Question

我遇到以下LINQ查询的问题，该问题在帖子标题中引发了异常：

Dim test = From Match In _
           (From Load In dtContacts _
           Group Join Siebel In dtSiebel _
           On Load("Email") Equals Siebel("EMAIL_ADDRESS") _
           Into g = Group _
           From LoadResults In g.DefaultIfEmpty _
           Where Not LoadResults Is Nothing _
           Select Email_Address = Load.Field(Of String)("Email"), _
                  Load_Account_Number = Load.Field(Of String)("AccountNum")) _
           Group Join Acct In dtSiebel _
           On Match.Email_Address Equals Acct("EMAIL_ADDRESS") _
                And Not Match.Load_Account_Number Equals Acct("ACCOUNT_NUMBER") _
           Into h = Group _
           From MatchResults In h.DefaultIfEmpty _
           Where Not MatchResults Is Nothing _
           Select Contact_Row_ID = MatchResults.Field(Of String)("CONTACT_ROW_ID"), _
                  Match.Email_Address, _
                  Match.Load_Account_Number, _
                  Account_Num_Chk = MatchResults.Field(Of String)("ACCOUNT_NUMBER")

罪魁祸首就是这条线：

And Not Match.Load_Account_Number Equals Acct("ACCOUNT_NUMBER")

对我来说没有意义的是，如果我删除'Not'子句（我用于另一个用例），其余的查询保持不变，我得到的预期结果没有任何异常。这有什么问题？

Answer 1

你可以尝试

And Also Not Match.Load_Account_Number Equals Acct("ACCOUNT_NUMBER")

LINQ查询抛出'从字符串转换为类型'Long'无效'错误

1 个答案: