php - mySQL 查询 - 简单的数学问题

Question

我每个人都有 2 个电话号码。有的只填写了电话，有的只填写了电话2，有的则两者都有。

我正在尝试查找具有相同电话号码的其他人，电话 = 电话、电话 = 电话 2、电话 2 = 电话、电话 2 = 电话 2

问题是，如果 Telephone1 为空，那么我现有的代码会将其与下一个具有电话号码的人匹配，无论电话或 Telephone2 是否为空。我需要在代码中添加什么。

    function getothers($tid,$criteria,$telephone,$telephone2,$elector){
                global $dbh;
                $tid = '-TID'.$tid;
                 $sql = "SELECT * FROM electors 
WHERE (telephone > 0 OR telephone2 > 0)
AND records NOT RLIKE '$tid'
AND (telephone IN ('$telephone','$telephone2') 
OR telephone2 IN ('$telephone','$telephone2')) 
AND ID != '$elector'  LIMIT 10";
                return $dbh->query($sql);
            }

Answer 1

SELECT T_el.*
FROM (electors AS T_el) LEFT JOIN (electors AS T_dup)
ON (T_el.ID!=T_dup.ID
  AND (
    (T_el.telephone IS NOT NULL AND (T_el.telephone=T_dup.telephone OR T_el.telephone=T_dup.telephone2))
    OR
    (T_el.telephone2 IS NOT NULL AND (T_el.telephone2=T_dup.telephone OR T_el.telephone2=T_dup.telephone2))
    )
)
WHERE T_dup.ID IS NOT NULL
GROUP BY T_el.ID