Oracle function re-write in SQL-Server - sql-server

Question

I have an Oracle function that needs to be converted to SQL-Server function
This is the Oracle Function:
FUNCTION check_education(in_crs_code IN VARCHAR2)
RETURN BOOLEAN IS
v_bool BOOLEAN := FALSE;
v_dummy VARCHAR2(1);
CURSOR find_education IS
SELECT 'x'
FROM KU_LIBRARY_EDUCATION_EXTLOAN
WHERE UPPER(course_code) = UPPER(in_crs_code) AND in_use = 'Y';
BEGIN
OPEN find_education;
FETCH find_education INTO v_dummy;
IF find_education%FOUND THEN
v_bool := TRUE;
ELSE
v_bool := FALSE;
END IF;
CLOSE find_education;
RETURN (v_bool);
END check_education;
This is what I have written in SQL-Server to replicate Oracle function:
CREATE FUNCTION [dbo].[check_education](#in_crs_code VARCHAR(4000))
RETURNS BIT AS
BEGIN
DECLARE #v_bool BIT = 0;
DECLARE #v_dummy VARCHAR(1);
DECLARE find_education CURSOR LOCAL FOR
SELECT 'x'
FROM [dbo].[KU_LIBRARY_EDUCATION_EXTLOAN]
WHERE UPPER(course_code) = UPPER(#in_crs_code)
AND in_use = 'Y';
OPEN find_education;
FETCH find_education INTO #v_dummy;
IF ##CURSOR_ROWS >1 BEGIN
SET #v_bool = 1;
END
ELSE BEGIN
SET #v_bool = 0;
END
CLOSE find_education;
DEALLOCATE find_education;
RETURN (#v_bool);
END;
I would expect the SQL server function to return 1 if the cursor returns 'x' but i'm getting 0. Anu help will be appreciated.

Answer 1

I would suggest using an inline table valued function instead of a scalar function. To make sure this is an inline table valued function it MUST be a single select statement. This means there can't be loops and other stuff. Fortunately this query does not actually need any loops. A simple count will return the number of rows. And any value other than 0 when converted to a bit will always be 1.
CREATE FUNCTION [dbo].[check_education]
(
#in_crs_code VARCHAR(4000)
) RETURNS table as return
SELECT CourseExists = convert(bit, count(*))
FROM [dbo].[KU_LIBRARY_EDUCATION_EXTLOAN]
WHERE UPPER(course_code) = UPPER(#in_crs_code)
AND in_use = 'Y';

Answer 2

This is a mere EXISTS thing, so we could try
CREATE FUNCTION [dbo].[check_education](#in_crs_code VARCHAR(4000)) RETURNS BIT AS
BEGIN
RETURN EXISTS ( <query> )
END;
But as far as I know, SQL Server doesn't accept this (though I cannot say why not - maybe it's because of their lack of a real boolean; Oracle doesn't accept it, because EXISTS is no keyword in their PL/SQL programming language).
So we'd use IF/ THEN/ ELSE:
CREATE FUNCTION [dbo].[check_education](#in_crs_code VARCHAR(4000)) RETURNS BIT AS
BEGIN
IF EXISTS
(
SELECT 'x'
FROM ku_library_education_extloan
WHERE UPPER(course_code) = UPPER(in_crs_code) AND in_use = 'Y'
)
RETURN 1
ELSE
RETURN 0
END
END;
There may be errors, because I've never coded a stored procedure in T-SQL, but anyway, you get the idea.