No matter how I try to concatenate, I can’t seem to get a parameter to be used by INTERVAL in a function:
CREATE OR REPLACE FUNCTION Testing(TrailingWeeks int) RETURNS date AS $$
BEGIN
RETURN current_date - INTERVAL (CAST(TrailingWeeks AS varchar) || ' weeks');
END;
$$ LANGUAGE plpgsql;
--select * from testing(1);
ERROR: syntax error at or near "CAST" at character 34
QUERY: SELECT current_date - INTERVAL (CAST( $1 AS varchar) || ' weeks')
CONTEXT: SQL statement in PL/PgSQL function "testing" near line 2
I have tried concatenating it as a declared variable (with and without apostrophes)
1 weeks
And
‘1 weeks’
With no success. Any tips?
Many thanks,
Robert
