Include another select column based on data - MySQL - mysql

Question

How do I include SUM((pm.Quantity * bl.TotalQty)) AS NextBOMItemCount WHERE projectbomlist.ParentPartNum = bl.PartNum?
The data should not be changed, the same data should be retrieved, the however additional column has to be included.
VIEW: `NEWprojectBOMItemCount
select
`pm`.`ProjectCode` AS `ProjectCode`,
`bl`.`PartNum` AS `PartNum`,
sum((`pm`.`Quantity` * `bl`.`TotalQty`)) AS `BOMItemCount`,
`bl`.`mp` AS `mp`,
`p`.`complete` AS `complete`,
`bl`.`RMInd` AS `RMInd`,
`bl`.`M_PartNum` AS `M_PartNum`
from
(
(`projectmachine` `pm` join `projectbomlist` `bl`)
join `projects` `p`
)
where
(
(`pm`.`MachineListID` = `bl`.`MachineListID`)
and (`pm`.`ProjectCode` = `bl`.`ProjectCode`)
and (`pm`.`ProjectCode` = `p`.`ProjectCode`)
and (`p`.`AfterProjectHeirarchyInd` = 'Y')
)
and and pm.ProjectCode = 'AB212323'
group by
`pm`.`ProjectCode` ,
`bl`.`PartNum`
order by
`pm`.`ProjectCode` ,
`bl`.`PartNum`
Or, another option can be, please consider above view used in below query, please suggest changes to the below query as shown above (repeating here)
`sum((pm.Quantity * bl.TotalQty)) AS NextBOMItemCount where projectbomlist.ParentPartNum = bl.PartNum` - in place of `(select-NextBOMItemCount)`?
Please see PBLH.ParentPartNum is the column that I should compare with BL.ProjectCode to get NextBOMItemCount value.
QUERY calling view: NEWprojectBOMItemCount
Select
BL.PartNum PartNumber,
PBLH.ParentPartNum NextBOM,
(select-NextBOMItemCount),
BOMItemCount TotalQty,
PL.Description,
BL.MP as PartType,
PL.Vendor,
PL.QBType
from
NEWprojectBOMItemcount BL,
bomwiz.partslist PL,
bomwiz.projectbomlistheirarchy PBLH
Where
BL.PartNum = PL.PartNum
And BL.PartNum = PBLH.PartNum
And BL.ProjectCode = PBLH.ProjectCode
And BL.projectCode = 'AB212323'
Order By PartNumber

Answer 1

I think that you are looking for conditional aggregation. Your requirement could be expressed as follows:
SUM(
CASE WHEN blh.ParentPartNum = bl.PartNum
THEN pm.Quantity * bl.TotalQty
ELSE 0
END
) AS NextBOMItemCount
Let me pinpoint other issues with your query:
you have unwanted parentheses all around, and I am suspicious about the syntax of the JOINs ; you need to move conditions to the ON clause of the relevant JOIN.
every non-aggregated column must appear in the GROUP BY clause - you have missing columns there
backquotes are usually not needed
Here is an updated version of the query:
SELECT
pm.ProjectCode AS ProjectCode,
bl.PartNum AS PartNum,
SUM(pm.Quantity * bl.TotalQty) AS BOMItemCount,
SUM(
CASE WHEN blh.ParentPartNum = bl.PartNum
THEN pm.Quantity * bl.TotalQty
ELSE 0
END
) AS NextBOMItemCount,
bl.mp AS mp,
p.complete AS complete,
bl.RMInd AS RMInd,
bl.M_PartNum AS M_PartNum
FROM
projectmachine AS pm
INNER JOIN projectbomlist AS bl
ON pm.MachineListID = bl.MachineListID
AND pm.ProjectCode = bl.ProjectCode
INNER JOIN join projects AS p
ON pm.ProjectCode = p.ProjectCode
AND p.AfterProjectHeirarchyInd = 'Y'
INNER JOIN projectbomlistheirarchy blh
ON bl.ProjectCode = blh.ProjectCode
WHERE
pm.ProjectCode = 'AB212323'
GROUP BY
pm.ProjectCode,
bl.PartNum,
bl.mp,
p.complete,
bl.RMInd,
bl.M_PartNum
ORDER BY
pm.ProjectCode,
bl.PartNum