Add Postgres Create trigger support

[zidaye]

We have a trigger that updates the field time

CREATE OR REPLACE FUNCTION updated_at() RETURNS trigger AS $$
BEGIN
    IF (
        NEW IS DISTINCT FROM OLD AND
        NEW.updated_at IS NOT DISTINCT FROM OLD.updated_at
    ) THEN
        NEW.updated_at := current_timestamp;
    END IF;
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

[AugustoFKL]

Isn't this the CREATE FUNCTION statement? (1)

[1] : https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#SQL-invoked-function

[zidaye]

Isn't this the CREATE FUNCTION statement? (1)

[1] : https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html#SQL-invoked-function

when parsing the above sql will return an error, I hope sqlparser will consider supporting parsing such sql.