Mysql 如何修剪SQL并仍然在两个不同字段中查找具有重复数据的记录？

基本上，我正试图根据电话号码在数据库中找到所有可能的重复项。我的SQL很难看，而且需要很长时间，因为所有的选择。我如何改进它并仍然获得所有可能的副本

MySQL 5.5架构设置：

create table contacts (id int, name varchar(255), phone1 varchar(255), phone2 varchar (255));
insert into contacts (id, name, phone1, phone2) values(1, 'abe', 111, 122);
insert into contacts (id, name, phone1, phone2) values(2, 'abe', 111, 133);
insert into contacts (id, name, phone1, phone2) values(3, 'bob', 211, 222);
insert into contacts (id, name, phone1, phone2) values(4, 'carol', 233, 222);
insert into contacts (id, name, phone1, phone2) values(5, 'david', 311, 322);
insert into contacts (id, name, phone1, phone2) values(6, 'eve', 333, 311);
insert into contacts (id, name, phone1, phone2) values(7, 'fiona', 411, 422);
insert into contacts (id, name, phone1, phone2) values(8, 'gabe', 422, 433);
insert into contacts (id, name, phone1, phone2) values(9, 'harold', 511, 511);

SELECT id, name, phone1, phone2 FROM contacts
        WHERE (phone1 IN (SELECT phone1 FROM contacts GROUP BY phone1 HAVING count(phone1) > 1))
        OR (phone2 IN (SELECT phone2 FROM contacts GROUP BY phone2 HAVING count(phone2) > 1))
        OR (phone1 IN (SELECT phone2 FROM contacts))
        OR (phone2 IN (SELECT phone1 FROM contacts))
        ORDER BY phone1

查询1：

create table contacts (id int, name varchar(255), phone1 varchar(255), phone2 varchar (255));
insert into contacts (id, name, phone1, phone2) values(1, 'abe', 111, 122);
insert into contacts (id, name, phone1, phone2) values(2, 'abe', 111, 133);
insert into contacts (id, name, phone1, phone2) values(3, 'bob', 211, 222);
insert into contacts (id, name, phone1, phone2) values(4, 'carol', 233, 222);
insert into contacts (id, name, phone1, phone2) values(5, 'david', 311, 322);
insert into contacts (id, name, phone1, phone2) values(6, 'eve', 333, 311);
insert into contacts (id, name, phone1, phone2) values(7, 'fiona', 411, 422);
insert into contacts (id, name, phone1, phone2) values(8, 'gabe', 422, 433);
insert into contacts (id, name, phone1, phone2) values(9, 'harold', 511, 511);

SELECT id, name, phone1, phone2 FROM contacts
        WHERE (phone1 IN (SELECT phone1 FROM contacts GROUP BY phone1 HAVING count(phone1) > 1))
        OR (phone2 IN (SELECT phone2 FROM contacts GROUP BY phone2 HAVING count(phone2) > 1))
        OR (phone1 IN (SELECT phone2 FROM contacts))
        OR (phone2 IN (SELECT phone1 FROM contacts))
        ORDER BY phone1

： |id |姓名|电话1 |电话2| |----|--------|--------|--------| |1 | abe | 111 | 122| |2 |安倍| 111 | 133| |3 |鲍勃| 211 | 222| |4 |卡罗尔| 233 | 222| |5 |大卫| 311 | 322| |6 |夏娃| 333 | 311| （7）菲奥娜（411）×422 |8 | gabe | 422 | 433| |9 |哈罗德| 511 | 511 |

试试这个

SELECT c1.id, c1.name, c1.phone1, c1.phone2 
FROM contacts AS c1
INNER JOIN (
    SELECT id, phone1, phone2
    FROM contacts
) AS c2 ON (c1.id <> c2.id AND (c1.phone1 = c2.phone1 OR c1.phone2 = c2.phone2))
GROUP BY c1.id
ORDER BY c1.phone1

---

是的，所有的箱子都有，而且速度很快！非常感谢你！我已经15年没有上数据库课了。“在（phone1）和（phone2）上放置索引”是什么意思？我是否需要将c2前缀添加到内部联接选择中的字段？实际上，这不起作用，它还将唯一的phone1或phone2拉入结果抱歉。。但是，关于“单一性”，问题中没有任何内容。你说你需要重新组织你的查询，也许可以加快速度。是的，它会给你所有的副本。你是什么意思？这没道理。请添加更多详细信息我非常感谢您的帮助，M0RTIS。这应该表明，即使是“ivan”联系人也被拉入结果中，即使他的手机不是其他任何人的手机的复制品。这才是真正的重点-尝试找到所有的重复-没有单一的实例，尽可能少的遍历。没有，但这很好。谢谢你的努力。我得把数据库设计书从存储器里挖出来。我在网上找过其他地方，只是没有用同样的方法来比较一个记录中的一个字段，并将其与另一个记录中的不同字段进行比较，如果两个字段相同，则抓取它们-哦，好吧，祝你好运！