Uploading files

move_db.py

@@ -0,0 +1,76 @@
+# The following code is tested on Django 1.7
+import django
+import sys
+import logging
+
+from django.apps import apps
+from django.db.migrations.recorder import MigrationRecorder
+if django.get_version() > '1.7':
+    from django.core.serializers import sort_dependencies
+else:
+    from django.core.management.commands.dumpdata import sort_dependencies
+
+
+LOG_FORMAT = '%(asctime)s|%(levelname)s|%(message)s'
+logging.basicConfig(stream=sys.stdout, level=logging.INFO, format=LOG_FORMAT)
+logger = logging.getLogger(__name__)
+
+
+def copy(model):
+    table_name = model._meta.db_table
+    logger.info('Start import %s into slave' % table_name)
+
+    table_objects = model.objects.all()
+    for t in table_objects:
+        t.save(using='slave')
+
+    logger.info('Successfuly imported %s into slave' % table_name)
+
+'''
+Please note that the id for many to many objects might be diffrent from source table.
+This is because id is not specified in the add method.
+'''
+def copy_m2m(model, m2m_field):
+    table_name = m2m_field.rel.through._meta.db_table
+    field_name = m2m_field.name
+    to_model = m2m_field.rel.to
+    pk_name = model._meta.pk.name
+    child_pk_name = to_model._meta.pk.name
+
+    logger.info('Start import %s into slave' % table_name)
+
+    for o in model.objects.all():
+        pk_value = getattr(o, pk_name)
+        new_o = model.objects.using('slave').get(**{pk_name: pk_value})
+        for child in getattr(o, field_name).all():
+            child_pk_value = getattr(child, child_pk_name)
+            new_child = to_model.objects.using('slave').get(**{child_pk_name: child_pk_value})
+            getattr(new_o, field_name).add(new_child)
+
+    logger.info('Successfuly imported %s into slave' % table_name)
+
+
+def run():
+    logger.info('Start move data into slave')
+
+    app_configs = apps.get_app_configs()
+    app_list = [(a, None) for a in app_configs]
+    models = sort_dependencies(app_list)
+    models_with_m2m = []
+
+    for m in models:
+        copy(m)
+        if m._meta.many_to_many:
+            models_with_m2m.append(m)
+
+    # Migration model needs to copy separately as it is not in the INSTALLED_APPS
+    copy(MigrationRecorder.Migration)
+
+    # re-create object in ManyToManyField
+    for m in models_with_m2m:
+        for field in m._meta.many_to_many:
+            # data for field that has specific through model should have been copied in earlier steps
+            if field.rel.through._meta.auto_created:
+                copy_m2m(m, field)
+
+    logger.info('Successfully moved data into slave')