Subtract the amount over?

Transact-SQL
1

Hello I'm trying to come up with a query that will subtract the overage from a column. I have a table that has a column sku and sometime the update has a greater amount than 15, and that the limit that we can use. So far I'm using this:

UPDATE updatepos
SET sku = left(sku, LEN(sku) - 2)
WHERE (LEN(sku) > 15)

but the over amount varies so that doesn't work all the time. How could I get it to subtract the amount that it's over 15?

Thanks for any help.

2

Please proved some sample data and expected output (from your provided sample data).

3 
UPDATE updatepos
SET sky = LEFT(sku, 15) 
WHERE LEN(sku) > 15;

Why not do it this way if you are always removing anything over 15.

4

That work great, thanks!