Question

I need to increase the size of a character varying(60) field in a postgres database table without data loss.

I have this command

alter table client_details alter column name set character varying(200);

will this command increase the the field size from 60 to 200 without data loss?

Answer 1

Referring to this documentation, there would be no data loss, alter column only casts old data to new data so a cast between character data should be fine. But I don’t think your syntax is correct, see the documentation I mentioned earlier. I think you should be using this syntax :

ALTER [ COLUMN ] column TYPE type [
USING expression ]

And as a note, wouldn’t it be easier to just create a table, populate it and test 🙂