Convert between Python and Postgres types

By default Quart-DB uses the default converters whilst ensuring that JSON is converted, using the stdlib json.loads and json.dumps functions if required. Custom type converters are supported, but depend on the DB backend used.

Postgres - asyncpg

To define a custom type converter (also called codecs) can be specified the set_converter method can be used. For example for enums:

from enum import Enum

class Options(Enum):
    A = "A"
    B = "B"

db.set_converter("options_t", lambda type_: type_.value, Options)

The keyword argument schema can be used to specify the schema to which the typename belongs.

SQLite - aiosqlite

To define a custom type converter (also called codecs) can be specified the set_converter method can be used. For example for enums:

from enum import Enum

class Options(Enum):
    A = "A"
    B = "B"

db.set_converter(
    "options_t", lambda type_: type_.value, Options, pytype=Options
)

Note the pytype argument is required and the keyword argument schema has no affect.