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
34060	Creating CheckConstraint on JSONField with __exact lookup on key transforms crashes on Oracle.	Mariusz Felisiak	raydeal	"Creating `CheckConstraint` on `JSONField` with `__exact` lookup on key transforms crashes on Oracle:
{{{
class Version(models.Model):
    metadata = models.JSONField(null=True)

    class Meta:
        constraints = [
            models.CheckConstraint(
                check=models.Q(metadata__stage=""stable""),
                name=""only_stable_version"",
            ),
        ]
}}}

Crashes with:
{{{
  File ""/django/django/db/backends/oracle/base.py"", line 557, in execute
    return self.cursor.execute(query, self._param_generator(params))
cx_Oracle.DatabaseError: ORA-00904: ""DBMS_LOB"".""SUBSTR"": invalid identifier
}}}

`DBMS_LOB.SUBSTR` is unnecessary in this case.


It's not a regression."	Bug	closed	Database layer (models, ORM)	4.0	Normal	fixed	Oracle	David Sanders	Ready for checkin	1	0	0	0	0	0