Sql 根据条件删除重复行的oracle查询
我有如下表所示的数据Sql 根据条件删除重复行的oracle查询,sql,oracle,join,Sql,Oracle,Join,我有如下表所示的数据 +------+----------+----------+ | type | date1 | date2 | +------+----------+----------+ | IT1 | 05/01/15 | 08/01/15 | | IT1 | 05/01/15 | | | IT1 | 04/01/15 | | | IT1 | | 03/02/15 | | IT1 | 06/01/15 | 03
+------+----------+----------+
| type | date1 | date2 |
+------+----------+----------+
| IT1 | 05/01/15 | 08/01/15 |
| IT1 | 05/01/15 | |
| IT1 | 04/01/15 | |
| IT1 | | 03/02/15 |
| IT1 | 06/01/15 | 03/02/15 |
| IT1 | | 04/02/15 |
| IT2 | 05/01/15 | |
| IT2 | 05/01/15 | 04/01/15 |
| IT2 | 03/01/15 | |
| IT2 | | 09/01/15 |
+------+----------+----------+
我需要通过删除重复项来获取行,结果如下
+------+----------+----------+
| type | date1 | date2 |
+------+----------+----------+
| IT1 | 05/01/15 | 08/01/15 |
| IT1 | 04/01/15 | |
| IT1 | 06/01/15 | 03/02/15 |
| IT1 | | 04/02/15 |
| IT2 | 05/01/15 | 04/01/15 |
| IT2 | 03/01/15 | |
| IT2 | | 09/01/15 |
+------+----------+----------+
对于特殊类型
select *
from table1 t1
WHERE
"date2" IS NOT NULL
AND
"date1" IS NOT NULL
OR
"date2" IS NULL
AND NOT EXISTS (
SELECT 1 FROM table1 t2
WHERE t1."type" = t2."type"
AND t1."date1" = t2."date1"
AND t2."date2" IS NOT NULL
)
OR
"date1" IS NULL
AND NOT EXISTS(
SELECT 1 FROM table1 t2
WHERE t1."type" = t2."type"
AND t1."date2" = t2."date2"
AND t2."date1" IS NOT NULL
)
演示: