選擇where（列定義為）或count（*）> 50之類的東西

Question

這個mysql查詢給了我未知的列錯誤

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

我怎樣才能解決這個問題？

Answer 1

您應該使用HAVING （請參閱SELECT上的文檔 ）

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

我想您所定義的no_of_vocabs未知列是vs.no_of_vocabs ，但它不是vs / vocab_stats表的一部分，它只是查詢的一部分。 從vs.no_of_vocabs刪除vs ，應該修復它。

如果這不是問題，我們將需要查看錯誤消息。