; too large");
|
|
|
|
/*
|
|
* There should be at least one key attribute
|
|
*/
|
|
if (pknumatts == 0)
|
|
elog(ERROR, "dblink_build_sql_insert: number of key attributes must be > 0.");
|
|
|
|
src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
|
|
tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
|
|
|
|
/*
|
|
* Source array is made up of key values that will be used to locate
|
|
* the tuple of interest from the local system.
|
|
*/
|
|
src_ndim = ARR_NDIM(src_pkattvals_arry);
|
|
src_dim = ARR_DIMS(src_pkattvals_arry);
|
|
src_nitems = ArrayGetNItems(src_ndim, src_dim);
|
|
|
|
/*
|
|
* There should be one source array key value for each key attnum
|
|
*/
|
|
if (src_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: source key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input source array
|
|
*/
|
|
Assert(ARR_ELEMTYPE(src_pkattvals_arry) == TEXTOID);
|
|
get_typlenbyvalalign(ARR_ELEMTYPE(src_pkattvals_arry),
|
|
&typlen, &typbyval, &typalign);
|
|
|
|
src_pkattvals = (char **) palloc(src_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(src_pkattvals_arry);
|
|
for (i = 0; i < src_nitems; i++)
|
|
{
|
|
src_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr = att_addlength(ptr, typlen, PointerGetDatum(ptr));
|
|
ptr = (char *) att_align(ptr, typalign);
|
|
}
|
|
|
|
/*
|
|
* Target array is made up of key values that will be used to build
|
|
* the SQL string for use on the remote system.
|
|
*/
|
|
tgt_ndim = ARR_NDIM(tgt_pkattvals_arry);
|
|
tgt_dim = ARR_DIMS(tgt_pkattvals_arry);
|
|
tgt_nitems = ArrayGetNItems(tgt_ndim, tgt_dim);
|
|
|
|
/*
|
|
* There should be one target array key value for each key attnum
|
|
*/
|
|
if (tgt_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: target key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input target array
|
|
*/
|
|
Assert(ARR_ELEMTYPE(tgt_pkattvals_arry) == TEXTOID);
|
|
get_typlenbyvalalign(ARR_ELEMTYPE(tgt_pkattvals_arry),
|
|
&typlen, &typbyval, &typalign);
|
|
|
|
tgt_pkattvals = (char **) palloc(tgt_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(tgt_pkattvals_arry);
|
|
for (i = 0; i < tgt_nitems; i++)
|
|
{
|
|
tgt_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr = att_addlength(ptr, typlen, PointerGetDatum(ptr));
|
|
ptr = (char *) att_align(ptr, typalign);
|
|
}
|
|
|
|
/*
|
|
* Prep work is finally done. Go get the SQL string.
|
|
*/
|
|
sql = get_sql_insert(relid, pkattnums, pknumatts, src_pkattvals, tgt_pkattvals);
|
|
|
|
/*
|
|
* Make it into TEXT for return to the client
|
|
*/
|
|
sql_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(sql)));
|
|
|
|
/*
|
|
* And send it
|
|
*/
|
|
PG_RETURN_TEXT_P(sql_text);
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_build_sql_delete
|
|
*
|
|
* Used to generate an SQL delete statement.
|
|
* This is useful for selectively replicating a
|
|
* delete to another server via dblink.
|
|
*
|
|
* API:
|
|
* <relname> - name of remote table of interest
|
|
* <pkattnums> - an int2vector of attnums which will be used
|
|
* to identify the remote tuple of interest
|
|
* <pknumatts> - number of attnums in pkattnums
|
|
* <tgt_pkattvals_arry> - text array of key values which will be used
|
|
* to build the string for execution remotely.
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_build_sql_delete);
|
|
Datum
|
|
dblink_build_sql_delete(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid relid;
|
|
text *relname_text;
|
|
int16 *pkattnums;
|
|
int pknumatts_tmp;
|
|
int16 pknumatts = 0;
|
|
char **tgt_pkattvals;
|
|
ArrayType *tgt_pkattvals_arry;
|
|
int tgt_ndim;
|
|
int *tgt_dim;
|
|
int tgt_nitems;
|
|
int i;
|
|
char *ptr;
|
|
char *sql;
|
|
text *sql_text;
|
|
int16 typlen;
|
|
bool typbyval;
|
|
char typalign;
|
|
|
|
relname_text = PG_GETARG_TEXT_P(0);
|
|
|
|
/*
|
|
* Convert relname to rel OID.
|
|
*/
|
|
relid = get_relid_from_relname(relname_text);
|
|
if (!OidIsValid(relid))
|
|
elog(ERROR, "dblink_build_sql_delete: relation does not exist");
|
|
|
|
pkattnums = (int16 *) PG_GETARG_POINTER(1);
|
|
pknumatts_tmp = PG_GETARG_INT32(2);
|
|
if (pknumatts_tmp <= SHRT_MAX)
|
|
pknumatts = pknumatts_tmp;
|
|
else
|
|
elog(ERROR, "Bad input value for pknumatts; too large");
|
|
|
|
/*
|
|
* There should be at least one key attribute
|
|
*/
|
|
if (pknumatts == 0)
|
|
elog(ERROR, "dblink_build_sql_insert: number of key attributes must be > 0.");
|
|
|
|
tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
|
|
|
|
/*
|
|
* Target array is made up of key values that will be used to build
|
|
* the SQL string for use on the remote system.
|
|
*/
|
|
tgt_ndim = ARR_NDIM(tgt_pkattvals_arry);
|
|
tgt_dim = ARR_DIMS(tgt_pkattvals_arry);
|
|
tgt_nitems = ArrayGetNItems(tgt_ndim, tgt_dim);
|
|
|
|
/*
|
|
* There should be one target array key value for each key attnum
|
|
*/
|
|
if (tgt_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: target key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input target array
|
|
*/
|
|
Assert(ARR_ELEMTYPE(tgt_pkattvals_arry) == TEXTOID);
|
|
get_typlenbyvalalign(ARR_ELEMTYPE(tgt_pkattvals_arry),
|
|
&typlen, &typbyval, &typalign);
|
|
|
|
tgt_pkattvals = (char **) palloc(tgt_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(tgt_pkattvals_arry);
|
|
for (i = 0; i < tgt_nitems; i++)
|
|
{
|
|
tgt_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr = att_addlength(ptr, typlen, PointerGetDatum(ptr));
|
|
ptr = (char *) att_align(ptr, typalign);
|
|
}
|
|
|
|
/*
|
|
* Prep work is finally done. Go get the SQL string.
|
|
*/
|
|
sql = get_sql_delete(relid, pkattnums, pknumatts, tgt_pkattvals);
|
|
|
|
/*
|
|
* Make it into TEXT for return to the client
|
|
*/
|
|
sql_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(sql)));
|
|
|
|
/*
|
|
* And send it
|
|
*/
|
|
PG_RETURN_TEXT_P(sql_text);
|
|
}
|
|
|
|
|
|
/*
|
|
* dblink_build_sql_update
|
|
*
|
|
* Used to generate an SQL update statement
|
|
* based on an existing tuple in a local relation.
|
|
* This is useful for selectively replicating data
|
|
* to another server via dblink.
|
|
*
|
|
* API:
|
|
* <relname> - name of local table of interest
|
|
* <pkattnums> - an int2vector of attnums which will be used
|
|
* to identify the local tuple of interest
|
|
* <pknumatts> - number of attnums in pkattnums
|
|
* <src_pkattvals_arry> - text array of key values which will be used
|
|
* to identify the local tuple of interest
|
|
* <tgt_pkattvals_arry> - text array of key values which will be used
|
|
* to build the string for execution remotely. These are substituted
|
|
* for their counterparts in src_pkattvals_arry
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_build_sql_update);
|
|
Datum
|
|
dblink_build_sql_update(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid relid;
|
|
text *relname_text;
|
|
int16 *pkattnums;
|
|
int pknumatts_tmp;
|
|
int16 pknumatts = 0;
|
|
char **src_pkattvals;
|
|
char **tgt_pkattvals;
|
|
ArrayType *src_pkattvals_arry;
|
|
ArrayType *tgt_pkattvals_arry;
|
|
int src_ndim;
|
|
int *src_dim;
|
|
int src_nitems;
|
|
int tgt_ndim;
|
|
int *tgt_dim;
|
|
int tgt_nitems;
|
|
int i;
|
|
char *ptr;
|
|
char *sql;
|
|
text *sql_text;
|
|
int16 typlen;
|
|
bool typbyval;
|
|
char typalign;
|
|
|
|
relname_text = PG_GETARG_TEXT_P(0);
|
|
|
|
/*
|
|
* Convert relname to rel OID.
|
|
*/
|
|
relid = get_relid_from_relname(relname_text);
|
|
if (!OidIsValid(relid))
|
|
elog(ERROR, "dblink_build_sql_update: relation does not exist");
|
|
|
|
pkattnums = (int16 *) PG_GETARG_POINTER(1);
|
|
pknumatts_tmp = PG_GETARG_INT32(2);
|
|
if (pknumatts_tmp <= SHRT_MAX)
|
|
pknumatts = pknumatts_tmp;
|
|
else
|
|
elog(ERROR, "Bad input value for pknumatts; too large");
|
|
|
|
/*
|
|
* There should be one source array key values for each key attnum
|
|
*/
|
|
if (pknumatts == 0)
|
|
elog(ERROR, "dblink_build_sql_insert: number of key attributes must be > 0.");
|
|
|
|
src_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(3);
|
|
tgt_pkattvals_arry = PG_GETARG_ARRAYTYPE_P(4);
|
|
|
|
/*
|
|
* Source array is made up of key values that will be used to locate
|
|
* the tuple of interest from the local system.
|
|
*/
|
|
src_ndim = ARR_NDIM(src_pkattvals_arry);
|
|
src_dim = ARR_DIMS(src_pkattvals_arry);
|
|
src_nitems = ArrayGetNItems(src_ndim, src_dim);
|
|
|
|
/*
|
|
* There should be one source array key value for each key attnum
|
|
*/
|
|
if (src_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: source key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input source array
|
|
*/
|
|
Assert(ARR_ELEMTYPE(src_pkattvals_arry) == TEXTOID);
|
|
get_typlenbyvalalign(ARR_ELEMTYPE(src_pkattvals_arry),
|
|
&typlen, &typbyval, &typalign);
|
|
|
|
src_pkattvals = (char **) palloc(src_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(src_pkattvals_arry);
|
|
for (i = 0; i < src_nitems; i++)
|
|
{
|
|
src_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr = att_addlength(ptr, typlen, PointerGetDatum(ptr));
|
|
ptr = (char *) att_align(ptr, typalign);
|
|
}
|
|
|
|
/*
|
|
* Target array is made up of key values that will be used to build
|
|
* the SQL string for use on the remote system.
|
|
*/
|
|
tgt_ndim = ARR_NDIM(tgt_pkattvals_arry);
|
|
tgt_dim = ARR_DIMS(tgt_pkattvals_arry);
|
|
tgt_nitems = ArrayGetNItems(tgt_ndim, tgt_dim);
|
|
|
|
/*
|
|
* There should be one target array key value for each key attnum
|
|
*/
|
|
if (tgt_nitems != pknumatts)
|
|
elog(ERROR, "dblink_build_sql_insert: target key array length does not match number of key attributes.");
|
|
|
|
/*
|
|
* get array of pointers to c-strings from the input target array
|
|
*/
|
|
Assert(ARR_ELEMTYPE(tgt_pkattvals_arry) == TEXTOID);
|
|
get_typlenbyvalalign(ARR_ELEMTYPE(tgt_pkattvals_arry),
|
|
&typlen, &typbyval, &typalign);
|
|
|
|
tgt_pkattvals = (char **) palloc(tgt_nitems * sizeof(char *));
|
|
ptr = ARR_DATA_PTR(tgt_pkattvals_arry);
|
|
for (i = 0; i < tgt_nitems; i++)
|
|
{
|
|
tgt_pkattvals[i] = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(ptr)));
|
|
ptr = att_addlength(ptr, typlen, PointerGetDatum(ptr));
|
|
ptr = (char *) att_align(ptr, typalign);
|
|
}
|
|
|
|
/*
|
|
* Prep work is finally done. Go get the SQL string.
|
|
*/
|
|
sql = get_sql_update(relid, pkattnums, pknumatts, src_pkattvals, tgt_pkattvals);
|
|
|
|
/*
|
|
* Make it into TEXT for return to the client
|
|
*/
|
|
sql_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(sql)));
|
|
|
|
/*
|
|
* And send it
|
|
*/
|
|
PG_RETURN_TEXT_P(sql_text);
|
|
}
|
|
|
|
/*
|
|
* dblink_current_query
|
|
* return the current query string
|
|
* to allow its use in (among other things)
|
|
* rewrite rules
|
|
*/
|
|
PG_FUNCTION_INFO_V1(dblink_current_query);
|
|
Datum
|
|
dblink_current_query(PG_FUNCTION_ARGS)
|
|
{
|
|
text *result_text;
|
|
|
|
result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(debug_query_string)));
|
|
PG_RETURN_TEXT_P(result_text);
|
|
}
|
|
|
|
|
|
/*************************************************************
|
|
* internal functions
|
|
*/
|
|
|
|
|
|
/*
|
|
* init_dblink_results
|
|
* - create an empty dblink_results data structure
|
|
*/
|
|
static dblink_results *
|
|
init_dblink_results(MemoryContext fn_mcxt)
|
|
{
|
|
MemoryContext oldcontext;
|
|
dblink_results *retval;
|
|
|
|
oldcontext = MemoryContextSwitchTo(fn_mcxt);
|
|
|
|
retval = (dblink_results *) palloc(sizeof(dblink_results));
|
|
MemSet(retval, 0, sizeof(dblink_results));
|
|
|
|
retval->tup_num = -1;
|
|
retval->res_id_index = -1;
|
|
retval->res = NULL;
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* get_pkey_attnames
|
|
*
|
|
* Get the primary key attnames for the given relation.
|
|
* Return NULL, and set numatts = 0, if no primary key exists.
|
|
*/
|
|
static char **
|
|
get_pkey_attnames(Oid relid, int16 *numatts)
|
|
{
|
|
Relation indexRelation;
|
|
ScanKeyData entry;
|
|
HeapScanDesc scan;
|
|
HeapTuple indexTuple;
|
|
int i;
|
|
char **result = NULL;
|
|
Relation rel;
|
|
TupleDesc tupdesc;
|
|
|
|
/* open relation using relid, get tupdesc */
|
|
rel = relation_open(relid, AccessShareLock);
|
|
tupdesc = rel->rd_att;
|
|
|
|
/* initialize numatts to 0 in case no primary key exists */
|
|
*numatts = 0;
|
|
|
|
/* use relid to get all related indexes */
|
|
indexRelation = heap_openr(IndexRelationName, AccessShareLock);
|
|
ScanKeyEntryInitialize(&entry, 0, Anum_pg_index_indrelid,
|
|
F_OIDEQ, ObjectIdGetDatum(relid));
|
|
scan = heap_beginscan(indexRelation, SnapshotNow, 1, &entry);
|
|
|
|
while ((indexTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
|
|
{
|
|
Form_pg_index index = (Form_pg_index) GETSTRUCT(indexTuple);
|
|
|
|
/* we're only interested if it is the primary key */
|
|
if (index->indisprimary == TRUE)
|
|
{
|
|
i = 0;
|
|
while (index->indkey[i++] != 0)
|
|
(*numatts)++;
|
|
|
|
if (*numatts > 0)
|
|
{
|
|
result = (char **) palloc(*numatts * sizeof(char *));
|
|
|
|
for (i = 0; i < *numatts; i++)
|
|
result[i] = SPI_fname(tupdesc, index->indkey[i]);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
heap_endscan(scan);
|
|
heap_close(indexRelation, AccessShareLock);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return result;
|
|
}
|
|
|
|
static char *
|
|
get_sql_insert(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals)
|
|
{
|
|
Relation rel;
|
|
char *relname;
|
|
HeapTuple tuple;
|
|
TupleDesc tupdesc;
|
|
int natts;
|
|
StringInfo str = makeStringInfo();
|
|
char *sql;
|
|
char *val;
|
|
int16 key;
|
|
int i;
|
|
bool needComma;
|
|
|
|
/*
|
|
* Open relation using relid
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
relname = RelationGetRelationName(rel);
|
|
tupdesc = rel->rd_att;
|
|
natts = tupdesc->natts;
|
|
|
|
tuple = get_tuple_of_interest(relid, pkattnums, pknumatts, src_pkattvals);
|
|
if (!tuple)
|
|
elog(ERROR, "dblink_build_sql_insert: row not found");
|
|
|
|
appendStringInfo(str, "INSERT INTO %s(", quote_ident_cstr(relname));
|
|
|
|
needComma = false;
|
|
for (i = 0; i < natts; i++)
|
|
{
|
|
if (tupdesc->attrs[i]->attisdropped)
|
|
continue;
|
|
|
|
if (needComma)
|
|
appendStringInfo(str, ",");
|
|
|
|
appendStringInfo(str, "%s",
|
|
quote_ident_cstr(NameStr(tupdesc->attrs[i]->attname)));
|
|
needComma = true;
|
|
}
|
|
|
|
appendStringInfo(str, ") VALUES(");
|
|
|
|
/*
|
|
* remember attvals are 1 based
|
|
*/
|
|
needComma = false;
|
|
for (i = 0; i < natts; i++)
|
|
{
|
|
if (tupdesc->attrs[i]->attisdropped)
|
|
continue;
|
|
|
|
if (needComma)
|
|
appendStringInfo(str, ",");
|
|
|
|
if (tgt_pkattvals != NULL)
|
|
key = get_attnum_pk_pos(pkattnums, pknumatts, i + 1);
|
|
else
|
|
key = -1;
|
|
|
|
if (key > -1)
|
|
val = pstrdup(tgt_pkattvals[key]);
|
|
else
|
|
val = SPI_getvalue(tuple, tupdesc, i + 1);
|
|
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, "%s", quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, "NULL");
|
|
needComma = true;
|
|
}
|
|
appendStringInfo(str, ")");
|
|
|
|
sql = pstrdup(str->data);
|
|
pfree(str->data);
|
|
pfree(str);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return (sql);
|
|
}
|
|
|
|
static char *
|
|
get_sql_delete(Oid relid, int16 *pkattnums, int16 pknumatts, char **tgt_pkattvals)
|
|
{
|
|
Relation rel;
|
|
char *relname;
|
|
TupleDesc tupdesc;
|
|
int natts;
|
|
StringInfo str = makeStringInfo();
|
|
char *sql;
|
|
char *val;
|
|
int i;
|
|
|
|
/*
|
|
* Open relation using relid
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
relname = RelationGetRelationName(rel);
|
|
tupdesc = rel->rd_att;
|
|
natts = tupdesc->natts;
|
|
|
|
appendStringInfo(str, "DELETE FROM %s WHERE ", quote_ident_cstr(relname));
|
|
for (i = 0; i < pknumatts; i++)
|
|
{
|
|
int16 pkattnum = pkattnums[i];
|
|
|
|
if (i > 0)
|
|
appendStringInfo(str, " AND ");
|
|
|
|
appendStringInfo(str, "%s",
|
|
quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum - 1]->attname)));
|
|
|
|
if (tgt_pkattvals != NULL)
|
|
val = pstrdup(tgt_pkattvals[i]);
|
|
else
|
|
{
|
|
elog(ERROR, "Target key array must not be NULL");
|
|
val = NULL; /* keep compiler quiet */
|
|
}
|
|
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, " = %s", quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, " IS NULL");
|
|
}
|
|
|
|
sql = pstrdup(str->data);
|
|
pfree(str->data);
|
|
pfree(str);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return (sql);
|
|
}
|
|
|
|
static char *
|
|
get_sql_update(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals, char **tgt_pkattvals)
|
|
{
|
|
Relation rel;
|
|
char *relname;
|
|
HeapTuple tuple;
|
|
TupleDesc tupdesc;
|
|
int natts;
|
|
StringInfo str = makeStringInfo();
|
|
char *sql;
|
|
char *val;
|
|
int16 key;
|
|
int i;
|
|
bool needComma;
|
|
|
|
/*
|
|
* Open relation using relid
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
relname = RelationGetRelationName(rel);
|
|
tupdesc = rel->rd_att;
|
|
natts = tupdesc->natts;
|
|
|
|
tuple = get_tuple_of_interest(relid, pkattnums, pknumatts, src_pkattvals);
|
|
if (!tuple)
|
|
elog(ERROR, "dblink_build_sql_update: row not found");
|
|
|
|
appendStringInfo(str, "UPDATE %s SET ", quote_ident_cstr(relname));
|
|
|
|
needComma = false;
|
|
for (i = 0; i < natts; i++)
|
|
{
|
|
if (tupdesc->attrs[i]->attisdropped)
|
|
continue;
|
|
|
|
if (needComma)
|
|
appendStringInfo(str, ", ");
|
|
|
|
appendStringInfo(str, "%s = ",
|
|
quote_ident_cstr(NameStr(tupdesc->attrs[i]->attname)));
|
|
|
|
if (tgt_pkattvals != NULL)
|
|
key = get_attnum_pk_pos(pkattnums, pknumatts, i + 1);
|
|
else
|
|
key = -1;
|
|
|
|
if (key > -1)
|
|
val = pstrdup(tgt_pkattvals[key]);
|
|
else
|
|
val = SPI_getvalue(tuple, tupdesc, i + 1);
|
|
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, "%s", quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, "NULL");
|
|
needComma = true;
|
|
}
|
|
|
|
appendStringInfo(str, " WHERE ");
|
|
|
|
for (i = 0; i < pknumatts; i++)
|
|
{
|
|
int16 pkattnum = pkattnums[i];
|
|
|
|
if (i > 0)
|
|
appendStringInfo(str, " AND ");
|
|
|
|
appendStringInfo(str, "%s",
|
|
quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum - 1]->attname)));
|
|
|
|
if (tgt_pkattvals != NULL)
|
|
val = pstrdup(tgt_pkattvals[i]);
|
|
else
|
|
val = SPI_getvalue(tuple, tupdesc, pkattnum);
|
|
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, " = %s", quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, " IS NULL");
|
|
}
|
|
|
|
sql = pstrdup(str->data);
|
|
pfree(str->data);
|
|
pfree(str);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return (sql);
|
|
}
|
|
|
|
/*
|
|
* Return a properly quoted literal value.
|
|
* Uses quote_literal in quote.c
|
|
*/
|
|
static char *
|
|
quote_literal_cstr(char *rawstr)
|
|
{
|
|
text *rawstr_text;
|
|
text *result_text;
|
|
char *result;
|
|
|
|
rawstr_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(rawstr)));
|
|
result_text = DatumGetTextP(DirectFunctionCall1(quote_literal, PointerGetDatum(rawstr_text)));
|
|
result = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(result_text)));
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Return a properly quoted identifier.
|
|
* Uses quote_ident in quote.c
|
|
*/
|
|
static char *
|
|
quote_ident_cstr(char *rawstr)
|
|
{
|
|
text *rawstr_text;
|
|
text *result_text;
|
|
char *result;
|
|
|
|
rawstr_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(rawstr)));
|
|
result_text = DatumGetTextP(DirectFunctionCall1(quote_ident, PointerGetDatum(rawstr_text)));
|
|
result = DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(result_text)));
|
|
|
|
return result;
|
|
}
|
|
|
|
static int16
|
|
get_attnum_pk_pos(int16 *pkattnums, int16 pknumatts, int16 key)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Not likely a long list anyway, so just scan for the value
|
|
*/
|
|
for (i = 0; i < pknumatts; i++)
|
|
if (key == pkattnums[i])
|
|
return i;
|
|
|
|
return -1;
|
|
}
|
|
|
|
static HeapTuple
|
|
get_tuple_of_interest(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals)
|
|
{
|
|
Relation rel;
|
|
char *relname;
|
|
TupleDesc tupdesc;
|
|
StringInfo str = makeStringInfo();
|
|
char *sql = NULL;
|
|
int ret;
|
|
HeapTuple tuple;
|
|
int i;
|
|
char *val = NULL;
|
|
|
|
/*
|
|
* Open relation using relid
|
|
*/
|
|
rel = relation_open(relid, AccessShareLock);
|
|
relname = RelationGetRelationName(rel);
|
|
tupdesc = CreateTupleDescCopy(rel->rd_att);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
/*
|
|
* Connect to SPI manager
|
|
*/
|
|
if ((ret = SPI_connect()) < 0)
|
|
elog(ERROR, "get_tuple_of_interest: SPI_connect returned %d", ret);
|
|
|
|
/*
|
|
* Build sql statement to look up tuple of interest Use src_pkattvals
|
|
* as the criteria.
|
|
*/
|
|
appendStringInfo(str, "SELECT * FROM %s WHERE ", quote_ident_cstr(relname));
|
|
|
|
for (i = 0; i < pknumatts; i++)
|
|
{
|
|
int16 pkattnum = pkattnums[i];
|
|
|
|
if (i > 0)
|
|
appendStringInfo(str, " AND ");
|
|
|
|
appendStringInfo(str, "%s",
|
|
quote_ident_cstr(NameStr(tupdesc->attrs[pkattnum - 1]->attname)));
|
|
|
|
val = pstrdup(src_pkattvals[i]);
|
|
if (val != NULL)
|
|
{
|
|
appendStringInfo(str, " = %s", quote_literal_cstr(val));
|
|
pfree(val);
|
|
}
|
|
else
|
|
appendStringInfo(str, " IS NULL");
|
|
}
|
|
|
|
sql = pstrdup(str->data);
|
|
pfree(str->data);
|
|
pfree(str);
|
|
|
|
/*
|
|
* Retrieve the desired tuple
|
|
*/
|
|
ret = SPI_exec(sql, 0);
|
|
pfree(sql);
|
|
|
|
/*
|
|
* Only allow one qualifying tuple
|
|
*/
|
|
if ((ret == SPI_OK_SELECT) && (SPI_processed > 1))
|
|
elog(ERROR, "get_tuple_of_interest: Source criteria may not match more than one record.");
|
|
else if (ret == SPI_OK_SELECT && SPI_processed == 1)
|
|
{
|
|
SPITupleTable *tuptable = SPI_tuptable;
|
|
|
|
tuple = SPI_copytuple(tuptable->vals[0]);
|
|
|
|
return tuple;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* no qualifying tuples
|
|
*/
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* never reached, but keep compiler quiet
|
|
*/
|
|
return NULL;
|
|
}
|
|
|
|
static Oid
|
|
get_relid_from_relname(text *relname_text)
|
|
{
|
|
RangeVar *relvar;
|
|
Relation rel;
|
|
Oid relid;
|
|
|
|
relvar = makeRangeVarFromNameList(textToQualifiedNameList(relname_text, "get_relid_from_relname"));
|
|
rel = heap_openrv(relvar, AccessShareLock);
|
|
relid = RelationGetRelid(rel);
|
|
relation_close(rel, AccessShareLock);
|
|
|
|
return relid;
|
|
}
|
|
|
|
static dblink_results *
|
|
get_res_ptr(int32 res_id_index)
|
|
{
|
|
List *ptr;
|
|
|
|
/*
|
|
* short circuit empty list
|
|
*/
|
|
if (res_id == NIL)
|
|
return NULL;
|
|
|
|
/*
|
|
* OK, should be good to go
|
|
*/
|
|
foreach(ptr, res_id)
|
|
{
|
|
dblink_results *this_res_id = (dblink_results *) lfirst(ptr);
|
|
|
|
if (this_res_id->res_id_index == res_id_index)
|
|
return this_res_id;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Add node to global List res_id
|
|
*/
|
|
static void
|
|
append_res_ptr(dblink_results * results)
|
|
{
|
|
res_id = lappend(res_id, results);
|
|
}
|
|
|
|
/*
|
|
* Remove node from global List
|
|
* using res_id_index
|
|
*/
|
|
static void
|
|
remove_res_ptr(dblink_results * results)
|
|
{
|
|
res_id = lremove(results, res_id);
|
|
|
|
if (res_id == NIL)
|
|
res_id_index = 0;
|
|
}
|
|
|
|
static TupleDesc
|
|
pgresultGetTupleDesc(PGresult *res)
|
|
{
|
|
int natts;
|
|
AttrNumber attnum;
|
|
TupleDesc desc;
|
|
char *attname;
|
|
int32 atttypmod;
|
|
int attdim;
|
|
bool attisset;
|
|
Oid atttypid;
|
|
int i;
|
|
|
|
/*
|
|
* allocate a new tuple descriptor
|
|
*/
|
|
natts = PQnfields(res);
|
|
if (natts < 1)
|
|
elog(ERROR, "cannot create a description for empty results");
|
|
|
|
desc = CreateTemplateTupleDesc(natts, false);
|
|
|
|
attnum = 0;
|
|
|
|
for (i = 0; i < natts; i++)
|
|
{
|
|
/*
|
|
* for each field, get the name and type information from the
|
|
* query result and have TupleDescInitEntry fill in the attribute
|
|
* information we need.
|
|
*/
|
|
attnum++;
|
|
|
|
attname = PQfname(res, i);
|
|
atttypid = PQftype(res, i);
|
|
atttypmod = PQfmod(res, i);
|
|
|
|
if (PQfsize(res, i) != get_typlen(atttypid))
|
|
elog(ERROR, "Size of remote field \"%s\" does not match size "
|
|
"of local type \"%s\"",
|
|
attname,
|
|
format_type_with_typemod(atttypid, atttypmod));
|
|
|
|
attdim = 0;
|
|
attisset = false;
|
|
|
|
TupleDescInitEntry(desc, attnum, attname, atttypid,
|
|
atttypmod, attdim, attisset);
|
|
}
|
|
|
|
return desc;
|
|
}
|