Обсуждение: Some Questions About SQL Functions

  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.

You can call one SQL function from another SQL function. I am not sure about regarding recursive calls but I guess that should be fine as well as it is no different from simple function calls.

You need not specify the length in VARCHAR in postgres.




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Thanks & Regards,

Siddharth Saha
Software Engineer | Drishti-Soft Solutions Pvt Ltd | Gurgaon, Delhi-NCR, India

Phone: +91-9711229624 | email: siddharthsaha@drishti-soft.com