Postgres为时间戳转换创建函数

Question

I'm trying to create a postgres function which converts the input timestamp to PDT. Here is my code:

CREATE OR REPLACE FUNCTION getPdtTimestamp(inTS TIMESTAMP) RETURNS TIMESTAMP AS $$
DECLARE
    outTS TIMESTAMP;
BEGIN
    SELECT TIMESTAMP with time zone inTS AT TIME ZONE 'PDT' INTO outTS;
    RETURN outTS;
END;
$$ LANGUAGE plpgsql;

The error I get here is:

syntax error at or near "inTS"

My goal is to make a function of a query which looks like this:

SELECT TIMESTAMP with time zone '2012-01-01 12:00:00' AT TIME ZONE 'PDT';
// returns a value

Thanks in advance

Answer 1

This should work:

CREATE FUNCTION getPdtTimestamp(timestamp) RETURNS TIMESTAMP AS $$ 
    SELECT $1::TIMESTAMP with time zone  AT TIME ZONE 'PDT';
$$ LANGUAGE SQL;