Question

我在表格中有一个PromoID字段。我需要弄清楚如何显示前6个字符相同的所有记录：

PromoID
=======
100001
100001A
100001B
101001
100002
100002A

我希望从上面看到的结果是：

PromoID
=======
100001
100001A
100001B
100002
100002A

101001被删除，因为它没有另一个带有“101001”前缀的记录。

由于

Answer 1

SELECT PromoID
FROM YourTable A
WHERE EXISTS(SELECT LEFT(PromoID,6)
             FROM YourTable
             WHERE LEFT(PromoID,6) = LEFT(A.PromoID,6)
             GROUP BY LEFT(PromoID,6)
             HAVING COUNT(*) > 1)

结果如下：

╔═════════╗
║ PromoID ║
╠═════════╣
║ 100001  ║
║ 100001A ║
║ 100001B ║
║ 100002  ║
║ 100002A ║
╚═════════╝

Here is一个带有演示的方形小说。

Answer 2

如果您使用的是SQL Server 2005或更高版本，这应该对您有用：

SELECT PromoID
FROM (
  SELECT *, COUNT(*) OVER (PARTITION BY LEFT(PromoID, 6)) AS cnt
  FROM atable
) s
WHERE cnt > 1
;

您也可以尝试此at SQL Fiddle。

Answer 3

您也可以使用子选择

来执行此操作

SELECT PromoID FROM YourTable
WHERE LEFT(PromoID,6) IN
(
SELECT LEFT(PromoID,6) 
FROM YourTable 
Group By LEFT(PromoID, 6)
HAVING COUNT(*) > 1
)

Fiddle Demo

Answer 4

您可以使用公用表表达式执行此操作：

WITH CTE (Prefix) AS
  (select LEFT(PromoId, 6) from Foo GROUP BY LEFT(PromoId, 6) HAVING COUNT(1) > 1)
SELECT PromoId FROM Foo
INNER JOIN CTE ON LEFT(PromoId, 6) = CTE.Prefix;

Fiddle

Answer 5

内部查询列出要拒绝的所有PromoID。外部查询采用所有PromoID减去被拒绝的内容：

SELECT *
  FROM table1
 WHERE PromoID not in (
    SELECT t1.PromoID
      FROM table1 t1
    LEFT JOIN table1 t2 ON t1.PromoID != t2.PromoID
          AND left(t1.PromoID, 6) = left(t2.PromoID, 6)
     WHERE t2.PromoID IS NULL
 )

SQL Fiddle

返回字段具有相同前缀的所有记录

5 个答案: