组查询中的 Oracle 数据透视列

Question

我有以下工作查询：

WITH pivot_data AS (
             select PSGROUP,
    PSCOLUMN as PSCOLUMN
FROM LOG_PS_STATUS
            )
    SELECT *
    FROM   pivot_data
    PIVOT (
           MAX(NULL)        --<-- pivot_clause
          FOR PSCOLUMN--<-- pivot_for_clause        
        IN  (&PS_COLUMNS.)   --<-- pivot_in_clause         

);

它显示了预期的结果：

值：

PSGroup PSColumn
A           1
A           2
A           3
B           1
B           2
B           3
C           3

结果如下：

PSGroup(Column vertically) PSColoumn(Horizontally)

现在我想将 PSGroup 列作为一组 PSColumn，输出应该如下所示：

Answer 1

您可以使用 listagg:

WITH pivot_data(PSGroup,PSColumn) AS (
    select 'A',           1 FROM dual UNION all
    select 'A',           2 FROM dual UNION all
    select 'A',           3 FROM dual UNION all
    select 'B',           1 FROM dual UNION all
    select 'B',           2 FROM dual UNION all
    select 'B',           3 FROM dual UNION all
    select 'C',           3 FROM DUAL),

    res(PSGroup,PSColumns) as(
     SELECT PSGroup, LISTAGG(PSColumn, ' ') WITHIN GROUP (order by PSColumn)
        FROM   pivot_data
        GROUP BY PSGroup)

    select DECODE(PSColumns,NULL,PSGroup,NULL) AS PSGroup, PSColumns from(
    select PSGroup, NULL as PSColumns from res
      union all
    select PSGroup, PSColumns from res)t
      ORDER BY t.PSGroup, t.PSColumns NULLS first

另请注意，LISTAGG(PSColumn, ' ') WITHIN GROUP (order by PSColumn) 限制为 4000 个字符

组查询中的 Oracle 数据透视列

Oracle Pivot Column in group query

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