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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2012-05-15 12:12:40 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2012-05-16 07:28:25 -0400 |
| commit | 488c6dd1708a2c4a9e9f307001f28c05c48651bd (patch) | |
| tree | d16baea4aecc29adca676952b26ab1c88d7b6c3d /src | |
| parent | 6593c5b5dc39b179b1b7a3c947df2596af3e70c9 (diff) | |
| download | postgresql-488c6dd1708a2c4a9e9f307001f28c05c48651bd.tar.gz postgresql-488c6dd1708a2c4a9e9f307001f28c05c48651bd.zip | |
Improve error message for ALTER COLUMN TYPE coercion failure.
Per recent discussion, the error message for this was actually a trifle
inaccurate, since it said "cannot be cast" which might be incorrect.
Adjust that wording, and add a HINT suggesting that a USING clause might
be needed.
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/commands/tablecmds.c | 7 | ||||
| -rw-r--r-- | src/test/regress/expected/alter_table.out | 8 |
2 files changed, 9 insertions, 6 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index e23a3dab3cd..6148bd62da8 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -7315,8 +7315,9 @@ ATPrepAlterColumnType(List **wqueue, if (transform == NULL) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), - errmsg("column \"%s\" cannot be cast to type %s", - colName, format_type_be(targettype)))); + errmsg("column \"%s\" cannot be cast automatically to type %s", + colName, format_type_be(targettype)), + errhint("Specify a USING expression to perform the conversion."))); /* Fix collations after all else */ assign_expr_collations(pstate, transform); @@ -7482,7 +7483,7 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, if (defaultexpr == NULL) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), - errmsg("default for column \"%s\" cannot be cast to type %s", + errmsg("default for column \"%s\" cannot be cast automatically to type %s", colName, format_type_be(targettype)))); } else diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out index 456a729517f..a0ae5eb9a7b 100644 --- a/src/test/regress/expected/alter_table.out +++ b/src/test/regress/expected/alter_table.out @@ -1673,7 +1673,8 @@ select f3,max(f1) from foo group by f3; -- Simple tests for alter table column type alter table foo alter f1 TYPE integer; -- fails -ERROR: column "f1" cannot be cast to type integer +ERROR: column "f1" cannot be cast automatically to type integer +HINT: Specify a USING expression to perform the conversion. alter table foo alter f1 TYPE varchar(10); create table anothertab (atcol1 serial8, atcol2 boolean, constraint anothertab_chk check (atcol1 <= 3)); @@ -1688,7 +1689,8 @@ select * from anothertab; (2 rows) alter table anothertab alter column atcol1 type boolean; -- fails -ERROR: column "atcol1" cannot be cast to type boolean +ERROR: column "atcol1" cannot be cast automatically to type boolean +HINT: Specify a USING expression to perform the conversion. alter table anothertab alter column atcol1 type integer; select * from anothertab; atcol1 | atcol2 @@ -1723,7 +1725,7 @@ select * from anothertab; alter table anothertab alter column atcol1 type boolean using case when atcol1 % 2 = 0 then true else false end; -- fails -ERROR: default for column "atcol1" cannot be cast to type boolean +ERROR: default for column "atcol1" cannot be cast automatically to type boolean alter table anothertab alter column atcol1 drop default; alter table anothertab alter column atcol1 type boolean using case when atcol1 % 2 = 0 then true else false end; -- fails |