根据每行中的列值复制行

Question

我在这张表中有以下数据

Job    Quantity Status Repeat
1      100      OK     2
2      400      HOLD   0
3      200      HOLD   1
4      450      OK     3

根据每行的"重复"列中的值,应再次重复该行.例如,对于作业1,重复值为2,因此作业1应重复两次.

结果表应如下所示

Job    Quantity Status Repeat
1      100      OK     2
1      100      OK     2
1      100      OK     2
2      400      HOLD   0
3      200      HOLD   1
3      200      HOLD   1
4      450      OK     3
4      450      OK     3
4      450      OK     3
4      450      OK     3

有人可以帮我解决这个问题吗？

我正在使用sql server

Answer 1

这将为任何个人工作(在我的系统上)支持超过7,400次重复.如果需要更多,可以使用其他系统表或交叉连接.

DECLARE @d TABLE (Job INT, Quantity INT, Status VARCHAR(12), Repeat INT);

INSERT @d SELECT 1, 100, 'OK'  ,2
UNION ALL SELECT 2, 400, 'HOLD',0
UNION ALL SELECT 3, 200, 'HOLD',1
UNION ALL SELECT 4, 450, 'OK'  ,3;

WITH x AS 
(
  SELECT TOP (SELECT MAX(Repeat)+1 FROM @d) rn = ROW_NUMBER() 
  OVER (ORDER BY [object_id]) 
  FROM sys.all_columns 
  ORDER BY [object_id]
)
SELECT * FROM x
CROSS JOIN @d AS d
WHERE x.rn <= d.Repeat + 1
ORDER BY Job;

Answer 2

DECLARE @repeats TABLE
        (
        rn INT NOT NULL PRIMARY KEY
        );

WITH    q (rn, m) AS
        (
        SELECT  1, MAX(repeat) + 1
        FROM    jobs
        UNION ALL
        SELECT  rn + 1, m
        FROM    q
        WHERE   rn < m
        )
INSERT
INTO    @repeats
SELECT  rn
FROM    q

SELECT  j.*
FROM    jobs j
CROSS APPLY
        (
        SELECT  TOP (j.repeat + 1)
                NULL
        FROM    @repeats
        ) q (repeat)

如果你有一个表肯定有比最大可能值更多的记录repeat,你可以摆脱@repeats并使用该表.