Question

如何通过firstname和lastname显示重复的行grupe但是在不同的行中？

我有下一个代码：

SELECT    LASTname, FIRSTname, COUNT(*) AS dupes  
FROM       TCPD_PERSONEL
GROUP BY FIRSTNAME, LASTNAME, 
HAVING      (COUNT(*) > 1);

当我运行时出现：

lastname   firstname    dupes
Ion          Alin         2

但我希望看起来像这样：

lastname  firstname      email 
Ion         Alin        alin@yahoo
Ion         Alin        ion@yahoo

Answer 1

试试这个

SELECT t1.LASTname,t1.FIRSTname,t1.email from TCPD_PERSONEL t1 inner join
(
SELECT    LASTname, FIRSTname, COUNT(*) AS dupes  
FROM       TCPD_PERSONEL
GROUP BY FIRSTNAME, LASTNAME, 
HAVING      (COUNT(*) > 1)
) t2 on t1.LASTname=t2.LASTname and t1.FIRSTname=t2.FIRSTname;

Answer 2

使用分析函数：

SELECT p.*
FROM (SELECT p.*, COUNT(*) OVER (PARTITION BY FIRSTNAME, LASTNAME) as cnt  
      FROM TCPD_PERSONEL p
     ) p
WHERE cnt >= 2;

编辑：

如果行没有完全重复（即电子邮件不同），那么以下可能是最有效的方法：

select p.*
from TCPD_PERSONEL p
where exists (select 1
              from TCPD_PERSONEL p2
              where p2.firstname = p.firstname and p2.lastname = p.lastname and
                    p2.email <> p.email
             );

为了提高性能，您需要TCPD_PERSONEL(lastname, firstname, email)上的索引。

Answer 3

您需要再次使用同一个表加入该查询：

SELECT * FROM TCPD_PERSONEL 
INNER JOIN
(
SELECT    LASTname, FIRSTname, COUNT(*) AS dupes  
FROM       TCPD_PERSONEL
GROUP BY FIRSTNAME, LASTNAME
HAVING      (COUNT(*) > 1)
) x
ON x.LASTname = TCPD_PERSONEL.LASTname AND
x.FIRSTname = TCPD_PERSONEL.FIRSTname;

Answer 4

试试这个：

 SELECT * FROM tblInfo INNER JOIN (           
 SELECT    firstname, lastname, COUNT(*) AS temp  
 FROM       tblInfo
 GROUP BY lastname, firstname
 HAVING      (COUNT(*) > 1)
 ) x
 ON x. firstname = tblInfo. firstname AND
 x. lastname = tblInfo. lastname;

将'tblInfo'替换为'TCPD_PERSONEL'

Answer 5

查看您的代码，我认为Distinct是您的最佳选择。

SELECT  DISTINCT  LASTname, FIRSTname,email 
FROM    TCPD_PERSONEL

我如何显示重复的行？

5 个答案: