postgresql 如何匹配not null + not empty？
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How to match not null + not empty?
提问by rap-2-h
I have to do some queries on a messy database. Some columns are filled with either nullor empty string. I can do query like this:
我必须对凌乱的数据库进行一些查询。某些列填充为null空字符串或空字符串。我可以做这样的查询：
select * from a where b is not null and b <> '';
But is there a shortcut for this case? (match every "not empty" values) Something like:
但是这种情况有捷径吗？（匹配每个“非空”值）类似：
select * from a where b is filled;
回答by Clodoaldo Neto
Just:
只是：
where b <> ''
will do what you want as null <> ''is null and the row will not be returned
会做你想做的事情，因为它null <> ''是空的，并且不会返回该行
回答by Steve Smith
select * from a where COALESCE(b, '') <> '';
select * from a where COALESCE(b, '') <> '';
