SQL无法绑定多部分标识符

我得到以下错误

味精4104，第16级，状态1，第13行
无法绑定多部分标识符“OCS2.PackageType”

当我尝试多次绑定到一张表时，我看不出有什么问题，有人能帮忙吗

use osdp068a

select 
    AU1.UserName As XPSubmittedBy, PD.RegionName As XPRequestingRegion, 
    PD.BusinessGrpName As XPBusinessGroup, AU2.UserName As XPAppRequesterName, 
    AU3.UserName As XPAppOwner, AU4.UserName As XPUATOwner,
    AU5.UserName As W7SubmittedBy, PD.RegionName As W7RequestingRegion, 
    PD.BusinessGrpName As W7BusinessGroup, AU6.UserName As W7AppRequesterName, 
    AU7.UserName As W7AppOwner, AU8.UserName As W7UATOwner,
    PD.PackageCode, SUBSTRING(PD.PackageCode,6,6) AS Application_Packagecode_Version, 
    PD.LangCode, PD.LicencingMethod,
    OSC1.PackageType As PackageTypeXP, PD.InstallFilename As XPInstallInstructions, 
    PD.ReadMeFilename As XPReadMe,
    OCS2.PackageType As PackageTypeW7, PD.InstallFilename As W7InstallInstructions, 
    PD.ReadMeFilename As W7ReadMe
from 
    PackageDetail PD
/*XP*/
Join 
    aspnet_Users AU1 On PD.CreatedBy = AU1.UserId
Join 
    aspnet_Users AU2 On PD.ApplicationRequesterID = AU2.UserId
Join 
    aspnet_Users AU3 On PD.ApplicationOwnerID = AU3.UserId
Join 
    aspnet_Users AU4 On PD.UATOwnerID = AU4.UserID
/*W7*/
Join 
    aspnet_Users AU5 On PD.CreatedBy = AU5.UserId
Join
    aspnet_Users AU6 On PD.ApplicationRequesterID = AU6.UserId
Join 
    aspnet_Users AU7 On PD.ApplicationOwnerID = AU7.UserId
Join 
    aspnet_Users AU8 On PD.UATOwnerID = AU8.UserID
Left Outer Join 
    Region_CertifiedForPackage RC1 On PD.ID = RC1.PackageDetail_ID
Left Outer Join 
    OS_CerifiedForPackage OSC1 On PD.ID = OSC1.PackageDetail_ID AND OSC1.OSName_Certified = 'XP'
Left Outer Join 
    OS_CerifiedForPackage OSC2 On PD.ID = OSC2.PackageDetail_ID AND OSC2.OSName_Certified = 'WIN 7'

---

左侧外部连接OS\u CerifiedForPackage**OSC2**

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您正在尝试访问

OCS2

。只是一个简单的打字错误：）

我希望我有一双锐利的眼睛，只要按Ctrl+F；）哇，太尴尬了，看了很久了！谢谢，没问题。如果你已经半个小时没有盯着一个问题看了，只是发现它是一个打字错误，那么你就不是一个真正的开发人员：）