Question

所以，我需要帮助在子查询中做一个选择，我知道这有点基础，但我还是不能自己做。

（Reparacao =维修和lojas =商店，从葡萄牙语到英语）

我想获得每家商店的维修数量。但是我一次只能做一个商店，但我想要一个选择所有商店的查询。

我正在使用此查询：

SELECT COUNT( DISTINCT id_reparacao ) , lojas.nome
FROM reparacoes
INNER JOIN lojas ON lojas.id = 1
WHERE id_loja = lojas.id

我想要这样的东西：

SELECT COUNT( DISTINCT id_reparacao ) , lojas.nome
FROM reparacoes
INNER JOIN lojas ON lojas.id = (Select id from lojas)    //i want the id of every store
WHERE id_loja = lojas.id

Answer 1

试试这个：

无需使用子查询来获取商店的所有修复计数。您可以使用 JOIN 和 GROUP BY 轻松获得结果。

SELECT COUNT(DISTINCT id_reparacao) repairCnt, lojas.nome
FROM reparacoes
INNER JOIN lojas ON lojas.id = id_loja 
GROUP BY lojas.id

Answer 2

为什么不尝试加入ON ID：

SELECT COUNT( DISTINCT r.id_reparacao ) , lojas.nome
FROM reparacoes r
INNER JOIN lojas l ON l.id = r.id_loja;

Mysql子查询选择所有id

2 个答案: