Oracle query and aggregate function

Question

I have table name employee_1 suppose in oracle. If the mobile_no and sim_no is same i want select maximum start_date. I have tried , but no success. Please help The employee_1 t

Answer 1

NOTE: Your definition, example data and expected result are not consistent. See that you include in the result the line:

1111111111  1111111112  11/10/2017 21:02:44 13/10/2017 21:02:44

where the Mobile and SIM numbers are different.

Still, try this:

EDIT: TOP 1 was replaced with LIMIT 1 (Oracle).

SELECT LIMIT 1 Mobine_No , Sim_No , Start_Date , End_Date
  FROM YourTable
 WHERE Mobine_No = Sim_No 
ORDER BY Start_Date DESC ;

Alternative:

SELECT Mobine_No , Sim_No , MAX(Start_Date) , End_Date
  FROM YourTable

Answer 2

Try this, hopefully, it fulfills your requirement.

select mobile_no,sim_no,start_date,end_date from(
select mobile_no,sim_no,start_date,end_date,rank() over(partition by mobile_no,sim_no order by start_date desc) rn from employee_1)s
where rn=1