Commit 6de37264 authored by Shai Berger's avatar Shai Berger
Browse files

Fixed #13245: Explained Oracle's behavior w.r.t db_table 

and how to prevent table-name truncation

Thanks russellm & timo for discussion, and timo for review.

Backported from master 317040a7
parent ead7c496

docs/ref/databases.txt

+16 −0
Original line number Diff line number Diff line
@@ -705,6 +705,22 @@ Naming issues 
Oracle imposes a name length limit of 30 characters. To accommodate this, the

backend truncates database identifiers to fit, replacing the final four

characters of the truncated name with a repeatable MD5 hash value.

Additionally, the backend turns database identifiers to all-uppercase.



To prevent these transformations (this is usually required only when dealing

with legacy databases or accessing tables which belong to other users), use

a quoted name as the value for ``db_table``::



    class LegacyModel(models.Model):

        class Meta:

       	    db_table = '"name_left_in_lowercase"'



    class ForeignModel(models.Model):

        class Meta:

       	    db_table = '"OTHER_USER"."NAME_ONLY_SEEMS_OVER_30"'



Quoted names can also be used with Django's other supported database 

backends; except for Oracle, however, the quotes have no effect.



When running syncdb, an ``ORA-06552`` error may be encountered if

certain Oracle keywords are used as the name of a model field or the

docs/ref/models/options.txt

+12 −0
Original line number Diff line number Diff line
@@ -67,6 +67,18 @@ Django quotes column and table names behind the scenes. 
    the table name via ``db_table``, particularly if you are using the MySQL

    backend. See the :ref:`MySQL notes <mysql-notes>` for more details.



.. admonition:: Table name quoting for Oracle



   In order to to meet the 30-char limitation Oracle has on table names,

   and match the usual conventions for Oracle databases, Django may shorten

   table names and turn them all-uppercase. To prevent such transformations,

   use a quoted name as the value for ``db_table``::



       db_table = '"name_left_in_lowercase"'



   Such quoted names can also be used with Django's other supported database 

   backends; except for Oracle, however, the quotes have no effect. See the

   :ref:`Oracle notes <oracle-notes>` for more details.



``db_tablespace``

-----------------