How to make peewee ORM return custom fields conversions from CTE?

I'm trying to use the recursive CTE from Peewee ORM that returns the same field types as a non-recursive query.

According to the Peewee docs, you use the select_from method, with columns from the previous query, like this:

query = (cte
         .select_from(cte.c.name, cte.c.level, cte.c.path)
         .order_by(cte.c.path))

My query basically works. However, my table uses a couple of custom field types. When using regular query those fields are converted by the field to objects as defined in the python_value method. But when using the CTE query those values come as the raw database type, not converted by the custom field method.

Is there a way to tell the query to use the field conversion?

I tried .select_from(cte.c.myfield.convert(MyEnum), ...), but that doesn't work.

Solution

The select_from() method returns you a "bare" Select query that does not know so much about converting values. This should work:

from peewee import ModelSelect

class Reg(Model):
    value = TextField()

Reg.create(value='1')
Reg.create(value='22')

cte = Reg.select(Reg.value).cte('regs', columns=('val',))
query = ModelSelect(Reg, (cte.c.val.converter(int),))
query = query.from_(cte).with_cte(cte)
for row in query:
    print(type(row.val), row.val)

# <class 'int'> 1
# <class 'int'> 22