Mysql SQL查询未按预期工作|重复和错误结果

嗨，伙计们

好的，我正在编写这段代码

        SELECT 
                current.name, 
                current.status, 
                current.votes,
                current.info, 
                current.votes_required, 
                current.sid as sid,
                current.previous_required,
                previous.sid as psid,
                previous.status as status
            FROM
                systems as current
            INNER JOIN
                systems as previous
            WHERE
                (previous.status = 1 and current.previous_required = previous.status)
                OR
                (current.previous_required = 0)
            '

理想情况下，我希望显示结果，其中previous_required==0或previous_required的状态==1。然而，出于某种原因，我要么从搜索中得到三倍的结果，例如重复的结果，要么第一个结果只有一个结果

---

我敢肯定我知道我把事情搞砸了，要么是内部连接，要么是or语句。但我似乎无法将其确定下来并解决问题。任何输入都将不胜感激。

看起来您需要以某种方式将当前记录链接到以前的记录。您的系统表是否有类似于previous_sid的内容，它将当前记录链接回上一条记录？如果是这样，你需要在你的内部连接中使用它。比如：

FROM 
    systems AS current
INNER JOIN
    systems AS previous on current.previous_sid = previous.sid

---

您需要将条件从要加入的位置移动

    SELECT 
            current.name, 
            current.status, 
            current.votes,
            current.info, 
            current.votes_required, 
            current.sid as sid,
            current.previous_required,
            previous.sid as psid,
            previous.status as status
        FROM
            systems as current
        INNER JOIN
            systems as previous
          ON
            (previous.status = 1 and current.previous_required = previous.status)
            OR
            (current.previous_required = 0)

---

这解决了主要问题，谢谢。我仍然会得到重复的条目，但我只是使用GROUPBY sid来解决这个问题，没什么大不了的。