mysql - 为什么这个 SQL 代码会给出错误 1066（不是唯一的表/别名：'customer'）？

Question

为什么下面的 MySQL 查询会出错1066 (Not unique table/alias: 'customer')？

SELECT customer.id, customer.firstName, account.id
FROM customer, account
INNER JOIN customer
ON customer.id = account.customerId 
ORDER BY customer.id

Answer 1

您在声明中customer 两次列出了该表FROM。这是固定版本：

SELECT customer.id, customer.firstName, account.id
FROM account
INNER JOIN customer
ON customer.id = account.customerId
ORDER BY customer.id