Question

我需要找到已在表格中插入两次的用户，但使用他们的名字＆amp;姓氏交换。

e.g。 Bob Smith在数据库中

firstname:Bob 
lastname:Smith
&
firstname:Smith
lastname:Bob

找到这些用户的最佳查询是什么？

服务器运行mysql。

Answer 1

Select 
  *
FROM UserTable ut
JOIN UserTable ut2 on ut2.firstname = ut.lastname and ut2.lastname = ut.firstname

Answer 2

SELECT
    firstname, lastname
FROM
    (
    SELECT firstname, lastname FROM MyTable -- WHERE firstname <> lastname
    UNION ALL
    SELECT lastname, firstname FROM MyTable -- WHERE firstname <> lastname
    ) foo
GROUP BY
   firstname, lastname
HAVING 
   COUNT(*) > 1

Answer 3

SELECT orig.firstname, orig.lastname
FROM yourtable AS orig
INNER JOIN yourtable AS dupes ON orig.firstname = dupe.lastname AND orig.lastname = dupe.firstname

基本上，在用户表上进行自联接，但仅限于发生fn / ln欺骗交换的记录。

mysql - 使用firstname / lastname交换查找重复的用户

3 个答案: