How to convert column type from varchar to date in PostgreSQL?

Question

I have varchar data type column and date data type column.

I have to update varchar column data into date column in PostgreSQL.

Is it possible?

Thanks.

Answer 1

ALTER TABLE <tablename> ALTER COLUMN <columnname> TYPE DATE 
using to_date(<columnname>, 'YYYY-MM-DD');

Answer 2

UPDATE tableName SET dateColumn=to_date(varcharColumn, 'DD MM YYYY')

Assuming you are saving "07 04 2010"

You can find further examples and explanation in the documentation:

http://www.postgresql.org/docs/current/interactive/functions-formatting.html