How can I alter the type of a money-column to decimal in PostgreSQL?

Question

I have a table in PostgreSQL where one column "vat" has type money but I would like to alter it to decimal instead.

How can I do it?

I tried with:

alter table my_table alter column vat type decimal;

But I get this error:

ERROR:  column "vat" cannot be cast to type numeric

Any suggestions?

Answer 1

Try providing USING clause as described in docs:

A USING clause must be provided if there is no implicit or assignment cast from old to new type.