asp.net - LINQ 查询抛出“从字符串转换为类型 'Long' 无效”错误

Question

我遇到了以下 LINQ 查询的问题，该查询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")

罪魁祸首是这一行：

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

对我来说没有意义的是，如果我删除了 'Not' 子句（我用于另一个用例）而保留查询的其余部分不变，我会得到预期的结果而没有任何异常。这里有什么问题？

Answer 1

你可以试试

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