diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2002-08-02 18:15:10 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2002-08-02 18:15:10 +0000 |
| commit | 38bb77a5d15aa022248488bc8c0147139ce120a9 (patch) | |
| tree | d01573bceae2db61eb97421f91c6068ef8522b66 /src/backend/optimizer/prep/preptlist.c | |
| parent | 5e6528adf726429463a5c1f3edf712f98d6b5f7e (diff) | |
| download | postgresql-38bb77a5d15aa022248488bc8c0147139ce120a9.tar.gz postgresql-38bb77a5d15aa022248488bc8c0147139ce120a9.zip | |
ALTER TABLE DROP COLUMN works. Patch by Christopher Kings-Lynne,
code review by Tom Lane. Remaining issues: functions that take or
return tuple types are likely to break if one drops (or adds!)
a column in the table defining the type. Need to think about what
to do here.
Along the way: some code review for recent COPY changes; mark system
columns attnotnull = true where appropriate, per discussion a month ago.
Diffstat (limited to 'src/backend/optimizer/prep/preptlist.c')
| -rw-r--r-- | src/backend/optimizer/prep/preptlist.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c index 1cc9f5af489..b7c0bac12c8 100644 --- a/src/backend/optimizer/prep/preptlist.c +++ b/src/backend/optimizer/prep/preptlist.c @@ -15,7 +15,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.53 2002/06/20 20:29:31 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.54 2002/08/02 18:15:06 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -165,6 +165,8 @@ expand_targetlist(List *tlist, int command_type, * * For UPDATE, generate a Var reference to the existing value of * the attribute, so that it gets copied to the new tuple. + * But generate a NULL for dropped columns (we want to drop any + * old values). */ Oid atttype = att_tup->atttypid; int32 atttypmod = att_tup->atttypmod; @@ -182,11 +184,21 @@ expand_targetlist(List *tlist, int command_type, false); break; case CMD_UPDATE: - new_expr = (Node *) makeVar(result_relation, - attrno, - atttype, - atttypmod, - 0); + /* Insert NULLs for dropped columns */ + if (att_tup->attisdropped) + new_expr = (Node *) makeConst(atttype, + att_tup->attlen, + (Datum) 0, + true, /* isnull */ + att_tup->attbyval, + false, /* not a set */ + false); + else + new_expr = (Node *) makeVar(result_relation, + attrno, + atttype, + atttypmod, + 0); break; default: elog(ERROR, "expand_targetlist: unexpected command_type"); @@ -210,7 +222,8 @@ expand_targetlist(List *tlist, int command_type, * the end of the new tlist, making sure they have resnos higher than * the last real attribute. (Note: although the rewriter already did * such renumbering, we have to do it again here in case we are doing - * an UPDATE in an inheritance child table with more columns.) + * an UPDATE in a table with dropped columns, or an inheritance child + * table with extra columns.) */ while (tlist) { |