Question

选择最小值时遇到问题。我已经创建了内部联接与2表和SQL查询中的简单计算。现在我想从计算中选择最小值。在这里我的查询..

 $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";

我想找到“总数”的最小值..

Answer 1

更新：以下解决方案特定于MySQL。

<小时/> 您可以获得的最接近您自己的代码的答案是在查询结束时使用

$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
";

。

MIN()

也可以使用聚合函数group by和$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 ";：

GROUP BY

请注意，在这种情况下，除了具有聚合函数的列之外的所有列都在pageA[\adminlogin]子句中。

在INNER JOIN上选择MIN值

1 个答案: