C＃Linq查询，其中表A列不相等/没有数学表B列联接

Question

I have an issue with ac# linq query where I use the != operator, it works well in SQL but when I write the same query in C# it returns a different result, which is the correct way to the the results where table a column doesn't match table b column. Please see my sql query below and then my c# query.

SELECT tba.ID,fa.accountnumber,tba.Account_Number,fa.new_legalname,tba.Legal_Name,fa.new_deliverystatusname, fa.new_deliverystatus,tba.Delivery_Charge
      FROM [CRM_Embrace_Integration].[dbo].[CRM_Tarsus_Debtors_Accounts] tba
      inner join CRM_MBT_GROUP.dbo.FilteredAccount fa
      ON fa.accountnumber collate database_default   = tba.Account_Number
      where fa.new_legalname collate database_default != tba.Legal_Name

and the Linq query looks like this

var sqlJoinQuery = from accCRM in todaysCRMAccounts
                                   join accSQL in todaysCRMViewAccounts
                                   on accCRM.Account_Number equals accSQL.accountnumber
                                   where accCRM.Legal_Name != accSQL.new_legalname
                                   select new { accCRM.Legal_Name, accSQL.new_legalname };

The SQL query returns the correct result as I want where legal_name(table A) is not equals to legal_name(table B) is the other table.

The Linq query return incorrect result, please assist.

Answer 1

I suggest to try the following Linq as you want the data that aren't in table 2:

var result1 = (from m in db1.Table1
               select m).ToList();

var result2 = (from m in db2.Table2
               select m).ToList(); 

var finalResult = (from m in result1
                   where !(from k in result2
                   select k.Id).Contains(m.Id)
                   select m).ToList();

The above will return that aren't in Table2. I hope, this is what you wanted.

Answer 2

Your SQL shows you asking for where they are equal. The LINQ shows you asking for when they are not equal.