Обсуждение: ALTER column TYPE varying question
I need to increase the length of a string field using version 8.1 I was thinking to use ALTER TABLE since now altering a column type should be supported by pg. The column is currently varying(60) and I want to have it varying(120) After executing ALTER TABLE mytable ALTER COLUMN mycolumn TYPE varchar(120) I can see the column definition correctly changes and I can insert rows with longer data in mycolumn. But when I try to update data which were in the table before the ALTER TABLE I get "ERROR: value too long for type character varying(60)" It's like the old rows didn't update correctly keeping the old maximum length. I can see there's an optional USING clause for the ALTER TYPE, but is not really clear to me what should i add in this case, since basically I'd need no convertion... Thanks Paolo
"Paolo Negri" <hungrylist@gmail.com> writes: > I need to increase the length of a string field using version 8.1 8.1.what? > After executing > ALTER TABLE mytable ALTER COLUMN mycolumn TYPE varchar(120) > I can see the column definition correctly changes and I can insert > rows with longer data in mycolumn. > But when I try to update data which were in the table before the ALTER > TABLE I get > "ERROR: value too long for type character varying(60)" Please provide a self-contained test case. It works in simple cases: regression=# create table mytable (mycolumn varchar(60)); CREATE TABLE regression=# insert into mytable values ('foo'); INSERT 0 1 regression=# ALTER TABLE mytable ALTER COLUMN mycolumn TYPE varchar(120); ALTER TABLE regression=# update mytable set mycolumn = repeat('x',100); UPDATE 1 regression=# It sounds like you have a case where the old table definition is still reflected in a cached plan ... regards, tom lane