Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

MsSQL - While, Loop

Posted on 2014-02-18
4
Medium Priority
?
648 Views
Last Modified: 2014-02-20
Hi all Experts

I am writing a statement as belows to update the cost from downside to topside by level.

Actually, I dont want to do "Update" statement for 8 times (from Level 8 to Level 1).

Is there any way to modify the statement instead of 8 times of update action?

Declare @intFlag INT
set @intFlag = 8
while @intFlag <= 8
Begin


Update q
set q.PMaterialCost = a.MC * q.NewUsage
from dbo.tbl_MBMBOM  q
inner join
(select Product,Facility,Parent, sum(MaterialCost) as MC
from dbo.tbl_MBMBOM where period = 201401 and facility = 'AA' and [Level] = @intFlag + 1
group by Parent,Facility,Product
) as  a
on q.child = a.Parent and q.Flag = a.Facility and q.Product = a.Product
where q.Period = 201401 and q.Facility = 'AA' and [Level] = @intFlag

SET @intFlag = @intFlag - 1
CONTINUE;
IF @intFlag = 1
BREAK;
END
0
Comment
Question by:beckyng
  • 2
4 Comments
 
LVL 12

Expert Comment

by:Harish Varghese
ID: 39866806
Hello,

I am not sure about a way to avoid loop here, but wanted to point out some potential issues in your query:
1. If your highest available level is 8, then you may initialize @intFlag = 7, since you are using @intFlag + 1 in your subquery.
2. WHERE condition shows q.Flag = a.Facility; do you mean q.Facility = a.Facility instead?
3. CONTINUE statement skips all subsequent statements till the end of the loop, so it should not be there. In fact, you can remove the CONTINUE and IF @intFlag = 1 BREAK statements, and replace "while @intFlag <= 8" with "while @intFlag >= 1"

By the way, I think this is a complex question and 300 points is too less for this.

-Harish
0
 

Author Comment

by:beckyng
ID: 39866809
Hi Harish

Thanks for reply.

Please kindly assume my update statement is fully correct. Actually, I hope I can eliminate the execute the statement for 8 times on intFlag.

How can I do?

Thanks

Becky
0
 
LVL 35

Expert Comment

by:David Todd
ID: 39868850
Hi Becky,

You have a hierarchy.

There are examples of using cte's to do the selects from these, but I haven't seen an update.
http://technet.microsoft.com/en-us/library/ms186243(v=sql.105).aspx

Can you post structure of dbo.tbl_MBMBOM  and some sample data?

Regards
  David
0
 
LVL 12

Accepted Solution

by:
Harish Varghese earned 1200 total points
ID: 39869629
Hello,

Examples of UPDATE using recursive CTE are available here:
http://msdn.microsoft.com/en-us/library/ms175972.aspx
But using an aggregate may be bit complex.

-Harish
0

Featured Post

How to Use the Help Bell

Need to boost the visibility of your question for solutions? Use the Experts Exchange Help Bell to confirm priority levels and contact subject-matter experts for question attention.  Check out this how-to article for more information.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Windocks is an independent port of Docker's open source to Windows.   This article introduces the use of SQL Server in containers, with integrated support of SQL Server database cloning.
One of the most important things in an application is the query performance. This article intends to give you good tips to improve the performance of your queries.
Via a live example, show how to set up a backup for SQL Server using a Maintenance Plan and how to schedule the job into SQL Server Agent.
Viewers will learn how to use the UPDATE and DELETE statements to change or remove existing data from their tables. Make a table: Update a specific column given a specific row using the UPDATE statement: Remove a set of values using the DELETE s…

877 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question