1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
Extending a Schema
------------------
.. currentmodule:: graphql.utilities
With GraphQL-core 3 you can also extend a given schema using type extensions. For
example, we might want to add a ``lastName`` property to our ``Human`` data type to
retrieve only the last name of the person.
This can be achieved with the :func:`extend_schema` function as follows::
from graphql import extend_schema, parse
schema = extend_schema(schema, parse("""
extend type Human {
lastName: String
}
"""))
Note that this function expects the extensions as an AST, which we can get using the
:func:`~graphql.language.parse` function. Also note that the :func:`extend_schema`
function does not alter the original schema, but returns a new schema object.
We also need to attach a resolver function to the new field::
def get_last_name(human, info):
return human['name'].rsplit(None, 1)[-1]
schema.get_type('Human').fields['lastName'].resolve = get_last_name
Now we can query only the last name of a human::
from graphql import graphql_sync
result = graphql_sync(schema, """
{
human(id: "1000") {
lastName
homePlanet
}
}
""")
print(result)
This query will give the following result::
ExecutionResult(
data={'human': {'lastName': 'Skywalker', 'homePlanet': 'Tatooine'}},
errors=None)
|
