php - 使用where子句MYSQL获取空列

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How do I check if a column is empty or null in MySQL?
                                
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我正在创建一个表，我想在其中显示一栏为空的数据。

我尝试了一切，但似乎无济于事

$sql = "SELECT * from tblleaves where empid=:eid and EndKm is NULL order by PostingDate desc";

换句话说，我想获取endkm列为空或仅包含空格的数据。

如果我删除EndKm为NULL，则对我来说一切正常。

最佳答案

尝试SELECT * from tblleaves where empid=:eid and (EndKm IS NULL or TRIM(EndKm) = '') order by PostingDate desc