Fixed #3790 -- Fixed a problem with sequence resetting during fixture loads when using Postgres. Thanks to Jon Ballard and scott@staplefish.com for the report, and to Zach Thompson for suggesting a solution.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4937 bcc190cf-cafb-0310-a4f2-bffc1f526a37

AUTHORS

@@ -192,6 +192,7 @@ answer newbie questions, and generally made Django that much better:
     Ville Säävuori <http://www.unessa.net/>
     Tyson Tate <tyson@fallingbullets.com>
     thebjorn <bp@datakortet.no>
+    Zach Thompson <zthompson47@gmail.com>
     Tom Tobin
     Joe Topjian <http://joe.terrarum.net/geek/code/python/django/>
     torne-django@wolfpuppy.org.uk

django/core/management.py

@@ -410,30 +410,10 @@ get_sql_initial_data.help_doc = "RENAMED: see 'sqlcustom'"
 get_sql_initial_data.args = ''
 
 def get_sql_sequence_reset(app):
-    "Returns a list of the SQL statements to reset PostgreSQL sequences for the given app."
+    "Returns a list of the SQL statements to reset sequences for the given app."
     from django.db import backend, models
-    output = []
+    return backend.get_sql_sequence_reset(style, models.get_models(app))
-    for model in models.get_models(app):
+get_sql_sequence_reset.help_doc = "Prints the SQL statements for resetting sequences for the given app name(s)."
-        for f in model._meta.fields:
-            if isinstance(f, models.AutoField):
-                output.append("%s setval('%s', (%s max(%s) %s %s));" % \
-                    (style.SQL_KEYWORD('SELECT'),
-                    style.SQL_FIELD('%s_%s_seq' % (model._meta.db_table, f.column)),
-                    style.SQL_KEYWORD('SELECT'),
-                    style.SQL_FIELD(backend.quote_name(f.column)),
-                    style.SQL_KEYWORD('FROM'),
-                    style.SQL_TABLE(backend.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', (%s max(%s) %s %s));" % \
-                (style.SQL_KEYWORD('SELECT'),
-                style.SQL_FIELD('%s_id_seq' % f.m2m_db_table()),
-                style.SQL_KEYWORD('SELECT'),
-                style.SQL_FIELD(backend.quote_name('id')),
-                style.SQL_KEYWORD('FROM'),
-                style.SQL_TABLE(f.m2m_db_table())))
-    return output
-get_sql_sequence_reset.help_doc = "Prints the SQL statements for resetting PostgreSQL sequences for the given app name(s)."
 get_sql_sequence_reset.args = APP_ARGS
 
 def get_sql_indexes(app):
@@ -1333,13 +1313,14 @@ def load_data(fixture_labels, verbosity=1):
     "Installs the provided fixture file(s) as data in the database."
     from django.db.models import get_apps
     from django.core import serializers
-    from django.db import connection, transaction
+    from django.db import connection, transaction, backend
     from django.conf import settings
     import sys
 
     # Keep a count of the installed objects and fixtures
     count = [0,0]
-
+    models = set()
+    
     humanize = lambda dirname: dirname and "'%s'" % dirname or 'absolute path'
 
     # Get a cursor (even though we don't need one yet). This has
@@ -1401,6 +1382,7 @@ def load_data(fixture_labels, verbosity=1):
                             objects =  serializers.deserialize(format, fixture)
                             for obj in objects:
                                 count[0] += 1
+                                models.add(obj.object.__class__)
                                 obj.save()
                             label_found = True
                         except Exception, e:
@@ -1422,6 +1404,12 @@ def load_data(fixture_labels, verbosity=1):
     else:
         if verbosity > 0:
             print "Installed %d object(s) from %d fixture(s)" % tuple(count)
+        sequence_sql = backend.get_sql_sequence_reset(style, models)
+        if sequence_sql:
+            if verbosity > 1:
+                print "Resetting sequences"
+            for line in sequence_sql:
+                cursor.execute(line)
     transaction.commit()
     transaction.leave_transaction_management()
 

django/db/backends/ado_mssql/base.py

@@ -151,6 +151,11 @@ def get_sql_flush(sql_styler, full_table_list):
                  sql_styler.SQL_FIELD(quote_name(table))
                  )  for table in full_table_list]
 
+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

@@ -40,5 +40,6 @@ get_deferrable_sql = complain
 get_fulltext_search_sql = complain
 get_drop_foreignkey_sql = complain
 get_sql_flush = complain
+get_sql_sequence_reset = complain
 
 OPERATOR_MAPPING = {}

django/db/backends/mysql/base.py

@@ -215,6 +215,11 @@ def get_sql_flush(style, tables, sequences):
     else:
         return []
 
+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

@@ -217,6 +217,11 @@ def get_sql_flush(style, tables, sequences):
     else:
         return []
 
+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

@@ -134,6 +134,10 @@ def get_sql_flush(style, tables, sequences):
              style.SQL_FIELD(quote_name(table))
              )  for table in tables]
 
+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',

django/db/backends/postgresql/base.py

@@ -213,6 +213,30 @@ def get_sql_flush(style, tables, sequences):
     else:
         return []
 
+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:
+        for f in model._meta.fields:
+            if isinstance(f, models.AutoField):
+                output.append("%s setval('%s', (%s max(%s) %s %s));" % \
+                    (style.SQL_KEYWORD('SELECT'),
+                    style.SQL_FIELD('%s_%s_seq' % (model._meta.db_table, f.column)),
+                    style.SQL_KEYWORD('SELECT'),
+                    style.SQL_FIELD(quote_name(f.column)),
+                    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', (%s max(%s) %s %s));" % \
+                (style.SQL_KEYWORD('SELECT'),
+                style.SQL_FIELD('%s_id_seq' % f.m2m_db_table()),
+                style.SQL_KEYWORD('SELECT'),
+                style.SQL_FIELD(quote_name('id')),
+                style.SQL_KEYWORD('FROM'),
+                style.SQL_TABLE(f.m2m_db_table())))
+    return output
         
 # Register these custom typecasts, because Django expects dates/times to be
 # in Python's native (standard-library) datetime/time format, whereas psycopg

django/db/backends/postgresql_psycopg2/base.py

@@ -169,6 +169,31 @@ def get_sql_flush(style, tables, sequences):
         return sql
     else:
         return []
+
+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:
+        for f in model._meta.fields:
+            if isinstance(f, models.AutoField):
+                output.append("%s setval('%s', (%s max(%s) %s %s));" % \
+                    (style.SQL_KEYWORD('SELECT'),
+                    style.SQL_FIELD('%s_%s_seq' % (model._meta.db_table, f.column)),
+                    style.SQL_KEYWORD('SELECT'),
+                    style.SQL_FIELD(quote_name(f.column)),
+                    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', (%s max(%s) %s %s));" % \
+                (style.SQL_KEYWORD('SELECT'),
+                style.SQL_FIELD('%s_id_seq' % f.m2m_db_table()),
+                style.SQL_KEYWORD('SELECT'),
+                style.SQL_FIELD(quote_name('id')),
+                style.SQL_KEYWORD('FROM'),
+                style.SQL_TABLE(f.m2m_db_table())))
+    return output
         
 OPERATOR_MAPPING = {
     'exact': '= %s',

django/db/backends/sqlite3/base.py

@@ -170,6 +170,11 @@ def get_sql_flush(style, tables, sequences):
     # get_sql_flush() implementations). Just return SQL at this point
     return sql
 
+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)

docs/django-admin.txt

@@ -366,7 +366,7 @@ Prints the DROP TABLE SQL, then the CREATE TABLE SQL, for the given appnames.
 sqlsequencereset [appname appname ...]
 ----------------------------------------------
 
-Prints the SQL statements for resetting PostgreSQL sequences for the given
+Prints the SQL statements for resetting sequences for the given
 appnames.
 
 See http://simon.incutio.com/archive/2004/04/21/postgres for more information.

tests/regressiontests/fixtures_regress/fixtures/sequence.json

@@ -0,0 +1,10 @@
+[
+    {
+        "pk": "1", 
+        "model": "fixtures_regress.animal", 
+        "fields": {
+            "name": "Lion", 
+            "latin_name": "Panthera leo"
+        }
+    }
+]

tests/regressiontests/fixtures_regress/models.py

@@ -0,0 +1,22 @@
+from django.db import models
+
+class Animal(models.Model):
+    name = models.CharField(maxlength=150)
+    latin_name = models.CharField(maxlength=150)
+
+    def __str__(self):
+        return self.common_name    
+
+__test__ = {'API_TESTS':"""
+>>> from django.core import management
+
+# Load a fixture that uses PK=1
+>>> management.load_data(['sequence'], verbosity=0)
+        
+# Create a new animal. Without a sequence reset, this new object
+# will take a PK of 1 (on Postgres), and the save will fail.
+# This is a regression test for ticket #3790.
+>>> animal = Animal(name='Platypus', latin_name='Ornithorhynchus anatinus')
+>>> animal.save()
+
+"""}