如何從員工表中提取出'姓，名和出生日期'同樣的員工表

Question

我需要提取出名，姓和出生日期相同的記錄。 請看下面的例子。

Employeeid firstname lastname DOB 
00010   ravi  sagi  22/01/1990 
00035   ravi  sagi  22/01/1990 
00060   vasanth guptha 20/01/1987 
00115   vasanth guptha 20/01/1987 

你可以請幫忙寫下查詢。

Answer 1

試試這個：

select * 
from 
    (
    select *, 
      count(*) over(partition by firstname, lastname, DOB) as CC 
    from YourTable 
) as T 
where T.CC > 1 

Answer 2

可以JOIN將表與自身比較firstname，lastname和DOB以確保它們是相同的值，然後將employeeid是不一樣的：

select * 
from yourtable t1 
inner join yourtable t2 
    on t1.firstname = t2.firstname 
    and t1.lastname = t2.lastname 
    and t1.dob = t2.dob 
    and t1.empid != t2.empid 

以上查詢可能會顯示重複記錄，因此您可以使用以下內容（請參閱SQL Fiddle with Demo）：

select DISTINCT t1.empid, 
    t1.firstname, 
    t1.lastname, 
    t1.DOB 
from yourtable t1 
inner join yourtable t2 
    on t1.firstname = t2.firstname 
    and t1.lastname = t2.lastname 
    and t1.dob = t2.dob 
    and t1.empid != t2.empid 

或者你可以使用EXISTS（見SQL Fiddle with Demo）：

select t1.empid, 
    t1.firstname, 
    t1.lastname, 
    t1.DOB 
from yourtable t1 
where exists (SELECT * 
       FROM yourtable t2 
       WHERE t1.firstname = t2.firstname 
       and t1.lastname = t2.lastname 
       and t1.dob = t2.dob 
       and t1.empid != t2.empid)