Question

我正在尝试从“发货人”表中选择“用户”表中出现“order_id”属性最多的用户。这就是我尝试过的：

SELECT users.first_name, users.email, shipments.count(order_id) 
    FROM users, shipments
    WHERE shipments.order_id = users.current_order_id
    GROUP by shipments.order_id
    ORDER by shipments.count(order_id) DESC
    LIMIT 25

但我收到的错误是：

ERROR:  schema "shipments" does not exist

有什么想法吗？

Answer 1

你正在以错误的方式做COUNT。 tableName和列名称位于COUNT（）内。或者你可以在这种情况下做COUNT（*）：

SELECT users.first_name, users.email, count(shipments.order_id) 
FROM users, shipments
WHERE shipments.order_id = users.current_order_id
GROUP by users.first_name, users.email
ORDER by count(shipments.order_id) DESC
LIMIT 25

此外，您应该对您选择的不是聚合函数的列执行GROUP BY。

错误：架构“x”不存在

1 个答案: