select recent results for distinct columns- SQL

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Hi guys, please help

Im trying to get the grade for each car at the latest date.

Sample table:

car-index	installed_date	firebar-grade	frame-grade
CAR5	           05-Jul-12	          B	A
CAR3	           31-Jan-12	          A	A
CAR1	           05-Apr-12	          C	C
CAR1	           24-May-12	          D	D
CAR3	           18-May-12	          C	C
CAR1	           08-Feb-12	          C	A
CAR1	           18-May-12	          C	B
CAR5	           24-May-12	          D	C
CAR3	           11-May-12	          C	B
CAR5	           22-Aug-12	          B	B
CAR5	           17-Sep-12	          A	B

desired results:

car-index	installed_date	firebar-grade	frame-grade
CAR1	            24-May-12	       D	D
CAR3	            18-May-12	       C	C
CAR5	            17-Sep-12	       A	B

I've tried this, but the results are incorrect.

SQL

select car_index, frame_grade, firebar_grade, max(installed_date) as recentdate from car 
group by car_index, frame_grade, firebar_grade;

Posted 8-Feb-12 3:37am

nikki88

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2 solutions

Solution 1

Try this

SQL

SELECT C.car_index,MAX(C.firebar_grade),MAX(C.frame_grade) FROM Car C 
Group by C.car_index

Hope this helps if yes then accept and vote the answer otherwise revert back with your queries
--Rahul D.

Posted 8-Feb-12 3:50am

RDBurmon

Comments

Christian Graus 8-Feb-12 10:03am

I don't think that has any chance of working. It will grab the MAX value, not the one associated with the date.

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Christian Graus · Accepted Answer · 2012-02-08T04:19:00

Solution 2

SQL

select * from car c where c.installed_date = (select MAX(installed_date) from car cr where cr.[car-index] = c.[car-index])

Posted 8-Feb-12 4:19am

Christian Graus

Comments

nikki88 9-Feb-12 1:45am

Thank you very much Christain! it works perfectly :)