Php Mysql查询：表示子查询返回超过1行的错误

我正在尝试从两个表中进行一个复杂的查询…这是一个来自技能测验的问题

桌子

输出

-----------+------------+
| State     |  # Orders  |
+-----------+------------+
| NY        |  55        |
| CA        |  40        |
| NJ        |  33        |
| FL        |  21        |
| MO        |  12        |
+-----------+------------+

我一直在处理我的查询，它看起来像这样

select DISTINCT state, (select count(id) Orders
                        from customers
                        group by state
                        ORDER BY Orders DESC) FROM Customers

它给了我一个错误，说子查询返回的行数超过1行。请尝试以下操作：

SELECT c.state, COUNT(o.id) AS Orders 
FROM Customers c, Orders o 
WHERE o.customer_id = c.id 
GROUP BY state 
ORDER BY Orders DESC

select DISTINCT state, (select count(id) as cnt, Orders from customers group by
    state ORDER BY Orders DESC) Temp FROM Customers

子查询不是必需的。

请尝试以下操作：

SELECT c.state, COUNT(o.id) AS Orders 
FROM Customers c, Orders o 
WHERE o.customer_id = c.id 
GROUP BY state 
ORDER BY Orders DESC

SELECT `Customers`.`state`, count(`Orders`.`id`) 
as `orders FROM `Customers` 
LEFT JOIN `Orders` ON `Customers`.`id` = `Orders`.`customer_id` 
GROUP BY `Customers`.`state` 
ORDER BY `orders` DESC

select DISTINCT state, (select count(id) as cnt, Orders from customers group by
    state ORDER BY Orders DESC) Temp FROM Customers

子查询不是必需的。

请尝试以下操作：

SELECT c.state, COUNT(o.id) AS Orders 
FROM Customers c, Orders o 
WHERE o.customer_id = c.id 
GROUP BY state 
ORDER BY Orders DESC

SELECT `Customers`.`state`, count(`Orders`.`id`) 
as `orders FROM `Customers` 
LEFT JOIN `Orders` ON `Customers`.`id` = `Orders`.`customer_id` 
GROUP BY `Customers`.`state` 
ORDER BY `orders` DESC

select DISTINCT state, (select count(id) as cnt, Orders from customers group by
    state ORDER BY Orders DESC) Temp FROM Customers

试试这个：

SELECT c.state, COUNT(o.id) AS Orders 
FROM Customers c, Orders o 
WHERE o.customer_id = c.id 
GROUP BY state 
ORDER BY Orders DESC

select DISTINCT state, (select count(id) as cnt, Orders from customers group by
    state ORDER BY Orders DESC) Temp FROM Customers

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