字段列表中的列'user_id'不明确

Question

我试图获取离开此评论的用户的用户信息.

使用以下代码:

SELECT username, image, user_id FROM table_users AS us
JOIN table_reviews AS re
ON re.user_id = us.user_id
WHERE us.user_id = 1 AND
re.review_id= 1

我收到错误:

字段列表中的列'user_id'不明确

这是什么意思？

Answer 1

这意味着查询中的两个表都有列user_id.

您需要在SELECT语句中指定要获取的那个 SELECT username, image, re.user_id

Answer 2

列user_id是在两个table_reviews,table_users 表中.

您还需要指定具有表别名的列.

SELECT username, image, us.user_id FROM table_users AS us
JOIN table_reviews AS re
ON re.user_id = us.user_id
WHERE us.user_id = 1 AND
re.review_id= 1

Answer 3

这意味着列 user_id 位于两个表中，即table_reviews, table_users

尝试这样：

SELECT username, image, us.user_id    //or re.user_id
FROM table_users AS us
JOIN table_reviews AS re
ON re.user_id = us.user_id
WHERE us.user_id = 1 AND
re.review_id= 1