SQL選擇與Len - 轉換失敗？

Question

這是我的查詢：

SELECT at.AssetTag, 
dp.Custodian, 
CASE WHEN PATINDEX('%_%', dp.Custodian) = '0' 
THEN dp.Custodian 
ELSE RIGHT(LTRIM(RTRIM(dp.Custodian)),LEN(LTRIM(RTRIM(dp.Custodian)) - PATINDEX('%_%', dp.Custodian))) END AS FirstName, 
CASE WHEN PATINDEX('%_%', dp.Custodian) = '0' 
THEN '' 
ELSE LEFT(dp.Custodian, PATINDEX('%_%', dp.Custodian)-1) END AS LastName, RIGHT(at.Assettag,3) AS MediaTypeSuffix 
FROM tblAssetTracking at (NOLOCK) 
INNER JOIN tblDiscoveryProcessing dp (NOLOCK) ON dp.FKAsset = at.ID 
WHERE dp.Custodian Is Not Null 

當我運行它，我得到一個錯誤的「nvarchar的值‘XXX’轉換爲數據類型爲int時轉換失敗」（xxx是實際值我不得不更換）。任何人都可以幫忙嗎？ PS。我希望這個聲明能夠進入代碼塊。顯然，我不明白如何正確粘貼代碼。

謝謝！

Answer 1

沒關係。我不得不刪除修整：

SELECT at.AssetTag, 
dp.Custodian, 
CASE WHEN PATINDEX('%[_]%', dp.Custodian) = '0' 
    THEN dp.Custodian 
    ELSE RIGHT(dp.Custodian,LEN(dp.Custodian) - PATINDEX('%[_]%', dp.Custodian)) 
END AS FirstName, 
CASE WHEN PATINDEX('%[_]%', dp.Custodian) = '0' 
    THEN '' 
    ELSE LEFT(dp.Custodian, PATINDEX('%[_]%', dp.Custodian)-1) 
END AS LastName, 
RIGHT(at.Assettag,3) AS MediaTypeSuffix 
FROM tblAssetTracking at (NOLOCK) 
INNER JOIN tblDiscoveryProcessing dp (NOLOCK) ON dp.FKAsset = at.ID 
WHERE dp.Custodian Is Not Null