Michael thanks for the help, this is how I was able to get it working.
Probably isn't the most efficient, but it works, I couldn't implement it
the way you proposed because I still need to be able to do a_row = b_row.A
-
sql_b = select([b_table, sql_a.c.name], b_table.c.a_id =
sql_a.c.id).alias('b_query')
mapper(b, sql_b, properties = {
'A' : relation(A, lazy=False, primaryjoin=(sql_a.c.id==sql_b.c.a_id))})
mapper(C, c_table, properties = {
'Bs' : relation(B, backref='C', cascade='all, delete-orphan',
order_by=[sql_b.c.name, sql_c.c.value1,
sql_c.c.value2]),
})
Michael Bayer wrote:
On Dec 5, 2007, at 1:56 PM, David Gardner wrote:
I have three tables a(a query of a really), b, c
a has a 1-many relationship with b
c has a 1-many relationship with b
What I would like to do is in my mapper for table c, is sort the order
of rows from b by a.name.
I don't know how to do this or if it is possible. What I have looks
like:
sql_a = select([table_a], table_a.c.col1='some
value').alias('a_query')
mapper(B, b_table, properties = {
'A' : relation(sql_a, lazy=False,
primaryjoin=(sql_a.c.id==table_b.c.a_id))})
mapper(C, c_table, properties = {
'Bs' : relation(B, backref='C', cascade='all, delete-orphan',
order_by=[C.A.name, c_table.c.value1,
c_table.c.value2]),
})
This gets me an AttributeError: 'InstrumentedAttribute' object has no
attribute 'name'
this error is becuase C.A is not a gateway to the columns on the A
mapper.
I have also tried:
order_by=[A.name
and
order_by=[sql_a.c.name
both get me this: ProgrammingError: (ProgrammingError) missing
FROM-clause entry for table sql_a.name
this error is because the relation from C-B has no relationship to
As table at all, and it is not used in the generated query. to have
As table be a part of it in all cases, youd have to map A's column
onto B's mapper, which is fairly messy:
mapper(B, select([b_table, a.c.name], b_table.c.a_id==a.c.id))
you can try creating this mapper as a non-primary mapper and using
it for just the C-B relation:
s = select([b_table, a.c.name], b_table.c.a_id==a.c.id)
mapper(C, ctable, properties={
'bs':relation(mapper(B, s, non_primary=True), order_by=[s.c.name])
})
I havent tried the above myself so see if it works for you.
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
sqlalchemy group.
To post to this group, send email to sqlalchemy@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/sqlalchemy?hl=en
-~--~~~~--~~--~--~---
