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| author | Tom Lane <tgl@sss.pgh.pa.us> | 1999-11-15 02:00:15 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 1999-11-15 02:00:15 +0000 |
| commit | f68e11f373de8b7b1d19203b8edac1a13a8d406d (patch) | |
| tree | c4e61de2b9bd9b8dd7c70545dc861de3547294d4 /src/include/nodes/plannodes.h | |
| parent | 1ecb129d206f30f5813b01e1f1efe75c06febe49 (diff) | |
| download | postgresql-f68e11f373de8b7b1d19203b8edac1a13a8d406d.tar.gz postgresql-f68e11f373de8b7b1d19203b8edac1a13a8d406d.zip | |
Implement subselects in target lists. Also, relax requirement that
subselects can only appear on the righthand side of a binary operator.
That's still true for quantified predicates like x = ANY (SELECT ...),
but a subselect that delivers a single result can now appear anywhere
in an expression. This is implemented by changing EXPR_SUBLINK sublinks
to represent just the (SELECT ...) expression, without any 'left hand
side' or combining operator --- so they're now more like EXISTS_SUBLINK.
To handle the case of '(x, y, z) = (SELECT ...)', I added a new sublink
type MULTIEXPR_SUBLINK, which acts just like EXPR_SUBLINK used to.
But the grammar will only generate one for a multiple-left-hand-side
row expression.
Diffstat (limited to 'src/include/nodes/plannodes.h')
| -rw-r--r-- | src/include/nodes/plannodes.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index a03dacfb02b..e4dc5fde210 100644 --- a/src/include/nodes/plannodes.h +++ b/src/include/nodes/plannodes.h @@ -6,7 +6,7 @@ * * Copyright (c) 1994, Regents of the University of California * - * $Id: plannodes.h,v 1.31 1999/10/17 22:15:07 tgl Exp $ + * $Id: plannodes.h,v 1.32 1999/11/15 02:00:13 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -356,8 +356,8 @@ typedef struct SubPlan List *setParam; /* non-correlated EXPR & EXISTS subqueries * have to set some Params for paren Plan */ List *parParam; /* indices of corr. Vars from parent plan */ - SubLink *sublink; /* SubLink node for subselects in WHERE - * and HAVING */ + SubLink *sublink; /* SubLink node from parser; holds info about + * what to do with subselect's results */ bool shutdown; /* shutdown plan if TRUE */ } SubPlan; |