Store select query's output in one array in postgres

Question

My code is:

SELECT column_name FROM information.SCHEMA.columns WHERE table_name = 'aean' 

It returns column names of table aean.
Now I have declared an array:

DECLARE colnames text[] 

How can I store select's output in colnames array.
Is there any need to initialize colnames?

Answer 1

There are two ways. One is to aggregate:

SELECT array_agg(column_name::TEXT) FROM information.schema.columns WHERE table_name = 'aean' 

The other is to use an array constructor:

SELECT ARRAY(     SELECT column_name      FROM information_schema.columns      WHERE table_name = 'aean' ) 

I'm presuming this is for plpgsql. In that case you can assign it like this:

colnames := ARRAY(     SELECT column_name     FROM information_schema.columns     WHERE table_name='aean' );