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> User interface proposal for multi-row function targetlist entries > ================================================================= > 1. Only one targetlist entry may return a set. > 2. Each targetlist item (other than the set returning one) is > repeated for each item in the returned set. > Having gotten no objections (actually, no response at all), I can only assume no one had heartburn with this change. The attached patch covers the first of the two proposals, i.e. restricting the target list to only one set returning function. It compiles cleanly, and passes all regression tests. If there are no objections, please apply. Any suggestions on where this should be documented (other than maybe sql-select)? Thanks, Joe p.s. Here's what the previous example now looks like: CREATE TABLE bar(f1 int, f2 text, f3 int); INSERT INTO bar VALUES(1, 'Hello', 42); INSERT INTO bar VALUES(2, 'Happy', 45); CREATE TABLE foo(a int, b text); INSERT INTO foo VALUES(42, 'World'); INSERT INTO foo VALUES(42, 'Everyone'); INSERT INTO foo VALUES(45, 'Birthday'); INSERT INTO foo VALUES(45, 'New Year'); CREATE TABLE foo2(a int, b text); INSERT INTO foo2 VALUES(42, '!!!!'); INSERT INTO foo2 VALUES(42, '????'); INSERT INTO foo2 VALUES(42, '####'); INSERT INTO foo2 VALUES(45, '$$$$'); CREATE OR REPLACE FUNCTION getfoo(int) RETURNS SETOF text AS ' SELECT b FROM foo WHERE a = $1 ' language 'sql'; CREATE OR REPLACE FUNCTION getfoo2(int) RETURNS SETOF text AS ' SELECT b FROM foo2 WHERE a = $1 ' language 'sql'; regression=# SELECT f1, f2, getfoo(f3) AS f4 FROM bar; f1 | f2 | f4 ----+-------+---------- 1 | Hello | World 1 | Hello | Everyone 2 | Happy | Birthday 2 | Happy | New Year (4 rows) regression=# SELECT f1, f2, getfoo(f3) AS f4, getfoo2(f3) AS f5 FROM bar; ERROR: Only one target list entry may return a set result Joe Conway |
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.. | ||
.cvsignore | ||
analyze.c | ||
gram.y | ||
keywords.c | ||
Makefile | ||
parse_agg.c | ||
parse_clause.c | ||
parse_coerce.c | ||
parse_expr.c | ||
parse_func.c | ||
parse_node.c | ||
parse_oper.c | ||
parse_relation.c | ||
parse_target.c | ||
parse_type.c | ||
parser.c | ||
README | ||
scan.l | ||
scansup.c |
This directory does more than tokenize and parse SQL queries. It also creates Query structures for the various complex queries that is passed to the optimizer and then executor. parser.c things start here scan.l break query into tokens scansup.c handle escapes in input keywords.c turn keywords into specific tokens gram.y parse the tokens and fill query-type-specific structures analyze.c handle post-parse processing for each query type parse_clause.c handle clauses like WHERE, ORDER BY, GROUP BY, ... parse_coerce.c used for coercing expressions of different types parse_expr.c handle expressions like col, col + 3, x = 3 or x = 4 parse_oper.c handle operations in expressions parse_agg.c handle aggregates, like SUM(col1), AVG(col2), ... parse_func.c handle functions, table.column and column identifiers parse_node.c create nodes for various structures parse_target.c handle the result list of the query parse_relation.c support routines for tables and column handling parse_type.c support routines for type handling