Mysql多连接语法错误

Question

我是mysql的新手,我一直遇到这个查询的问题.

考虑这个查询:

SELECT a.group_message_id, a.scheduled_date, b.message, c.phone_number, d.group_name
    FROM schedule AS a
    JOIN group_message AS b ON a.group_message_id = b.id,
    JOIN phonenumber AS c ON c.id = a.phonenumber_id,
    JOIN group_table AS d ON d.group_id = a.group_id
    WHERE a.status = 'unsent'

并且此错误消息:

您的SQL语法有错误; 查看与您的MySQL服务器版本对应的手册,以便在'JOIN phonenumber AS c ON c.id = a.phonenumber_id,JOIN group_table AS d'附近使用正确的语法

我需要帮助解决该陈述的实际错误.如果你能告诉我其他和"正确"的做法,我也会非常感激.

最后,如果没有足够的时间,是否有一个有效的资源,我至少可以从mysql的基础知识中学习.请分享.

Answer 1

删除连接语句上的逗号,

JOIN group_message AS b ON a.group_message_id = b.id, -- <<== HERE
JOIN phonenumber AS c ON c.id = a.phonenumber_id,     -- <<== HERE
JOIN group_table AS d ON d.group_id = a.group_id

最终查询,

SELECT  a.group_message_id, 
        a.scheduled_date, 
        b.message, 
        c.phone_number, 
        d.group_name
FROM    schedule AS a
        JOIN group_message AS b 
            ON a.group_message_id = b.id
        JOIN phonenumber AS c 
            ON c.id = a.phonenumber_id
        JOIN group_table AS d 
            ON d.group_id = a.group_id
WHERE   a.status = 'unsent'