Question

对于pubs我想将stores表中的stor_name添加到查询中，但它不起作用。

查询是：

SELECT 
    title, COALESCE(SUM(S.qty * T.price), 0) totalsale
FROM 
    titles T
LEFT JOIN
    sales S ON (S.title_id = T.title_id)
GROUP BY 
    title
ORDER BY 
    2 DESC

我需要在stor_name表格中添加store。如果我尝试像这样添加它

SELECT 
    title, COALESCE(SUM(S.qty * T.price), 0) totalsale, stores.stor_name
FROM 
    titles T
LEFT JOIN
    sales S ON (S.title_id = T.title_id)
JOIN
    stores ON (S.stor_id = stores.stor_id)
GROUP BY 
    title
HAVING 
    stores.stor_name
ORDER BY 
    2 DESC

返回的结果是错误的。

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Answer 1

您需要在GROUP BY中包含该名称或作为聚合函数的参数。类似的东西：

SELECT title, COALESCE(SUM(S.qty*T.price), 0) as totalsale, st.stor_name
FROM titles T LEFT JOIN
     sales S
     ON (S.title_id = T.title_id) JOIN
     stores st
     ON S.stor_id = st.stor_id)
GROUP BY title, st.stor_name
ORDER BY 2 desc;

或者，如果您只想要其中一个名字，那么：

SELECT title, COALESCE(SUM(S.qty*T.price), 0) as totalsale,
       MAX(st.stor_name)
FROM titles T LEFT JOIN
     sales S
     ON (S.title_id = T.title_id) JOIN
     stores st
     ON S.stor_id = st.stor_id)
GROUP BY title
ORDER BY 2 desc;

pubs数据库中stor_name的SQL查询

1 个答案: