sql - oracle sql从行到列

Question

我需要编写一条 Oracle SQL 语句将 table1 转换为 table2

 number    name    
  1         A
  1         B
  2         A
  2         E
  3         D

number  name1   name2   name3   name4
  1      A      B       
  2      A      E   
  3      D          

我尝试使用 listagg 但这给了我一列

Answer 1

除非您使用动态 SQL，否则您必须预先定义许多列。

如果您对 4 次感到满意，则可以加入该表 4 次。

或者...

WITH rankedResults AS (
    SELECT
         number
        ,name1
        ,RANK() OVER (PARTITION BY number ORDER BY name1) as rank
    FROM table1
)
WITH diagonalResults (
    SELECT
         number
        ,CASE WHEN rank = 1 THEN name1 END AS name1
        ,CASE WHEN rank = 2 THEN name1 END AS name2
        ,CASE WHEN rank = 3 THEN name1 END AS name3
        ,CASE WHEN rank = 4 THEN name1 END AS name4
    FROM rankedResults
)
SELECT
     number
    ,MAX(name1) AS name1
    ,MAX(name2) AS name2
    ,MAX(name3) AS name3
    ,MAX(name4) AS name4
FROM diagonalResults
GROUP BY number