Question

我有一个查询，它是另外3个comples查询的联合。有些事情如下

SELECT 'type_one' as typename, typeid, typetitle from abc, def
UNION
SELECT 'type_two' as typename, typeid, typetitle from xyz, pqr
UNION
SELECT 'type_three' as typename, typeid, typetitle from mno, ijk
order by date desc

以上查询说返回15条记录，按日期desc排序。我想用＆＃39; type_two＆＃39;来获取记录。并且最近的日期始终为第一行（可能有多行＆＃39; type_two＆＃39;），然后获取按日期desc排序的其余记录。任何人都可以指出在Oracle中这样做的方法吗？谢谢

Answer 1

使用CASE为所需列赋予不同的权重

SELECT 'type_one' as typename, typeid, typetitle from abc, def
UNION
SELECT 'type_two' as typename, typeid, typetitle from xyz, pqr
UNION
SELECT 'type_three' as typename, typeid, typetitle from mno, ijk
order by CASE WHEN typename='type_two' THEN 0 ELSE 1 END,date desc

Oracle从查询联合中获得最高排名

1 个答案: