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
33789	Document changes in quoting table/colums names on Oracle.	Paul in 't Hout	Mariusz Felisiak	"While in the proces of updating our project from Django 2.2 to 3.2 to 4.0 I noticed that things started to break down in 4.0.

Since upgrading to 4.0, tables with names longer than 30 chars fail with
ORA-00942: table or view does not exist
models with columns with names longer than 30 chars fail with
ORA-00904: ""COMPONENT_ATTRIBUTE_METADATA"".""REQUIRES_ILOM_CONNECT_FOR_DD63"": invalid identifier



When I run the following on django 2.2 / 3.2.13 with python 3.6

{{{
from django.db.backends.utils import truncate_name
truncate_name(""very_long_database_table_or_column"" length=30)
Out[7]: 'VERY_LONG_DATABASE_TABLE_O20cb'
}}}

Then run the same on django 4.0.5 with python 3.9
{{{
from django.db.backends.utils import truncate_name
truncate_name(""very_long_database_table_or_column"", length=30)
Out[6]: 'very_long_database_table_o0c9a'
}}}

The hash value is different.  As a result a table or column name is queried that does not exist, because they where created using the older algorithm.

I believe this was broken by this change: https://code.djangoproject.com/ticket/32653

"	Bug	closed	Database layer (models, ORM)	4.0	Release blocker	fixed	oracle		Ready for checkin	1	0	0	0	0	0