Question

I have a PostgreSQL (9.0) database with a column card_id which is currently of type integer

I need to change this to type text

What is the most best way to achieve this?

The only solution I can find involves creating a temporary column, dropping the original then renaming, I thought they might be a better method??

Answer 1

Have you tried what the fine manual suggests:

ALTER TABLE table ALTER COLUMN anycol TYPE anytype;

Depending on the current and the new type you may need to add USING ... to this statement.
But in your specific case that should not be necessary I believe.