Question

我的数据看起来像这样

    col1; col2; col3; col4; sort; desc; levels
    1     1     1     1     10    ab     null
    1     1     1     2     20    c      1
    1     1     1     3     30    d      null
    1     1     1     4     40    e      null
    1     1     1     5     50    fg     1
    1     1     1     6     60    hij    1
    1     1     1     7     70    k      1

所需的输出如下所示

    col1; col2; col3; col4; desc; addDesc
    1     1     1      1     ab   null
    1     1     1      2     c    ab
    1     1     1      3     d    null
    1     1     1      4     e    null
    1     1     1      5     fg   e
    1     1     1      6     hij  e
    1     1     1      7     k    e

逻辑是每当列LEVELS不为空时，从LECELS为空的先前DESC获取值。我希望你们明白这一点！

提前谢谢大家！

Answer 1

您可以使用OUTER APPLY：

SELECT  t1.col1,
        t1.col2,
        t1.col3,
        t1.col4,
        t1.[desc],
        CASE
            WHEN t1.levels IS NOT NULL THEN t2.[desc]
        END [addDesc]
FROM dbo.YourTable t1
OUTER APPLY (SELECT TOP 1 [desc]
             FROM dbo.YourTable
             WHERE levels IS NULL
             AND sort < t1.sort
             ORDER BY sort DESC) t2;

从具有条件的先前行中选择数据

1 个答案: