Make sure we only create the minimum number of table indexes for MySQL.

This patch simplifies a bunch of code for all backends and removes some
duplicate index creation for MySQL, in particular (versions 4.x and later).
Patch from Nis Jørgensen.

Fixed #5671, #5680, #7170, #7186.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@7790 bcc190cf-cafb-0310-a4f2-bffc1f526a37

5 files changed, 5 insertions, 6 deletions

diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
index 7a4e46a7d7..36a2339638 100644
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -41,8 +41,6 @@ class BaseDatabaseWrapper(local):
 
 class BaseDatabaseFeatures(object):
     allows_group_by_ordinal = True
-    allows_unique_and_pk = True
-    autoindexes_primary_keys = True
     inline_fk_references = True
     needs_datetime_string_cast = True
     supports_constraints = True
diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index 23735a023b..cfa6b0e56c 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -60,7 +60,6 @@ server_version_re = re.compile(r'(\d{1,2})\.(\d{1,2})\.(\d{1,2})')
 # TRADITIONAL will automatically cause most warnings to be treated as errors.
 
 class DatabaseFeatures(BaseDatabaseFeatures):
-    autoindexes_primary_keys = False
     inline_fk_references = False
     empty_fetchmany_value = ()
     update_can_self_select = False
diff --git a/django/db/backends/mysql_old/base.py b/django/db/backends/mysql_old/base.py
index e57aee6a04..adfa03d569 100644
--- a/django/db/backends/mysql_old/base.py
+++ b/django/db/backends/mysql_old/base.py
@@ -64,7 +64,6 @@ class MysqlDebugWrapper:
             return getattr(self.cursor, attr)
 
 class DatabaseFeatures(BaseDatabaseFeatures):
-    autoindexes_primary_keys = False
     inline_fk_references = False
     empty_fetchmany_value = ()
     update_can_self_select = False
diff --git a/django/db/backends/oracle/base.py b/django/db/backends/oracle/base.py
index 1df6bac069..54517662c1 100644
--- a/django/db/backends/oracle/base.py
+++ b/django/db/backends/oracle/base.py
@@ -24,7 +24,6 @@ IntegrityError = Database.IntegrityError
 
 class DatabaseFeatures(BaseDatabaseFeatures):
     allows_group_by_ordinal = False
-    allows_unique_and_pk = False        # Suppress UNIQUE/PK for Oracle (ORA-02259)
     empty_fetchmany_value = ()
     needs_datetime_string_cast = False
     supports_tablespaces = True
diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index a893c25e63..dc5cb9609c 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -91,7 +91,7 @@ class Field(object):
         self.name = name
         self.verbose_name = verbose_name
         self.primary_key = primary_key
-        self.max_length, self.unique = max_length, unique
+        self.max_length, self._unique = max_length, unique
         self.blank, self.null = blank, null
         # Oracle treats the empty string ('') as null, so coerce the null
         # option whenever '' is a possible value.
@@ -168,6 +168,10 @@ class Field(object):
         except KeyError:
             return None
 
+    def unique(self):
+        return self._unique or self.primary_key
+    unique = property(unique)
+
     def validate_full(self, field_data, all_data):
         """
         Returns a list of errors for this field. This is the main interface,