Type double does not exist in PostgreSQL

Question

I have table like this:

CREATE TABLE workingtime_times
(
  workingno serial NOT NULL,
  checktime character(6) NOT NULL,
  timeoffset double precision DEFAULT 9
)

I create function like this:

CREATE OR REPLACE FUNCTION MyFName()
    RETURNS TABLE(
        CheckTime character varying,
        TimeOffset double 
    ) AS
$BODY$
BEGIN 
    RETURN QUERY 
    SELECT  t.CheckTime, t.TimeOffset
    FROM WorkingTime_Times t
    ORDER BY t.WorkingNo DESC
    limit 1;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100
  ROWS 1000;
ALTER FUNCTION MyFName()
  OWNER TO postgres;

It make an error like this:

type double does not exist

Why we can create an table with column datatype double but return in the function fail. What type we can return in this case?

Answer 1

The name of the type is DOUBLE PRECISIONand not just DOUBLE. Thus, your function header should look like this:

CREATE OR REPLACE FUNCTION MyFName() RETURNS TABLE(
    CheckTime CHARACTER VARYING, TimeOffset DOUBLE PRECISION 
) AS

You may also use type references:

CREATE OR REPLACE FUNCTION MyFName() RETURNS TABLE(
    CheckTime working_intems.checktime%TYPE, 
    TimeOffset workingtime_times.timeoffset%TYPE 
) AS