Question

i have a table like this

id name date   group_id  
 1  n1   1     1
 2  n2   1     1
 3  n4   2     2
 4  n5   2     2 

i want ton write a query to return the group_id without duplicate ordered by date ASC

$query = " SELECT DISTINCT group_id FROM table ORDER BY date ASC";

this query will return 2 , 1 but this query is just going to consider date of the first row of each group_id to order the results

like if i have table like this

id name price  date   group_id  
 1  n1   2300    1     1
 2  n2   3000    3     1
 3  n4   4000    2     2
 4  n5   2000    2     2 

second row with with ‘1’ as group_id has the biggest date so i should get 1,2 as result but query doesn’t care about second row with the ‘1’ group_id and still return 2,1
it only cares about the first row of each id for ordering the results

hopefully there is a easy way to solve this and i dont need to do something wird like putting everything in the 2d array and order that then deleting duplicates

Answer 1

Try this

select group_id,max(date) as SortDate
from table
group by group_id
order by SortDate