SQL Select with Len - Conversion失败吗？

Question

这是我的问题：

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

当我运行它时，我得到一个错误“转换失败，当转换nvarchar值'XXX‘到数据类型int”(xxx是我必须替换的实际值)。有人能帮帮忙吗？Ps。我希望语句在代码块中是正确的。显然，我不明白如何正确地粘贴代码。

谢谢!

Answer 1

不要紧。我不得不去掉修剪：

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