SQL 服务器 n 次固定枢轴

Question

因此，业务人员要求我以特定方式显示数据。他们需要为特定值显示 X 列数量，如果该值不存在，则用零填充。

换句话说，我有：

而我需要的是：

我不知道我是应该用一个枢轴还是一个 CTE 和一个循环来解决这个问题...你能帮我吗？

使用 SQL Server 2008。

Answer 1

您可以使用 ROW_NUMBER 和条件聚合来执行此旋转

WITH cte
     AS (SELECT RECORD_ID,
                NUMBER,
                Row_number() OVER(PARTITION BY RECORD_ID ORDER BY NUMBER ) AS RN
         FROM   yourtable)
SELECT RECORD_ID,
       COALESCE(Max(CASE WHEN rn = 1 THEN NUMBER END),0) AS NUMBER01,
       COALESCE(Max(CASE WHEN rn = 2 THEN NUMBER END),0) AS NUMBER02,
       COALESCE(Max(CASE WHEN rn = 3 THEN NUMBER END),0) AS NUMBER03,
       COALESCE(Max(CASE WHEN rn = 4 THEN NUMBER END),0) AS NUMBER04,
       COALESCE(Max(CASE WHEN rn = 5 THEN NUMBER END),0) AS NUMBER05,
       ...
       COALESCE(Max(CASE WHEN rn = 10 THEN NUMBER END),0) AS NUMBER10
FROM   CTE
GROUP  BY RECORD_ID

动态方法

DECLARE @x        INT = 10, -- Replace it with required of columns 
        @intr     INT = 1,
        @col_list VARCHAR(8000)='',
        @sql      VARCHAR(max)=''

SET @sql = '    WITH cte
         AS (SELECT RECORD_ID,
                    NUMBER,
                    Row_number() OVER(PARTITION BY RECORD_ID ORDER BY NUMBER ) AS RN
             FROM   yourtable)
    SELECT RECORD_ID, '


/*nothing to worry about the below while loop it is just to frame the string*/
WHILE @intr <= @x
  BEGIN
      SET @col_list += 'COALESCE(Max(CASE WHEN rn = ' + Cast(@intr AS VARCHAR(50)) + ' THEN NUMBER END),0) AS NUMBER' + Cast(@intr AS VARCHAR(50)) + ','
      SET @intr += 1
  END

SET @col_list = LEFT(@col_list, Len(@col_list) - 1)
SET @sql += @col_list + ' FROM   CTE
    GROUP  BY RECORD_ID '

EXEC ( @sql )

SQL 服务器 n 次固定枢轴

SQL Server n Times Fixed Pivot

sql-server

pivot

rows

common-table-expression