选择where（列定义为）或count（*）＆gt; 50这样的东西

Question

这个mysql查询给了我未知的列错误

SELECT count(vs.no) AS no_of_vocabs, level, owner_no FROM vocab_stats as vs 
LEFT JOIN (SELECT no, level FROM mst_words) mw ON mw.no = vs.vocab_no 
WHERE owner_no = 6 AND correct > 0 AND vs.no_of_vocabs > 50 
group by owner_no, level

我该如何解决这个问题？

Answer 1

您应该使用HAVING（请参阅documentation on SELECT）

SELECT COUNT(vs.no), level, owner_no FROM vocab_stats as vs 
LEFT JOIN (SELECT no, level FROM mst_words) mw ON mw.no = vs.vocab_no 
WHERE owner_no = 6 AND correct > 0
GROUP BY owner_no, level
HAVING COUNT(vs.no) > 50

Answer 2

我猜测未知列是vs.no_of_vocabs，因为您定义了no_of_vocabs，但它不是vs / vocab_stats表的一部分，它只是查询。从vs移除vs.no_of_vocabs，应该修复它。

如果这不是问题，我们需要查看错误消息。