postgresql/src/backend/parser
Álvaro Herrera 80d7f99049
Add ATAlterConstraint struct for ALTER .. CONSTRAINT
Replace the use of Constraint with a new ATAlterConstraint struct, which
allows us to pass additional information.  No functionality is added by
this commit.  This is necessary for future work that allows altering
constraints in other ways.

I (Álvaro) took the liberty of restructuring the code for ALTER
CONSTRAINT beyond what Amul did.  The original coding before Amul's
patch was unnecessarily baroque, and this change makes things simpler
by removing one level of subroutine.  Also, partly remove the assumption
that only partitioned tables are relevant (by passing sensible 'recurse'
arguments) and no longer ignore whether ONLY was specified.  I say
'partly' because the current coding only walks down via the 'conparentid'
relationship, which is only used for partitioned tables; but future
patches could handle ONLY or not for other types of constraint changes
for legacy inheritance trees too.

Author: Amul Sul <sulamul@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CAAJ_b94bfgPV-8Mw_HwSBeheVwaK9=5s+7+KbBj_NpwXQFgDGg@mail.gmail.com
2025-02-19 13:06:13 +01:00
..
.gitignore Convert cvsignore to gitignore, and add .gitignore for build targets. 2010-09-22 12:57:04 +02:00
analyze.c Add OLD/NEW support to RETURNING in DML queries. 2025-01-16 14:57:35 +00:00
check_keywords.pl Update copyright for 2025 2025-01-01 11:21:55 -05:00
gram.y Add ATAlterConstraint struct for ALTER .. CONSTRAINT 2025-02-19 13:06:13 +01:00
gramparse.h Update copyright for 2025 2025-01-01 11:21:55 -05:00
Makefile Drop warning-free support for Flex 2.5.35 2025-01-15 15:35:08 +01:00
meson.build Drop warning-free support for Flex 2.5.35 2025-01-15 15:35:08 +01:00
parse_agg.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_clause.c Add OLD/NEW support to RETURNING in DML queries. 2025-01-16 14:57:35 +00:00
parse_coerce.c Require callers of coerce_to_domain() to supply base type/typmod. 2025-01-29 15:42:25 -05:00
parse_collate.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_cte.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_enr.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_expr.c Add OLD/NEW support to RETURNING in DML queries. 2025-01-16 14:57:35 +00:00
parse_func.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_jsontable.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_merge.c Add OLD/NEW support to RETURNING in DML queries. 2025-01-16 14:57:35 +00:00
parse_node.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_oper.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_param.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_relation.c Virtual generated columns 2025-02-07 09:46:59 +01:00
parse_target.c Add OLD/NEW support to RETURNING in DML queries. 2025-01-16 14:57:35 +00:00
parse_type.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
parse_utilcmd.c Add support for LIKE in CREATE FOREIGN TABLE 2025-02-19 15:50:37 +09:00
parser.c Update copyright for 2025 2025-01-01 11:21:55 -05:00
README Remove outdated reference to a removed file 2023-06-15 22:35:42 +09:00
scan.l Drop warning-free support for Flex 2.5.35 2025-01-15 15:35:08 +01:00
scansup.c Update copyright for 2025 2025-01-01 11:21:55 -05:00

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_enr.c	handle ephemeral named rels (trigger transition tables, ...)
parse_func.c	handle functions, table.column and column identifiers
parse_merge.c	handle MERGE
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.