指令条件是否检查双记录

Question

我有这张桌子：

我如何编写指令if，它将检查同时存储的记录（在我的表中是列created_at）。 例如：

if(created_at for record where key(it's column)='stan' it is the same as created_at for key='stan_key' {
    return records where key='stan'
}

Answer 1

有几种选择。这是使用exists的版本：

select * 
from yourtable y1
where y1.key = 'stan' and exists (
    select 1
    from yourtable y2
    where y2.key = 'stan_key' and y1.created_at = y2.created_at)