Question

我在unpivot sql语句中面临问题，下面是表格如下：

ID  A0001       A0002      A0003
==  =========== ========== ==========
S1  100         200        300 
S2  321         451        234
S3  0           111        222

我想转动A0001，A0002和A0003。为HEADER，SEQUENCE AND DATA创建3个列。下面是我想要的表格：

ID  HEADER      SEQUENCE     DATA
==  ==========  ===========  =======
S1  A0001       1            100 
S1  A0001       2            200
S1  A0001       3            300
S2  A0002       1            321
S2  A0002       2            451
S2  A0002       3            234
S3  A0003       1            111
S3  A0003       2            222

下面是我试过的sql语句：

SELECT ID,DATA FROM
(SELECT ID,A0001,A0002,A0003 FROM STG.TABLE_A)
UNPIVOT
(DATA FOR B IN (A0001,A0002,A0003)) C

我写的SQL只允许在数据透视后显示数据，对于HEADER和SEQUENCE字段我不知道怎么写

其次，我还要筛选出是否有任何数据透视表列将被过滤掉。例如，ID = S3，A0001为0，因此过滤零并且只获得大于零的其他字段

Answer 1

您可以在如下所示应用unpivot后出现此情况 -

SELECT ID, DATA, header
  FROM (SELECT ID, A0001, A0002, A0003 FROM STG.TABLE_A) 
        UNPIVOT(DATA FOR header IN (A0001, A0002, A0003)) C
 where data <> 0

您可以使用unvipot功能，也可以在这种情况下使用union，如下所示 -

   select id, header, sequence, data
    from (select @i := if(@lastid != id, 1, $i + 1) as sequence,
           @lastid := id,
           id,
           header,
           data
      from (

            select ID, 'A0001' as Header, A0001 as DATA
              from your_table_name
             where A0001 <> 0
            union all
            select ID, 'A0002' as Header, A0002 as DATA
              from your_table_name
             where A0002 <> 0
            union all
            select ID, 'A0003' as Header, A0003 as DATA
              from your_table_name
             where A0003 <> 0
            )t_1
            ORDER BY ID, DATA
    ) t_2

SQL Unpivot表

1 个答案: