Select MIN value on INNER JOIN

Question

I have some problem when selecting Minimum value. i have create inner join with 2 table and simple calculation in SQL query. Now i want to select minimum value from the calculation. here my query..

 $sql = "SELECT jobmatl_mst.item as item2,jobmatl_mst.u_m, job_mst.item, jobmatl_mst.job, jobmatl_mst.item as item2, jobmatl_mst.description, jobmatl_mst.matl_qty_conv , itemwhse_mst.item  as whseitem,itemwhse_mst.qty_on_hand, itemwhse_mst.qty_on_hand / jobmatl_mst.matl_qty_conv as total 
FROM job_mst 
INNER JOIN jobmatl_mst ON job_mst.job=jobmatl_mst.job 
INNER JOIN itemwhse_mst ON jobmatl_mst.item=itemwhse_mst.item 
WHERE job_mst.item ='601010944003' AND job_mst.type='S'
ORDER BY total";

i want to find minimum value for "total"..

Answer 1

Update: The following solution is specific to MySQL.

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The simplest answer that you can get that is close to your own code is to use ORDER BY total LIMIT 1 at the end of your query.

 $sql = " SELECT jobmatl_mst.item as item2, jobmatl_mst.u_m, job_mst.item, jobmatl_mst.job, jobmatl_mst.item as item2, jobmatl_mst.description, jobmatl_mst.matl_qty_conv , itemwhse_mst.item as whseitem, itemwhse_mst.qty_on_hand, itemwhse_mst.qty_on_hand / jobmatl_mst.matl_qty_conv as total FROM job_mst INNER JOIN jobmatl_mst ON job_mst.job=jobmatl_mst.job INNER JOIN itemwhse_mst ON jobmatl_mst.item=itemwhse_mst.item WHERE job_mst.item ='601010944003' AND job_mst.type='S' ORDER BY total # Sort the result in a # way that lowest is first and highest is last LIMIT 1 # Then we need the first value "; 

Usage of aggregate function MIN() and group by is also possible:

 $sql = " SELECT jobmatl_mst.item as item2, jobmatl_mst.u_m, job_mst.item, jobmatl_mst.job, jobmatl_mst.item as item2, jobmatl_mst.description, jobmatl_mst.matl_qty_conv , itemwhse_mst.item as whseitem, itemwhse_mst.qty_on_hand, MIN(itemwhse_mst.qty_on_hand / jobmatl_mst.matl_qty_conv) as min_total FROM job_mst INNER JOIN jobmatl_mst ON job_mst.job=jobmatl_mst.job INNER JOIN itemwhse_mst ON jobmatl_mst.item=itemwhse_mst.item WHERE job_mst.item ='601010944003' AND job_mst.type='S' GROUP BY jobmatl_mst.item as item2, jobmatl_mst.u_m, job_mst.item, jobmatl_mst.job, jobmatl_mst.item as item2, jobmatl_mst.description, jobmatl_mst.matl_qty_conv , itemwhse_mst.item as whseitem, itemwhse_mst.qty_on_hand "; 

Note that in this case all the columns other than the one with aggregate function comes in the GROUP BY clause.