Using sqlalchemy, how transform 1 & 0 to boolean in postgres? - postgresql

Question

I'm getting some data in JSON, where boolean values are 0 & 1.
In the postgres table is a boolean field, and expect true & false.
I try this when loading the table:
class PGBool(types.TypeDecorator):
impl = types.BOOLEAN
def process_result_value(self, value, dialect):
#print value
if value is not None:
return bool(value)
return value
def listen(self, table, column_info):
type_ = column_info['type']
print column_info['name'], type_
if str(type_).split('.')[-1] == 'BOOLEAN':
column_info['type'] = PGBool
return column_info
def getTable(self, name):
return sq.Table(
name,
self.meta,
autoload=True,
autoload_with=self.con,
listeners=[
('column_reflect', listen)
]
)
def saveRecord(self, table, data):
..
..
if exist:
self.con.execute(
table.update().where(table.c.id == theGuid),
data
)
else:
self.con.execute(
table.insert(),
data
)
But the data is not converted, and still try to insert 0 & 1.

Answer 1

when you use TypeDecorator, there's two sides to the data to be concerned with. One is the data going into the database, and the other is the data coming out. The side going in is referred to as the "bind parameters" and the side going out is the "result" data. Since you want here to deal with an INSERT, you're on the bind side, so the TypeDecorator would look like:
from sqlalchemy.types import TypeDecorator, Boolean
class CoerceToBool(TypeDecorator):
impl = Boolean
def process_bind_param(self, value, dialect):
if value is not None:
value = bool(value)
return value