SQL:带有"存在"的case-when语句

Question

我希望能够设置添加一个回答问题的字段"对于此记录中的值,该值是否满足另一个表中的某些条件？".我想我会尝试case-when用exists,但Teradata的(我DBMS)不喜欢它.有什么建议？

select foo,
   (case when exists (select x.foo
                      from somedb x
                      where x.bar > 0)
    then '1' else '0' end) as MyFlag

from mydb

Answer 1

看起来你错过END了CASE声明？

select foo,
   (case when exists (select x.foo
                      from somedb x
                      where x.bar > 0)
    then '1' else '0' END) as MyFlag

from mydb