postgresql/src/backend/parser
Tom Lane 7421f4b89a Fix incorrect handling of CTEs and ENRs as DML target relations.
setTargetTable threw an error if the proposed target RangeVar's relname
matched any visible CTE or ENR.  This breaks backwards compatibility in
the CTE case, since pre-v10 we never looked for a CTE here at all, so that
CTE names did not mask regular tables.  It does seem like a good idea to
throw an error for the ENR case, though, thus causing ENRs to mask tables
for this purpose; ENRs are new in v10 so we're not breaking existing code,
and we may someday want to allow them to be the targets of DML.

To fix that, replace use of getRTEForSpecialRelationTypes, which was
overkill anyway, with use of scanNameSpaceForENR.

A second problem was that the check neglected to verify null schemaname,
so that a CTE or ENR could incorrectly be thought to match a qualified
RangeVar.  That happened because getRTEForSpecialRelationTypes relied
on its caller to have checked for null schemaname.  Even though the one
remaining caller got it right, this is obviously bug-prone, so move
the check inside getRTEForSpecialRelationTypes.

Also, revert commit 18ce3a4ab's extremely poorly thought out decision to
add a NULL return case to parserOpenTable --- without either documenting
that or adjusting any of the callers to check for it.  The current bug
seems to have arisen in part due to working around that bad idea.

In passing, remove the one-line shim functions transformCTEReference and
transformENRReference --- they don't seem to be adding any clarity or
functionality.

Per report from Hugo Mercier (via Julien Rouhaud).  Back-patch to v10
where the bug was introduced.

Thomas Munro, with minor editing by me

Discussion: https://postgr.es/m/CAOBaU_YdPVH+PTtiKSSLOiiW3mVDYsnNUekK+XPbHXiP=wrFLA@mail.gmail.com
2017-10-16 17:56:54 -04:00
..
.gitignore Convert cvsignore to gitignore, and add .gitignore for build targets. 2010-09-22 12:57:04 +02:00
Makefile Add infrastructure to support EphemeralNamedRelation references. 2017-03-31 23:17:18 -05:00
README Move keywords.c/kwlookup.c into src/common/. 2016-03-23 20:22:08 -04:00
analyze.c Change tupledesc->attrs[n] to TupleDescAttr(tupledesc, n). 2017-08-20 11:19:07 -07:00
check_keywords.pl Post-PG 10 beta1 pgperltidy run 2017-05-17 19:01:23 -04:00
gram.y Allow multiple tables to be specified in one VACUUM or ANALYZE command. 2017-10-03 18:53:44 -04:00
parse_agg.c Re-allow SRFs and window functions within sub-selects within aggregates. 2017-06-27 17:51:11 -04:00
parse_clause.c Fix incorrect handling of CTEs and ENRs as DML target relations. 2017-10-16 17:56:54 -04:00
parse_coerce.c Support arrays over domains. 2017-09-30 13:40:56 -04:00
parse_collate.c Phase 3 of pgindent updates. 2017-06-21 15:35:54 -04:00
parse_cte.c Phase 3 of pgindent updates. 2017-06-21 15:35:54 -04:00
parse_enr.c Add infrastructure to support EphemeralNamedRelation references. 2017-03-31 23:17:18 -05:00
parse_expr.c Reduce excessive dereferencing of function pointers 2017-09-07 13:56:09 -04:00
parse_func.c Change tupledesc->attrs[n] to TupleDescAttr(tupledesc, n). 2017-08-20 11:19:07 -07:00
parse_node.c Phase 3 of pgindent updates. 2017-06-21 15:35:54 -04:00
parse_oper.c Improve plural handling in error message 2017-08-23 13:56:59 -04:00
parse_param.c Phase 3 of pgindent updates. 2017-06-21 15:35:54 -04:00
parse_relation.c Fix incorrect handling of CTEs and ENRs as DML target relations. 2017-10-16 17:56:54 -04:00
parse_target.c Reduce excessive dereferencing of function pointers 2017-09-07 13:56:09 -04:00
parse_type.c Phase 3 of pgindent updates. 2017-06-21 15:35:54 -04:00
parse_utilcmd.c After a MINVALUE/MAXVALUE bound, allow only more of the same. 2017-09-15 21:15:55 -04:00
parser.c Change representation of statement lists, and add statement location info. 2017-01-14 16:02:35 -05:00
scan.l Exclude flex-generated code from coverage testing 2017-10-16 16:28:11 -04:00
scansup.c Update copyright via script for 2017 2017-01-03 13:48:53 -05:00

README

src/backend/parser/README

Parser
======

This directory does more than tokenize and parse SQL queries.  It also
creates Query structures for the various complex queries that are passed
to the optimizer and then executor.

parser.c	things start here
scan.l		break query into tokens
scansup.c	handle escapes in input strings
gram.y		parse the tokens and produce a "raw" parse tree
analyze.c	top level of parse analysis for optimizable queries
parse_agg.c	handle aggregates, like SUM(col1),  AVG(col2), ...
parse_clause.c	handle clauses like WHERE, ORDER BY, GROUP BY, ...
parse_coerce.c	handle coercing expressions to different data types
parse_collate.c	assign collation information in completed expressions
parse_cte.c	handle Common Table Expressions (WITH clauses)
parse_expr.c	handle expressions like col, col + 3, x = 3 or x = 4
parse_func.c	handle functions, table.column and column identifiers
parse_node.c	create nodes for various structures
parse_oper.c	handle operators in expressions
parse_param.c	handle Params (for the cases used in the core backend)
parse_relation.c support routines for tables and column handling
parse_target.c	handle the result list of the query
parse_type.c	support routines for data type handling
parse_utilcmd.c	parse analysis for utility commands (done at execution time)

See also src/common/keywords.c, which contains the table of standard
keywords and the keyword lookup function.  We separated that out because
various frontend code wants to use it too.