Group by error of a query in db2 SQL

Question

The Consultation:

Select ITEMNFS.Recnum, ITEMNFS.ITEM, sum(ITEMNFS.VL_TOTAL), sum(ITEMNFS.QTDE_FATUR), ITEM.PER_IPI 
from ITEMNFS 
inner join ITEM on ITEMNFS.ITEM = ITEM.ITEM inner join NFS on ((ITEMNFS.NRO_NFS = NFS.NRO_NFS) and (ITEMNFS.SERIE = NFS.SERIE)) 
where (NFS.DT_EMISSAO between '2017-12-01' and '2018-02-20') 
group by ITEMNFS.ITEM

The error is as follows:

SQL0119N An expression started with "PER_IPI" specified in a SELECT or HAVING clause not specified in GROUP BY clause or is in a SELECT, HAVING or ORDER BY clause with a function of column without a specified GROUP BY clause. SQLSTATE=42803

Answer 1

Error says you need to add all clauses that are not sum() at the group by. Try it this way:

Select ITEMNFS.Recnum, ITEMNFS.ITEM, sum(ITEMNFS.VL_TOTAL), sum(ITEMNFS.QTDE_FATUR), ITEM.PER_IPI 
from ITEMNFS 
inner join ITEM on ITEMNFS.ITEM = ITEM.ITEM inner join NFS on ((ITEMNFS.NRO_NFS = NFS.NRO_NFS) and (ITEMNFS.SERIE = NFS.SERIE)) 
where (NFS.DT_EMISSAO between '2017-12-01' and '2018-02-20') 
group by ITEMNFS.Recnum, ITEMNFS.ITEM, ITEM.PER_IPI 

You can have a read at that link about the group by, there are several examples of selects with many columns.