id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
34144	Casting a string inside a JSONField into an integer does not work on PostgreSQL	Clément Escolano	nobody	"Hello

When casting an integer represented as a string inside a JSONField on PostgreSQL, there is the following error:

{{{
django.db.utils.DataError: cannot cast jsonb string to type integer
}}}

It works with a SQLite database.

To reproduce the error, you can create a simple model with a JSONField:

{{{
class MyModel(models.Model):
    data = models.JSONField()

MyModel.objects.create(data={""value"": ""3""})

MyModel.objects.annotate(actual_value=Cast(""data__value"", output_field=IntegerField())).first()
}}}

The produced query is the following:

{{{
SELECT ""myapp_mymodel"".""id"",
       ""myapp_mymodel"".""data"",
       ((""myapp_mymodel"".""data"" -> 'value'))::integer AS ""actual_value""
FROM ""myapp_mymodel""
LIMIT 1;
}}}

This [https://stackoverflow.com/a/25810945 stackoverflow question] hints that adding an extra "">"" after ""->"" fixes it and indeed the following query returns the correct result:

{{{
SELECT ""myapp_mymodel"".""id"",
       ""myapp_mymodel"".""data"",
       ((""myapp_mymodel"".""data"" ->> 'value'))::integer AS ""actual_value""
FROM ""myapp_mymodel""
LIMIT 1;
}}}"	Bug	closed	Database layer (models, ORM)	4.1	Normal	invalid	postgresql, jsonfield, cast		Unreviewed	0	0	0	0	0	0