Question

如何写进下面的问询表? 我读到了《国际红十字与红新月联会》条款中的某些地方。这样做有什么更好的选择?

if exists (select username from tbl_stats_assigned where username =  abc  )
    select 1 as uname
else
    select 0 as uname

Answer 1

Just do it the standard SQL way:

select exists(
    select 1
    from tbl_stats_assigned
    where username =  abc 
);

当然,假设你的<代码>1和0实际上是 b(QL所代表的是一、零,就像MySQL)。

That should work in any SQL database and some even have special optimizations to support that idiom.