Loop in stored procedure in SQL server - sql

Question

I need help with writing stored procedure that calls another stored procedure and passes values to it. So far this was done in C#, now I want to move it to stored procedure and make an SQL agent job that calls it at specific time. Any ideas? This is the case.
Table A:
PK_TableA_ID
Table B:
PK_TableB_ID
Stored procedure SP1:
#TableA_ID
#TableB_ID
I need this but in T-SQL
foreach(var TableAId in TableA)
{
foreach(var TableBId in TableB)
{
//call stored procedure
SP1(TableAId, TableBId);
}
}

Answer 1

Here's an example of how you can use cursors to do loops:
-- set up some test data
declare #table_a table (PK_TableA_ID int)
declare #table_b table (PK_TableB_ID int)
insert #table_a values (1),(2),(3)
insert #table_b values (4),(5),(6)
-- do the actual processing
SET NOCOUNT ON
DECLARE #TableA_ID int, #TableB_ID int
DECLARE TableA_cursor CURSOR FOR SELECT PK_TableA_ID FROM #table_a
OPEN TableA_cursor
FETCH NEXT FROM TableA_cursor INTO #TableA_ID
WHILE ##FETCH_STATUS = 0
BEGIN
DECLARE TableB_cursor CURSOR FOR SELECT PK_TableB_ID FROM #table_b
OPEN TableB_cursor
FETCH NEXT FROM TableB_cursor INTO #TableB_ID
WHILE ##FETCH_STATUS = 0
BEGIN
PRINT CAST(#TableA_ID AS CHAR(1)) + ':' + CAST(#TableB_ID AS CHAR(1))
-- execute your stored procedure here:
-- EXEC Your_stored_procedure (#TableA_ID, #TableB_ID)
FETCH NEXT FROM TableB_cursor INTO #TableB_ID
END
CLOSE TableB_cursor
DEALLOCATE TableB_cursor
FETCH NEXT FROM TableA_cursor INTO #TableA_ID
END
CLOSE TableA_cursor
DEALLOCATE TableA_cursor
The cursor above (with the test data in the temporary tables) will generate this output:
1:4
1:5
1:6
2:4
2:5
2:6
3:4
3:5
3:6
Using cursors might not be the best way to solve your problem though.

Answer 2

I have a clean and clear option without cursors for this case using the table ids.
DECLARE
#Counter1 INT,#MaxId1 INT,
#Counter2 INT, #MaxId2 INT
SELECT #Counter1 = min(PK_TableA_ID) , #MaxId1 = max(PK_TableA_ID)
FROM TableA
SELECT #Counter2 = min(PK_TableB_ID) , #MaxId2 = max(PK_TableB_ID)
FROM TableB
WHILE(#Counter1 IS NOT NULL AND #Counter1 <= #MaxId1)
BEGIN
WHILE(#Counter2 IS NOT NULL AND #Counter2 <= #MaxId2)
BEGIN
//call stored procedure
SP1(#Counter1, #Counter2);
SET #Counter2 = #Counter2 + 1
END;
SELECT #Counter2 = min(PK_TableB_ID) , #MaxId2 = max(PK_TableB_ID)
FROM TableB
SET #Counter1 = #Counter1 + 1
END;