Q: How to SUM for Item1 and Item1 + 'char' I have a question about a little SQL problem.
For instance, I have a table Table like this:
|  ITEM  |  VALUE  |
|A0001   |   3     |
|A0001   |   2     |
|A0002   |   2     |
|A0003   |   7     |
|A0003   |   3     |
|A0003U  |   2     |
As you can see, an Item can have may Values. So what I have already done, is to SUM() all value attached to each Item, to obtain his SUM of Value. 
What I want to do now, is adding the values that are attached to an Item and and this Item + 'U'
For example, the SUM of Value for the Item A0003U will be 
7 (line 1 of item) + 3 (line 2 of item) + 2 (line 1 of item + 'U') = 12
I know that I can use the function RIGHT(Item, 1) that will return 'U' if it endswith a 'U', but I don't know how to make all the calculation.
EDIT:
A resulset should be:
|  ITEM  |  VALUE  |
|A0001   |   5     |
|A0002   |   2     |
|A0003   |   12     |

A: This will sum up the values by taking the first 5 characters of the ITEM column and grouping by them. This will include items that end in U
Select Left(ITEM,5),
        SUM(VALUE)
From Table
Group by Left(ITEM,5)

EDIT
Assuming that U is always the last character and only appears once then you can use this alternative:
Select  Case 
            When CHARINDEX('U', ITEM) > 0 Then LEFT(ITEM, CHARINDEX('U', ITEM)-1)
            Else ITEM
        End,
        SUM(VALUE)
From Table
Group by    Case 
            When CHARINDEX('U', ITEM) > 0 Then LEFT(ITEM, CHARINDEX('U', ITEM)-1)
            Else ITEM
            End


A: I over-thought the problem before OP added the expected result-set. Nevertheless here is the query if desired output would be something like:
|  ITEM  |  VALUE  |
|A0001   |   5     |
|A0002   |   2     |
|A0003   |   10    |
|A0003U  |   12    |

It might turn out to be useful: 
SELECT 
   a.ITem
   ,CASE 
      WHEN RIGHT(a.ITEM,1)='U' 
        THEN SUM(b.VALUE) 
        ELSE SUM(a.VALUE) 
      END AS VALUE
FROM table1 a
LEFT JOIN table1 b 
  ON a.ITEM = b.ITEM + 'U' 
  OR (RIGHT(a.ITEM,1)='U' AND a.ITEM = b.ITEM)
GROUP BY a.ITem

SQLFiddle DEMO
EDIT:
Query for simplified (actual) version of problem:
Select 
  CASE 
    WHEN RIGHT(ITEM,1) = 'U' THEN SUBSTRING(ITEM,0,LEN(ITEM)) 
    ELSE ITEM 
  END AS ITEM
  ,SUM(VALUE) as VALUE
From Table1
GROUP BY 
   CASE 
    WHEN RIGHT(ITEM,1) = 'U' THEN SUBSTRING(ITEM,0,LEN(ITEM)) 
    ELSE ITEM 
   END

SQLFiddle DEMO
