Postgres: Convert varchar to text

问题:

I screwed up and created a column as a varchar(255) where that is no longer sufficient. I've read that varchar has no performance benefits over text on Postgres, and so would like to convert the varchar to a text column in a safe way that preserves the data.

What's the best way for me to do this?

回答1:

ALTER TABLE table1 ALTER COLUMN column1 TYPE text;