SQL Server在子字符串中使用条件

Question

I have a field of data which consists of account numbers like this

16530907-00
16530907-0001

16589553-00
16589553-00

I want to select everything to the right of the hyphen then if the Length of that substring is >2 I want to Update that field and set it to itself minus the two extra digits on the right.

I am practicing with a select statement

Select SUBSTRING(Account, CHARINDEX('-'), Account)+1, LEN(Account) as test
FROM Documents
WHERE SubmissionID=45925 and LEN(test)>2

This does not work. What I really want to do is create an update statement that tests the characters to the right of the hyphen if there are more than 2 characters then truncate any extra characters .

Any suggestions would be appreciated. Thanks

Answer 1

Try this:

Select SUBSTRING(Account,0,CHARINDEX('-',Account)+3) as UpdatedAccount, Account
FROM Documents 
WHERE SubmissionID=45925 
and LEN(SUBSTRING(Account, CHARINDEX('-',Account)+1,LEN(Account)) ) > 2
AND CHARINDEX('-',Account) > 0

It's ugly but appears do do what you want

Your update would look like this:

UPDATE Documents
SET Account = SUBSTRING(Account,0,CHARINDEX('-',Account)+3)
WHERE SubmissionID=45925 
and LEN(SUBSTRING(Account, CHARINDEX('-',Account)+1,LEN(Account)) ) > 2
AND CHARINDEX('-',Account) > 0

UPDATE:

Added in a check for no hyphen scenarios so you don't undate for no reason. That said, I would recommend going with @Richards solution. It's much prettier.

Answer 2

You could use a Common Table Expression if you are using SQL Server 2005 or greater.

WITH CTE
AS
    (
    SELECT Account 
        , CHARINDEX('-', Account) AS [Dash Index]
        , CASE 
            WHEN CHARINDEX('-', Account)+2 > 2
                THEN CHARINDEX('-', Account)+2
            ELSE LEN(Account)
          END AS [Acceptable Length]
        , LEN(Account) AS [Total Length]
    FROM Documents
    )
UPDATE CTE
SET Account = SUBSTRING(Account, 1, [Acceptable Length])
WHERE [Total Length] <> [Acceptable Length]

Answer 3

UPDATE Documents
SET Account = STUFF(Account, CharIndex('-', Account)+3, 1000, '')
where SubmissionID=45925 AND Account like '%-___%'

Answer 4

Thanks to everyone for their comments and suggestions. I used some of what was here to devise a solution that I think will work well for me. Here it is.

Update Documents
Set Acount=LEFT(Account,Len(Account)-2)
WHERE Submid=41632 AND Account LIKE '%-____'

(Thanks to @Richard for that last bit!')