MYSQL对不为空的行进行计数

我只需要数那些不是空的行。谢谢

SELECT component,count(comp_details) FROM table GROUP BY component

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尝试这样做：根据需求添加where子句

SELECT component,count(comp_details) FROM table GROUP BY component

SELECT component,count(comp_details) FROM table where comp_details is not null and comp_details != "" GROUP BY component

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虽然您希望有条件地计数，但您的查询没有任何

WHERE

部分

SELECT component,count(comp_details) FROM table GROUP BY component

SELECT component,count(comp_details) 
FROM table 
WHERE IFNULL(component, '') != ''
GROUP BY component

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comp_details是否可以为null？它不应该是

comp_details不为null且comp_details！=“

？