Execute file with SQLExec containing $$ characters

Question

I\'ve created a sql dump file using pg_dump. This export file contains functions which contain $$ characters. No problem to import the file with psql -f < filename>.

Answer 1

$$ is just the bare minimum for dollar-quoting. Make it (much!) less likely to conflict with strings in the enclosed literal by putting a string between the dollars:

CREATE OR REPLACE FUNCTION time_to_sec(timepoint timestamp with time zone)
  RETURNS bigint LANGUAGE plpgsql AS
$BODY$
DECLARE
 seconds bigint;
 secondsFromEpoch bigint;
 secondsFromMidnight bigint;
BEGIN
 secondsFromEpoch = EXTRACT(EPOCH FROM timepoint)::bigint;
 secondsFromMidnight = EXTRACT(EPOCH FROM CURRENT_TIMESTAMP::date)::bigint;
 seconds = secondsFromEpoch - secondsFromMidnight;
 return seconds;
END;
$BODY$;

More advice

• The assignment operator in plpgsql is :=. = is undocumented and may go away in future releases. More under this related question.

• Use CURRENT_DATE instead of CURRENT_TIMESTAMP::date.

• It is allowed, but I would advise not to use mixed case parameter names in plpgsql. They are case insensitive.

• Most importantly, simplify:

  CREATE OR REPLACE FUNCTION time_to_sec2(timepoint timestamp with time zone)
    RETURNS bigint LANGUAGE plpgsql STABLE AS
  $BODY$
  BEGIN
      RETURN EXTRACT(EPOCH FROM timepoint - current_date)::bigint;
  END;
  $BODY$;
  

  Or even:

  CREATE OR REPLACE FUNCTION time_to_sec3(timepoint timestamp with time zone)
    RETURNS bigint LANGUAGE sql AS
  $BODY$
      SELECT EXTRACT(EPOCH FROM timepoint - current_date)::bigint;
  $BODY$;
  

• Can be declared STABLE!

Also note that the current_timestamp family of functions qualify as stable, since their values do not change within a transaction.

• There is also the closely related function age() in PostgreSQL doing almost, but not quite, the same: it returns a "symbolic" result with standard-years and months. Therefore, expression with age() can yield different results for longer periods of time.

These are all equivalent - except for the last two deviating with longer periods of time:

WITH x(t) AS (VALUES ('2012-07-20 03:51:26+02'::timestamptz))
SELECT time_to_sec(t)  AS t1
      ,time_to_sec2(t) AS t2
      ,time_to_sec3(t) AS t3
      ,EXTRACT(EPOCH FROM t - current_date)::bigint AS t4
      ,EXTRACT(EPOCH FROM age(t, current_date))::bigint AS t5 -- deviates
      ,EXTRACT(EPOCH FROM age(t))::bigint * -1  AS t6  -- deviates
FROM   x;

---

As to the original question: this PostgreSQL error message does not necessarily mean the problem is with the dollar sign:

ERROR: syntax error at or near "$"

Most of the time it's a missing ; before that line. Or maybe an un-escaped special characters in XML, like < > & ? The dollar sign $ should be fine. But I am no expert with ant. There should be more context in the PostgreSQL log.