PostgreSQL returns java.sql.Types.OTHER when i select a constant with AS keyword

Question

When run the select on Postgres over java

SELECT '' AS COL1, 0 AS COL2 FROM MYTABLE 1=2;

Column type is Types.OTHER both for COL1 and COL2. As it is obvious resultset has not any row.

But if I have rows in result set using the query below:

SELECT '' AS COL1, 0 AS COL2 FROM MYTABLE;

Type of COL1 is still Types.OTHER but COL2 type is Types.INTEGER. In my case I need Types.VARCHAR and Types.INTEGER even result is empty or not.

Are there any configurations on db layer or jdbc url to get Types.VARCHAR and Types.INTEGER both for two queries.

Answer 1

try explicit cast:

SELECT ''::VARCHAR  AS COL1, 0::INTEGER AS COL2 FROM MYTABLE;