Looping the records in stored procedure - sql

Question

I have this query..
Begin
declare #Col int,
#lev int,
#Plan int
select #Col = 411
select #lev = 16
select #Plan = 780
--Insert into baCodeLibrary(Plan_Num,Level_Num,Column_Num,Block_Num,Code_Id,Sort_Order,isactive,Added_By,DateTime_Added,Updated_By,DateTime_Updated)
Select Distinct
#plan,
#lev,
#col,
ba_Object_Id - 5539,
ba_Object_Id,
ba_OBject_Desc,
ba_Object_Id - 5539,
1,
'xyz',
GETDATE(),
'xyz',
GETDATE()
from baObject
where ba_OBject_Id > 5539
and ba_Object_Id < 5554
end
Here I have only for the #col = 411, but I want to loop for all the column until 489
Could any body help me out how to write the loop in this query to select all the columns from 411 to 489?
Thanks in advance

Answer 1

How about not thinking about this in terms of a loop, and instead think about it in terms of a set?
declare #lev int,
#Plan int;
select #lev = 16,
#Plan = 780;
;WITH n(n) AS
(
SELECT TOP (489-411) Number
FROM master.dbo.spt_values
WHERE type = N'P' ORDER BY Number
)
--Insert dbo.baCodeLibrary(...)
SELECT DISTINCT
#plan,
#lev,
n.n,
ba.ba_Object_Id - 5539,
ba.ba_Object_Id,
ba.ba_Object_Desc,
ba.ba_Object_Id - 5539,
1,
'xyz',
GETDATE(),
'xyz',
GETDATE()
FROM dbo.baObject AS ba CROSS JOIN n
where ba.ba_Object_Id > 5539
and ba.ba_Object_Id < 5554;

Answer 2

There's no actual looping mechanism in your query as it exists now. You'll need to implement something like a while loop in order to get that functionality.
See: http://technet.microsoft.com/en-us/library/ms178642.aspx
It'll look something like
DECLARE #counter int
SET #counter = 1
WHILE #counter < 10
BEGIN
-- loop logic
SET #counter = #counter + 1
END

Answer 3

Looping can be performed three ways in T-SQL; a WHILE loop, a SET based operation, or a CURSOR.
T-SQL / SQL Server are optimised for SET based operations, and they are easily the most efficient way to loop, but it all depends on what you're trying to achieve.
You may be warned away from cursors, with good reason, but they are perfectly acceptable as long as you understand what you're doing. Here's an example of a very simple, fast cursor:
DECLARE #myColumn VARCHAR(100)
DECLARE cTmp CURSOR FAST_FORWARD FOR
SELECT MyColumn
FROM MyTable (nolock)
OPEN cTmp
FETCH NEXT FROM cTmp INTO #myColumn
WHILE ##FETCH_STATUS = 0
BEGIN
-- Do something with #myColumn here
FETCH NEXT FROM cTmp INTO #myColumn
END
CLOSE cTmp
DEALLOCATE cTmp
GO
Please do not use this code without reading up on cursors first - they should only be used when SET based operations are not suitable. It depends entirely on what you're trying to achieve - cursors can be very resource hungry, and can result in locked records / tables if you're not careful with the hints you apply to them.