stored procedure with if else sql server 2008 - sql

Question

I have 3 tables, I have to check if grandparent table id has records in grandchildren table. If yes, return yes, else return no. Here is my stored procedure. I got an incorrect syntax error. I am new to stored procedure. Please help me.
CREATE PROCEDURE P_Check
#PKG_ID INT,
#S_ID INT,
#FLAG VCHAR(10) OUT
DECLARE IDS CURSOR LOCAL FOR SELECT S_ID FROM T1 WHERE P_ID = #PKG_ID
OPEN IDS
FETCH NEXT FROM IDS into #S_ID
WHILE ##FETCH_STATUS = 0
BEGIN
SELECT * FROM T2 WHERE S_ID = #S_ID
IF ##ROWCOUNT<>0
#FLAG = 'YES'
RETURN
ELSE
#FLAG = 'NO'
FETCH NEXT FROM IDS into #S_ID
END
CLOSE IDS
DEALLOCATE IDS

Answer 1

A few things to check:
I don't think there is a vchar data type in SQL Server unless that is your custom type. So change it to varchar
You forgot the AS
You might want to enclose your logic inside if in between begin and end
Your code that can be compiled:
CREATE PROCEDURE P_Check
#PKG_ID INT,
#S_ID INT,
#FLAG VARCHAR(10) OUT
AS
DECLARE IDS CURSOR LOCAL FOR SELECT S_ID FROM T1 WHERE P_ID = #PKG_ID
OPEN IDS
FETCH NEXT FROM IDS into #S_ID
WHILE ##FETCH_STATUS = 0
BEGIN
SELECT * FROM T2 WHERE S_ID = #S_ID
IF ##ROWCOUNT<>0
BEGIN
SET #FLAG = 'YES'
RETURN
END
ELSE
BEGIN
SET #FLAG = 'NO'
FETCH NEXT FROM IDS into #S_ID
END
END
CLOSE IDS
DEALLOCATE IDS
However, I think your cursor will not be closed as you are returning here IF ##ROWCOUNT<>0. I think what you should do is change this:
IF ##ROWCOUNT<>0
BEGIN
SET #FLAG = 'YES'
RETURN
END
to this:
IF ##ROWCOUNT<>0
BEGIN
SET #FLAG = 'YES'
GOTO ON_EXIT
END
then end your procedure like this:
ON_EXIT:
CLOSE IDS
DEALLOCATE IDS
Then to answer your question in the comment, you are "returning" it already in a sense. You can call and test your procedure like this:
declare #result varchar(10)
exec P_Check 1, 1, #result out
print #result

Answer 2

This is just way too complicated and using a cursor here is totally not needed and totally unnecessary.
Simplify your procedure to be:
CREATE PROCEDURE P_Check
#PKG_ID INT,
#S_ID INT,
#FLAG CHAR(1) OUT
AS BEGIN
IF EXISTS (SELECT * FROM T2
INNER JOIN T1 ON T2.S_ID = T1.S_ID WHERE P_ID = #PKG_ID)
SET #FLAG = 'Y'
ELSE
SET #FLAG = 'N'
END
When working seriously with SQL Server, you need to get away from the procedural row-by-agonizing-row thinking using cursors and loops, and you need to start thinking in sets to be efficient and productive.