Refactored get_sql_sequence_reset() to DatabaseOperations.sequence_reset_sql(). Refs #5106

git-svn-id: http://code.djangoproject.com/svn/django/trunk@5964 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/management/commands/loaddata.py

@@ -15,7 +15,7 @@ class Command(BaseCommand):
     def handle(self, *fixture_labels, **options):
         from django.db.models import get_apps
         from django.core import serializers
-        from django.db import connection, transaction, backend
+        from django.db import connection, transaction
         from django.conf import settings
 
         self.style = no_style()
@@ -105,7 +105,7 @@ class Command(BaseCommand):
                                 (format, fixture_name, humanize(fixture_dir))
 
         if count[0] > 0:
-            sequence_sql = backend.get_sql_sequence_reset(self.style, models)
+            sequence_sql = connection.ops.sequence_reset_sql(self.style, models)
             if sequence_sql:
                 if verbosity > 1:
                     print "Resetting sequences"

django/core/management/commands/sqlsequencereset.py

@@ -5,5 +5,5 @@ class Command(AppCommand):
     output_transaction = True
 
     def handle_app(self, app, **options):
-        from django.db import backend, models
+        from django.db import connection, models
-        return '\n'.join(backend.get_sql_sequence_reset(self.style, models.get_models(app)))
+        return '\n'.join(connection.ops.sequence_reset_sql(self.style, models.get_models(app)))

django/db/backends/__init__.py

@@ -150,3 +150,13 @@ class BaseDatabaseOperations(object):
         color_style() or no_style() in django.core.management.color.
         """
         raise NotImplementedError()
+
+    def sequence_reset_sql(self, style, model_list):
+        """
+        Returns a list of the SQL statements required to reset sequences for
+        the given models.
+
+        The `style` argument is a Style object as returned by either
+        color_style() or no_style() in django.core.management.color.
+        """
+        return [] # No sequence reset required by default.

django/db/backends/ado_mssql/base.py

@@ -109,11 +109,6 @@ def get_start_transaction_sql():
 def get_tablespace_sql(tablespace, inline=False):
     return "ON %s" % quote_name(tablespace)
 
-def get_sql_sequence_reset(style, model_list):
-    "Returns a list of the SQL statements to reset sequences for the given models."
-    # No sequence reset required
-    return []
-
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',

django/db/backends/dummy/base.py

@@ -44,6 +44,5 @@ dictfetchone = complain
 dictfetchmany = complain
 dictfetchall = complain
 get_start_transaction_sql = complain
-get_sql_sequence_reset = complain
 
 OPERATOR_MAPPING = {}

django/db/backends/mysql/base.py

@@ -191,11 +191,6 @@ dictfetchall  = util.dictfetchall
 def get_start_transaction_sql():
     return "BEGIN;"
 
-def get_sql_sequence_reset(style, model_list):
-    "Returns a list of the SQL statements to reset sequences for the given models."
-    # No sequence reset required
-    return []
-
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',

django/db/backends/mysql_old/base.py

@@ -210,11 +210,6 @@ dictfetchall  = util.dictfetchall
 def get_start_transaction_sql():
     return "BEGIN;"
 
-def get_sql_sequence_reset(style, model_list):
-    "Returns a list of the SQL statements to reset sequences for the given models."
-    # No sequence reset required
-    return []
-
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'LIKE %s',

django/db/backends/oracle/base.py

@@ -95,6 +95,23 @@ class DatabaseOperations(BaseDatabaseOperations):
         else:
             return []
 
+    def sequence_reset_sql(self, style, model_list):
+        from django.db import models
+        output = []
+        query = _get_sequence_reset_sql()
+        for model in model_list:
+            for f in model._meta.fields:
+                if isinstance(f, models.AutoField):
+                    sequence_name = get_sequence_name(model._meta.db_table)
+                    output.append(query % {'sequence':sequence_name,
+                                           'table':model._meta.db_table})
+                    break # Only one AutoField is allowed per model, so don't bother continuing.
+            for f in model._meta.many_to_many:
+                sequence_name = get_sequence_name(f.m2m_db_table())
+                output.append(query % {'sequence':sequence_name,
+                                       'table':f.m2m_db_table()})
+        return output
+
 class DatabaseWrapper(BaseDatabaseWrapper):
     ops = DatabaseOperations()
 
@@ -244,24 +261,6 @@ def get_sequence_name(table):
     name_length = DatabaseOperations().max_name_length() - 3
     return '%s_SQ' % util.truncate_name(table, name_length).upper()
 
-def get_sql_sequence_reset(style, model_list):
-    "Returns a list of the SQL statements to reset sequences for the given models."
-    from django.db import models
-    output = []
-    query = _get_sequence_reset_sql()
-    for model in model_list:
-        for f in model._meta.fields:
-            if isinstance(f, models.AutoField):
-                sequence_name = get_sequence_name(model._meta.db_table)
-                output.append(query % {'sequence':sequence_name,
-                                       'table':model._meta.db_table})
-                break # Only one AutoField is allowed per model, so don't bother continuing.
-        for f in model._meta.many_to_many:
-            sequence_name = get_sequence_name(f.m2m_db_table())
-            output.append(query % {'sequence':sequence_name,
-                                   'table':f.m2m_db_table()})
-    return output
-
 def get_trigger_name(table):
     name_length = DatabaseOperations().max_name_length() - 3
     return '%s_TR' % util.truncate_name(table, name_length).upper()

django/db/backends/postgresql/base.py

@@ -124,6 +124,35 @@ class DatabaseOperations(BaseDatabaseOperations):
         else:
             return []
 
+    def sequence_reset_sql(self, style, model_list):
+        from django.db import models
+        output = []
+        for model in model_list:
+            # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
+            # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
+            # if there are records (as the max pk value is already in use), otherwise set it to false.
+            for f in model._meta.fields:
+                if isinstance(f, models.AutoField):
+                    output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+                        (style.SQL_KEYWORD('SELECT'),
+                        style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))),
+                        style.SQL_FIELD(quote_name(f.column)),
+                        style.SQL_FIELD(quote_name(f.column)),
+                        style.SQL_KEYWORD('IS NOT'),
+                        style.SQL_KEYWORD('FROM'),
+                        style.SQL_TABLE(quote_name(model._meta.db_table))))
+                    break # Only one AutoField is allowed per model, so don't bother continuing.
+            for f in model._meta.many_to_many:
+                output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+                    (style.SQL_KEYWORD('SELECT'),
+                    style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())),
+                    style.SQL_FIELD(quote_name('id')),
+                    style.SQL_FIELD(quote_name('id')),
+                    style.SQL_KEYWORD('IS NOT'),
+                    style.SQL_KEYWORD('FROM'),
+                    style.SQL_TABLE(f.m2m_db_table())))
+        return output
+
 class DatabaseWrapper(BaseDatabaseWrapper):
     ops = DatabaseOperations()
 
@@ -185,36 +214,6 @@ def dictfetchall(cursor):
 def get_start_transaction_sql():
     return "BEGIN;"
 
-def get_sql_sequence_reset(style, model_list):
-    "Returns a list of the SQL statements to reset sequences for the given models."
-    from django.db import models
-    output = []
-    for model in model_list:
-        # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
-        # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
-        # if there are records (as the max pk value is already in use), otherwise set it to false.
-        for f in model._meta.fields:
-            if isinstance(f, models.AutoField):
-                output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
-                    (style.SQL_KEYWORD('SELECT'),
-                    style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))),
-                    style.SQL_FIELD(quote_name(f.column)),
-                    style.SQL_FIELD(quote_name(f.column)),
-                    style.SQL_KEYWORD('IS NOT'),
-                    style.SQL_KEYWORD('FROM'),
-                    style.SQL_TABLE(quote_name(model._meta.db_table))))
-                break # Only one AutoField is allowed per model, so don't bother continuing.
-        for f in model._meta.many_to_many:
-            output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
-                (style.SQL_KEYWORD('SELECT'),
-                style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())),
-                style.SQL_FIELD(quote_name('id')),
-                style.SQL_FIELD(quote_name('id')),
-                style.SQL_KEYWORD('IS NOT'),
-                style.SQL_KEYWORD('FROM'),
-                style.SQL_TABLE(f.m2m_db_table())))
-    return output
-
 def typecast_string(s):
     """
     Cast all returned strings to unicode strings.

django/db/backends/postgresql_psycopg2/base.py

@@ -86,6 +86,35 @@ class DatabaseOperations(BaseDatabaseOperations):
         else:
             return []
 
+    def sequence_reset_sql(self, style, model_list):
+        from django.db import models
+        output = []
+        for model in model_list:
+            # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
+            # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
+            # if there are records (as the max pk value is already in use), otherwise set it to false.
+            for f in model._meta.fields:
+                if isinstance(f, models.AutoField):
+                    output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+                        (style.SQL_KEYWORD('SELECT'),
+                        style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))),
+                        style.SQL_FIELD(quote_name(f.column)),
+                        style.SQL_FIELD(quote_name(f.column)),
+                        style.SQL_KEYWORD('IS NOT'),
+                        style.SQL_KEYWORD('FROM'),
+                        style.SQL_TABLE(quote_name(model._meta.db_table))))
+                    break # Only one AutoField is allowed per model, so don't bother continuing.
+            for f in model._meta.many_to_many:
+                output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
+                    (style.SQL_KEYWORD('SELECT'),
+                    style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())),
+                    style.SQL_FIELD(quote_name('id')),
+                    style.SQL_FIELD(quote_name('id')),
+                    style.SQL_KEYWORD('IS NOT'),
+                    style.SQL_KEYWORD('FROM'),
+                    style.SQL_TABLE(f.m2m_db_table())))
+        return output
+
 class DatabaseWrapper(BaseDatabaseWrapper):
     ops = DatabaseOperations()
 
@@ -139,36 +168,6 @@ dictfetchall = util.dictfetchall
 def get_start_transaction_sql():
     return "BEGIN;"
 
-def get_sql_sequence_reset(style, model_list):
-    "Returns a list of the SQL statements to reset sequences for the given models."
-    from django.db import models
-    output = []
-    for model in model_list:
-        # Use `coalesce` to set the sequence for each model to the max pk value if there are records,
-        # or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
-        # if there are records (as the max pk value is already in use), otherwise set it to false.
-        for f in model._meta.fields:
-            if isinstance(f, models.AutoField):
-                output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
-                    (style.SQL_KEYWORD('SELECT'),
-                    style.SQL_FIELD(quote_name('%s_%s_seq' % (model._meta.db_table, f.column))),
-                    style.SQL_FIELD(quote_name(f.column)),
-                    style.SQL_FIELD(quote_name(f.column)),
-                    style.SQL_KEYWORD('IS NOT'),
-                    style.SQL_KEYWORD('FROM'),
-                    style.SQL_TABLE(quote_name(model._meta.db_table))))
-                break # Only one AutoField is allowed per model, so don't bother continuing.
-        for f in model._meta.many_to_many:
-            output.append("%s setval('%s', coalesce(max(%s), 1), max(%s) %s null) %s %s;" % \
-                (style.SQL_KEYWORD('SELECT'),
-                style.SQL_FIELD(quote_name('%s_id_seq' % f.m2m_db_table())),
-                style.SQL_FIELD(quote_name('id')),
-                style.SQL_FIELD(quote_name('id')),
-                style.SQL_KEYWORD('IS NOT'),
-                style.SQL_KEYWORD('FROM'),
-                style.SQL_TABLE(f.m2m_db_table())))
-    return output
-
 OPERATOR_MAPPING = {
     'exact': '= %s',
     'iexact': 'ILIKE %s',

django/db/backends/sqlite3/base.py

@@ -134,11 +134,6 @@ def _sqlite_extract(lookup_type, dt):
 def get_start_transaction_sql():
     return "BEGIN;"
 
-def get_sql_sequence_reset(style, model_list):
-    "Returns a list of the SQL statements to reset sequences for the given models."
-    # No sequence reset required
-    return []
-
 def _sqlite_date_trunc(lookup_type, dt):
     try:
         dt = util.typecast_timestamp(dt)