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	Table and colums with more then 30 chars can no longer be found / queried after migrating from django 3.2 to 4.0 using an Oracle backend	Paul in 't Hout	nobody	"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	new	Database layer (models, ORM)	4.0	Normal		oracle		Unreviewed	0	0	0	0	0	0