[PATCHES] ADD COLUMN with PRIMARY KEY bug (was: I think this is a BUG?)

2008-04-24 Thread Brendan Jurd
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Hi,

The attached patch resolves the bug reported by Kaloyan Iliev [1] on -general.

The problem occurred when executing ALTER TABLE ... ADD COLUMN ...
PRIMARY KEY with no default clause, on a table with rows already
present.  The NOT NULL constraint was not enforced.  The bug has been
observed on (at least) 8.2, 8.3 and CVS HEAD.

The fix was to force evaluation of the NOT NULL constraint in
ATExecAddColumn in all cases where the parser indicated that the
column ought to be NOT NULL.

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On Fri, Apr 25, 2008 at 3:46 AM, Tom Lane [EMAIL PROTECTED] wrote:
  alter table t1 add column f2 int not null;

  transformAlterTableStmt will produce an AT_AddColumn subcommand
  containing a ColumnDef with is_not_null = false, followed by an
  AT_SetNotNull subcommand.  But for


I realised that there's no reason for preparing a separate SetNotNull
subcommand anymore, now that ATExecAddColumn takes care of enforcing
the constraint, so I removed this special case.

I've also added a regression test for ADD COLUMN PRIMARY KEY.

Cheers,
BJ

[1] http://archives.postgresql.org/message-id/[EMAIL PROTECTED]
*** src/backend/commands/tablecmds.c
--- src/backend/commands/tablecmds.c
***
*** ,3338  ATExecAddColumn(AlteredTableInfo *tab, Relation rel,
--- ,3345 
}
  
/*
+* Tell Phase 3 to perform the check for NULL values in the new column 
if
+* its attnotnull bit has been set to true.
+*/
+   if (attribute-attnotnull)
+   tab-new_notnull = true;
+ 
+   /*
 * Add needed dependency entries for the new column.
 */
add_column_datatype_dependency(myrelid, i, attribute-atttypid);
*** src/backend/parser/parse_utilcmd.c
--- src/backend/parser/parse_utilcmd.c
***
*** 1726,1753  transformAlterTableStmt(AlterTableStmt *stmt, const char 
*queryString)
 * If the column has a non-null 
default, we can't skip
 * validation of foreign keys.
 */
!   if (((ColumnDef *) 
cmd-def)-raw_default != NULL)
skipValidation = false;
  
newcmds = lappend(newcmds, cmd);
  
/*
-* Convert an ADD COLUMN ... NOT NULL 
constraint to a
-* separate command
-*/
-   if (def-is_not_null)
-   {
-   /* Remove NOT NULL from 
AddColumn */
-   def-is_not_null = false;
- 
-   /* Add as a separate 
AlterTableCmd */
-   newcmd = 
makeNode(AlterTableCmd);
-   newcmd-subtype = AT_SetNotNull;
-   newcmd-name = 
pstrdup(def-colname);
-   newcmds = lappend(newcmds, 
newcmd);
-   }
- 
-   /*
 * All constraints are processed in 
other ways. Remove the
 * original list
 */
--- 1726,1737 
 * If the column has a non-null 
default, we can't skip
 * validation of foreign keys.
 */
!   if (def-raw_default != NULL)
skipValidation = false;
  
newcmds = lappend(newcmds, cmd);
  
/*
 * All constraints are processed in 
other ways. Remove the
 * original list
 */
*** src/test/regress/expected/alter_table.out
--- src/test/regress/expected/alter_table.out
***
*** 505,510  create table atacc1 ( test int );
--- 505,522 
  alter table atacc1 add constraint atacc_test1 primary key (test1);
  ERROR:  column test1 named in key does not exist
  drop table atacc1;
+ -- Adding a new column as primary key to a non-empty table.  Should fail 
unless
+ -- the column has a default value.
+ create table atacc1 ( test int );
+ insert into atacc1 

Re: [PATCHES] ADD COLUMN with PRIMARY KEY bug (was: I think this is a BUG?)

2008-04-24 Thread Tom Lane
Brendan Jurd [EMAIL PROTECTED] writes:
 I realised that there's no reason for preparing a separate SetNotNull
 subcommand anymore, now that ATExecAddColumn takes care of enforcing
 the constraint, so I removed this special case.

This part seems to me to be code beautification, not a bug-fix, and
shouldn't be back-patched (particularly in view of the fact that we
haven't tested the change all that much --- there might be other
places depending on the old behavior).

Will take care of this.

regards, tom lane

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Re: [PATCHES] ADD COLUMN with PRIMARY KEY bug (was: I think this is a BUG?)

2008-04-24 Thread Tom Lane
Brendan Jurd [EMAIL PROTECTED] writes:
 The attached patch resolves the bug reported by Kaloyan Iliev [1] on -general.

Applied as two separate patches (bug fix and inessential cleanup).
The bug turns out to date back to the original addition of support for
ALTER ... ADD COLUMN ... DEFAULT/NOT NULL in 8.0.

regards, tom lane

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