如何选择null或零长度？

Question

我有疑问：

select text_b, id from articles where title is not null;

但是我希望显示text_b不为null且text_b的长度为＆gt;的结果。 0。 怎么做？

Answer 1

select text_b, id 
from articles 
where title is not null
  and length(text_b) > 0;

或

select text_b, id 
from articles 
where title is not null
  and text_b <> '';

或正确处理null

中的text_b值

select text_b, id 
from articles 
where title is not null
  and text_b is distinct from '';