sql - 在 sql(oracle) 中动态包含条件

Question

我有一个查询如下

select --------
from table a
left outer join ....c
where 
(a.column='123') and (c.column='456')

我想

仅当 (c.column='456') 不为空时才包含 "(c.column='456')"

我如何在单个查询中做到这一点？还是我需要编写两个单独的查询？

我试过 (a.column='123') 和 (c.column is null)，没用

Answer 1

尝试：

select --------
from table a
left outer join ....c
where 
((a.column='123') and (c.column='456'))
or c.column is not NULL

Answer 2

尝试将检查 null 和值 456 放在同一组括号中：

select --------
from table a
left outer join ....c
where 
(a.column='123') and (c.column is not null and c.column='456')