#33789: Table and colums with more then 30 chars can no longer be found on 
Oracle.
-------------------------------------+-------------------------------------
     Reporter:  Paul in 't Hout      |                    Owner:  nobody
         Type:  Bug                  |                   Status:  closed
    Component:  Database layer       |                  Version:  4.0
  (models, ORM)                      |
     Severity:  Normal               |               Resolution:  needsinfo
     Keywords:  oracle               |             Triage Stage:
                                     |  Unreviewed
    Has patch:  0                    |      Needs documentation:  0
  Needs tests:  0                    |  Patch needs improvement:  0
Easy pickings:  0                    |                    UI/UX:  0
-------------------------------------+-------------------------------------

Comment (by Paul in 't Hout):

 Here are 2 fictitious models that would have this problem.
 In our case they would have been created with a django 1.x , but for this
 bug I would think 3.2 would also reproduce.

 1. Create migration in 3.2.13
 2. Migrate
 3. Upgrade to 4.0.5
 4. Query the models

 {{{
 class LongColumnName( models.Model):
     id = models.AutoField(primary_key=True)
     name = models.CharField(max_length=100, db_index=True, unique=True)
     my_very_long_boolean_field_setting =
 models.BooleanField(default=False)

     class Meta:
         db_table = "long_column_name"
         app_label = "my_app"
         ordering = ["id", "name"]
 }}}

 And for a long table name

 {{{
 class LongTableName( models.Model):
     id = models.AutoField(primary_key=True)
     name = models.CharField(max_length=100, db_index=True, unique=True)
     short_field = models.BooleanField(default=False)

     class Meta:
         db_table = "my_very_long_table_name_for_demo"
         app_label = "my_app"
         ordering = ["id", "name"]
 }}}

 I have now gone ahead with a workaround. Which, for the above tables,
 would look like this:

 1. Get the table and column name as defined in the database for the long
 fields and table names:
 MY_VERY_LONG_BOOLEAN_FIELD76a5
 MY_VERY_LONG_TABLE_NAME_FOd906

 2.  Update the models with the table_name and db_column name attributes:

 {{{
 class LongColumnName( models.Model):
     id = models.AutoField(primary_key=True)
     name = models.CharField(max_length=100, db_index=True, unique=True)
     my_very_long_boolean_field_setting =
 models.BooleanField(default=False,
 db_column="MY_VERY_LONG_BOOLEAN_FIELD76a5"
 )

     class Meta:
         db_table = "long_column_name"
         app_label = "my_app"
         ordering = ["id", "name"]

 class LongTableName( models.Model):
     id = models.AutoField(primary_key=True)
     name = models.CharField(max_length=100, db_index=True, unique=True)
     short_field = models.BooleanField(default=False)

     class Meta:
         db_table = "MY_VERY_LONG_TABLE_NAME_FOd906"
         app_label = "my_app"
         ordering = ["id", "name"]
 }}}

 3. Create a migration
 4. Update to Django 4.0.5
 5. Fake the migration.
   I needed to auto-fake , so I added an empty apply / unapply method as
 described here (https://stackoverflow.com/questions/49150541/auto-fake-
 django-migration)

-- 
Ticket URL: <https://code.djangoproject.com/ticket/33789#comment:6>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/010701818004a62e-b4da39c1-52c0-4eaf-9c73-14dd5718b143-000000%40eu-central-1.amazonses.com.

Reply via email to