如何将Informatica的规范化器转换转换为SQL查询?

Question

我有一个表，其中我有一个列REC_ORDER，其中有 20 次出现，如 REC_ORDER_1，REC_ORDER_2 到 REC_ORDER_20.规范化器转换后，我得到一个输出列作为REC_ORDER。我想知道如何将此规范化器转换转换为 SQL 查询。

Answer 1

您可以使用SELECT的UNPIVOT子句，如下所示：

create table demo(id number, n1 number, n2 number, n3 number, n4 number, n5 number);
insert into demo values (1, 45, 87, 96, 33, 17);
insert into demo values (2, 245, 287, 296, 233, 217);
commit;
select * from demo
unpivot (
val
for num in (
n1 as '1',
n2 as '2',
n3 as '3',
n4 as '4',
n5 as '5'
)
);

结果集如下所示：

| ID | NUM | VAL |
|----|-----|-----|
|  1 |   1 |  45 |
|  1 |   2 |  87 |
|  1 |   3 |  96 |
|  1 |   4 |  33 |
|  1 |   5 |  17 |
|  2 |   1 | 245 |
|  2 |   2 | 287 |
|  2 |   3 | 296 |
|  2 |   4 | 233 |
|  2 |   5 | 217 |

在 http://sqlfiddle.com/#!4/bf9cb/8/0 中看到它

Answer 2

你可以像这样创建 SQL -

SELECT occurance1.id as id, occurance1.value1 from source_table occurance1
union all  
SELECT occurance2.id as id, occurance2.value2 from source_table occurance2
union all  
SELECT occurance3.id as id, occurance3.value3 from source_table occurance3
union all  
...
SELECT occurance20.id as id, occurance20.value20 from source_table occurance20`