如何在 Oracle 数据库中划分查询结果中的列

Question

想要动态拆分查询结果中的列，我该怎么做？ 我有三个表并连接 them.to 获得所需的列。

select distinct t1.sal,t1.cat,t2.id,t3.shop 
from t_table1 t1,
t_table2 t2,
t_table3 t3,
where t1.sno=t2.sno AND
t2.cat=t3.cat
t3.dept_no=t3.dept_no
**output:**
t1.sal  t1.cat  t2.id  t3.shop  
1900    34R5     10     dense    
1900    34r5     10     SVM
1900    34r5     10     bpo
2345    3ER4     11     kpo
2345    3ER4     11     infra
12345   34F4     12     const
**desired output:**
t1.sal  t1.cat  t1.tin  t2.id  t3.shop_1   t3.shop_2  t3.shop_3 
1900    34r5   23456       10     dense       svm         bpo
2345    3er4   6543        11      kpo        infra       null
12345   34f4   34556       12      const       null       null

Answer 1

使用PIVOT和ROW_NUMBER分析函数：

SQL 小提琴

Oracle 11g R2 架构设置：

CREATE TABLE your_query_result (sal, cat, id, shop ) AS
SELECT 1900,   '34R5',   10,   'dense' FROM DUAL UNION ALL
SELECT 1900,   '34r5',   10,   'SVM' FROM DUAL UNION ALL
SELECT 1900,   '34r5',   10,   'bpo' FROM DUAL UNION ALL
SELECT 2345,   '3ER4',   11,   'kpo' FROM DUAL UNION ALL
SELECT 2345,   '3ER4',   11,   'infra' FROM DUAL UNION ALL
SELECT 12345,  '34F4',   12,   'const' FROM DUAL;

查询 1：

SELECT sal,
cat,
id,
"1_SHOP" AS shop_1,
"2_SHOP" AS shop_2,
"3_SHOP" AS shop_3
FROM   (
SELECT r.*,
ROW_NUMBER() OVER (
PARTITION BY sal, cat, id
ORDER BY shop
) AS rn
FROM   (
SELECT * FROM your_query_result
) r
)
PIVOT (
MAX( shop ) AS shop
FOR rn IN ( 1, 2, 3 )
)

结果：

|   SAL |  CAT | ID | SHOP_1 | SHOP_2 | SHOP_3 |
|-------|------|----|--------|--------|--------|
|  1900 | 34R5 | 10 |  dense | (null) | (null) |
|  1900 | 34r5 | 10 |    SVM |    bpo | (null) |
|  2345 | 3ER4 | 11 |  infra |    kpo | (null) |
| 12345 | 34F4 | 12 |  const | (null) | (null) |

如果您希望第一行和第二行在同一行上，则只需将CAT列更改为小写，然后再生成ROW_NUMBER并PIVOTing。