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boswellg
Starting Member

1 Post

Posted - 2010-06-10 : 16:09:20

I'm stuck on a really basic query and could use some help. I'm going to feel stupid when I see the answer.

UPDATE Products
SET Products.ReorderLevel = ROUND((2*(Suppliers.LeadTime /22))*Products.Trend,2)
FROM Products INNER JOIN Suppliers ON Products.SupplierID = Suppliers.SupplierID

ReorderLevel, LeadTime, and Trend are all INT

This ALWAYS returns 0 for the ReorderLevel but that's not accurate. For example, if the Trend is 20 and the lead time is 6 it updates ReorderLevel to zero but it should be 11.

Michael Valentine Jones
Yak DBA Kernel (pronounced Colonel)

7020 Posts

Posted - 2010-06-10 : 16:25:13

You are doing integer math instead of decimal math (see difference below).

You should read about both in SQL Server Books Online.

select
	Integer_Math_Result = ROUND((2*(6 /22))*20,2),
	Decimal_Math_Result = ROUND((2*(6.0 /22.0))*20.0,2)

Results:

Integer_Math_Result Decimal_Math_Result 
------------------- ------------------- 
                  0          10.9100000 

(1 row(s) affected)

CODO ERGO SUM

madhivanan
Premature Yak Congratulator

22864 Posts

Posted - 2010-06-11 : 02:53:44

Also refer this post
http://beyondrelational.com/blogs/madhivanan/archive/2008/01/16/beware-of-implicit-conversions.aspx

Madhivanan

Failing to plan is Planning to fail

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