Hi guys.
I have these questions about SQL functions. some of them are not covered
in documentation:
1. Can a SQL function call another SQL function?
2. How about recursive calls?
3. Consider we have function that has a varchar argument.
CREATE FUNCTION func(varchar) RETURN void AS $$
some SQL queries.
$$ LANGUAGE SQL;
Should we define the argument, varchar or we should define the length
too like varchar(20)? How about return values?
4. consider this example:
we have table named student and a function like this: it only gets a
student row and add that row to the student table.
CREATE FUNCTION add_new(student) RETURNS void AS $$
INSERT INTO student VALUES ($1);
$$ LANGUAGE SQL;
is this function syntactically right?
Thank you very much.