MySQL - Fetching lowest value

Question

My database structure contains columns: id, name, value, dealer. I want to retrieve row with lowest value for each dealer

Answer 1

These answers seem to miss the edge case of having multiple minimum values for a dealer and only wanting to return one row.

If you want to only want one value for each dealer you can use row_number partition - group - the table by dealer then order the data by value and id. we have to make the assumption that you will want the row with the smallest id.

SELECT ord_tbl.id, 
       ord_tbl.name, 
       ord_tbl.value, 
       ord_tbl.dealer
FROM (SELECT your_table.*, 
      ROW_NUMBER() over (PARTITION BY dealer ORDER BY value ASC, ID ASC) 
      FROM your_table 
     ) AS ord_tbl
WHERE ord_tbl.ROW_NUMBER = 1;

Be careful though that value, id and dealer are indexed. If not this will do a full table scan and can get pretty slow...

Answer 2

select id,name,MIN(value) as pkvalue,dealer from TABLENAME 
group by id,name,dealer;

here you group all rows by id,name,dealer and then you will get min value as pkvalue.

Answer 3

First you need to resolve the lowest value for each dealer, and then retrieve rows having that value for a particular dealer. I would do this that way:

SELECT a.*
FROM   your_table AS a
       JOIN (SELECT dealer,
                    Min(value) AS m
             FROM   your_table
             GROUP  BY dealer) AS b
         ON ( a.dealer= b.dealer
              AND a.value = b.m ) 

Answer 4

Try following:

SELECT dealer, MIN(value) as "Lowest value"
FROM value
GROUP BY dealer;

Answer 5

Solution1:

SELECT t1.* FROM your_table t1
JOIN (
  SELECT MIN(value) AS min_value, dealer
  FROM your_table 
  GROUP BY dealer
) AS t2 ON t1.dealer = t2.dealer AND t1.value = t2.min_value

Solution2:

SELECT t1.* FROM your_table t1
LEFT JOIN your_table t2
ON t1.dealer = t2.dealer AND t1.value > t2.value
WHERE t2.value IS NULL

This problem is very famous, so there is a special page for this in Mysql's manual.

Check this: Rows Holding the Group-wise Maximum/Minimum of a Certain Column

Answer 6

select id, name, value, dealer from yourtable where dealer 
in(select min(dealer) from yourtable group by name, value)