刪除倒置的重複項 - SQL Server

Question

我想刪除重複項，但它們不顯示爲重複項。 有沒有一個查詢來幫助消除這一點，只留下一個背後？

Answer 1

像這樣的事情會組排序的順序行由兩個領域，刪除除了一個以外 我假設這兩個字段必須匹配，並且您有一個名爲TableId的主鍵。

DELETE 
    T 
FROM 
    [Table] T 
JOIN (
    SELECT 
     TableId, 
     [Name], 
     ROW_NUMBER() OVER (PARTITION BY [Name] ORDER BY TableId DESC) RowId 
    FROM (
     SELECT 
      TableId, 
      Reg_Num + '|' + Driver_Name AS [Name] 
     FROM 
      [Table] 
     WHERE 
      Reg_Num <= Driver_Name 
     UNION 
     SELECT 
      TableId, 
      Driver_Name + '|' + Reg_Num AS [Name] 
     FROM 
      [Table] 
     WHERE 
      Driver_Name < Reg_Num 
     ) Y 
    ) X ON 
     X.TableId = T.TableID 
WHERE 
    RowId > 1 

Answer 2

這個查詢將產生標準化的值（如果他們都VARCHAR處理），你現在可以檢查重複對

select 
    [someId], 
    case 
     when reg_num < driver_name then reg_num + driver_name 
            else driver_name + reg_num 
    end as combination