Php mysql语句中的条件

我正在尝试在mysql查询中写入一个条件：

    SELECT g.* FROM groups AS g
            JOIN users AS u 
            ON u.user_posts >= g.post_min
            AND u.user_posts <= g.post_max
            AND u.points >= g.point_min
            AND u.points <= g.point_max
            AND u.uid = "'.$uid.'" 

从组中选择g.*作为g
以u的身份加入用户
在u.user_posts>=g.post_min上
和u.user_posts=g.point_min
和u.points
$sql='选择g.id，g.point\u金额
来自组作为g
以u的身份加入用户
在u.user_posts>=g.post_min上
和（u.user_posts=g.point_min
和（u.points用OR连接它们；跳过条件为真，或者术语不能跳过：

(g.post_max = 0) OR (u.user_posts <= g.post_max)
(g.point_max = 0) OR (u.points <= g.point_max)

（g.post\u max=0）或（u.user\u posts）可能有帮助
(g.post_max = 0) OR (u.user_posts <= g.post_max)
(g.point_max = 0) OR (u.points <= g.point_max)

$sql = 'SELECT g.id,g.point_amount
        FROM groups AS g
        JOIN users AS u 
        ON u.user_posts >= g.post_min
        AND u.points >= g.point_min
        AND ((g.post_max = 0) OR (u.user_posts <= g.post_max))
        AND ((g.point_max = 0) OR (u.points <= g.point_max))
        AND u.uid = "'.$uid.'" 
        LIMIT 1';