[web2py] Postgresql (DAL) error, help needed

[lyn2py]

Hi, 

I am using Postgresql and encountered the following errors. These errors do 
not come up when I use SQLite.

I have the following code:

###MODEL
db.define_table('deals', 
    Field('deal_name', 'string',length=255,requires=IS_NOT_EMPTY()),
    Field('num_A', 'integer',default=0),
    Field('num_B','integer',default=0),
    Field('num_C', 'integer',default=0),
    Field('month', requires=IS_IN_SET([1,2,3])),
    Field('approved', 'boolean',label="Approved?"),
    Field('created_by', 'reference 
auth_user',default=auth.user_id,writable=False,readable=False),
)



###CONTROLLER FIRST ATTEMPT
rows = db(db.deals.approved==1).select(db.deals.month, 
        db.deals.num_A.sum(), db.deals.num_B.sum(),
        db.deals.num_C.sum(), db.auth_user.ALL,
        left=db.auth_user.on(db.auth_user.id==db.deals.created_by),
        orderby=db.deals.A|db.deals.B,
        groupby=db.deals.created_by|db.deals.month
    )

ERROR: ProgrammingError: ('ERROR', '42803', 'column "auth_user.id" must 
appear in the GROUP BY clause or be used in an aggregate function')

*So I added some code which I thought was irrelevant, but a NEW error sets 
in:*

###CONTROLLER SECOND ATTEMPT
rows = db(db.deals.approved==1).select(db.deals.month, 
        db.deals.num_A.sum(), db.deals.num_B.sum(),
        db.deals.num_C.sum(), db.auth_user.ALL,
        left=db.auth_user.on(db.auth_user.id==db.deals.created_by),
        orderby=db.deals.A|db.deals.B,
        groupby=db.deals.created_by|db.deals.month|db.auth_user.id
    )

ERROR: ProgrammingError: ('ERROR', '42803', 'column "deals.num_C" must 
appear in the GROUP BY clause or be used in an aggregate function')

Now I am at a loss, should I keep adding unnecessary fields to groupby?

I appreciate help. Thank you!

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