Question

我在这张表中包含以下数据

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Repeat列中的值，应该再次重复该行。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疑问吗？

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)

如果您的表格保证的记录多于repeat的最大可能值，您可以删除@repeats并使用该表格。

Answer 3

我更喜欢以下方法，因为它不依赖于外部数据来使查询成功并且相当直接。我使用了Aaron Bertrand的代码来初始化数据表，但我的方法是如何重复数据 - 这种方法不需要特定的表来包含比所需的递归更多的行/不依赖于外部数据。

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;

DECLARE @maxRecursion INT;
SET @maxRecursion = (SELECT MAX(Repeat) 
                       FROM @d);    

WITH Iterator AS 
(
    SELECT 1 AS Iterations
    UNION ALL
    SELECT Iterations + 1 FROM Iterator WHERE Iterations < @maxRecursion
)

SELECT A.*
  FROM @d AS A
 RIGHT JOIN Iterator ON Iterator.Iterations <= (A.Repeat + 1)
 ORDER BY Job ASC
OPTION (MAXRECURSION 0)

干杯！

Answer 4

您可以编写将执行此查询的存储过程（作为游标），然后您可以根据需要填写新的临时表

CREATE FUNCTION [dbo].[GetRepeatJobs]()
RETURNS 
@JobsRepeatTable TABLE (JobId int, JobName nchar(10))
AS
BEGIN
DECLARE @i int
DECLARE @j int
DECLARE @JobId int
DECLARE @JobName nchar(10)

DECLARE JobsCursor CURSOR FOR (select JobId, JobName, JobRepeat from jobs)
OPEN JobsCursor
FETCH NEXT FROM JobsCursor INTO @JobId, @JobName, @i

WHILE @@FETCH_STATUS = 0
BEGIN
    SELECT @j = 0
    WHILE @j < @i
    BEGIN
        INSERT INTO @JobsRepeatTable VALUES (@JobId, @JobName)
        SELECT @j = @j+1    
    END
    FETCH NEXT FROM JobsCursor INTO @JobId, @JobName, @i
END 
RETURN 
END

适合我的作品。

根据每行中的列值复制行

4 个答案: