""" sqldiff.py - Prints the (approximated) difference between models and database TODO: - better support for relations - better support for constraints (mainly postgresql?) - support for table spaces with postgresql KNOWN ISSUES: - MySQL has by far the most problems with introspection. Please be carefull when using MySQL with sqldiff. - Booleans are reported back as Integers, so there's know way to know if there was a real change. - Varchar sizes are reported back without unicode support so there size may change in comparison to the real length of the varchar. - Some of the 'fixes' to counter these problems might create false positives or false negatives. """ from django.core.management.base import BaseCommand from django.core.management import sql as _sql from django.core.management import CommandError from django.core.management.color import no_style from django.db import transaction, connection from django.db.models.fields import IntegerField from optparse import make_option ORDERING_FIELD = IntegerField('_order', null=True) def flatten(l, ltypes=(list, tuple)): ltype = type(l) l = list(l) i = 0 while i < len(l): while isinstance(l[i], ltypes): if not l[i]: l.pop(i) i -= 1 break else: l[i:i + 1] = l[i] i += 1 return ltype(l) class SQLDiff(object): DATA_TYPES_REVERSE_OVERRIDE = { } DIFF_TYPES = [ 'comment', 'table-missing-in-db', 'field-missing-in-db', 'field-missing-in-model', 'index-missing-in-db', 'index-missing-in-model', 'unique-missing-in-db', 'unique-missing-in-model', 'field-type-differ', 'field-parameter-differ', ] DIFF_TEXTS = { 'comment': 'comment: %(0)s', 'table-missing-in-db': "table '%(0)s' missing in database", 'field-missing-in-db' : "field '%(1)s' defined in model but missing in database", 'field-missing-in-model' : "field '%(1)s' defined in database but missing in model", 'index-missing-in-db' : "field '%(1)s' INDEX defined in model but missing in database", 'index-missing-in-model' : "field '%(1)s' INDEX defined in database schema but missing in model", 'unique-missing-in-db' : "field '%(1)s' UNIQUE defined in model but missing in database", 'unique-missing-in-model' : "field '%(1)s' UNIQUE defined in database schema but missing in model", 'field-type-differ' : "field '%(1)s' not of same type: db='%(3)s', model='%(2)s'", 'field-parameter-differ' : "field '%(1)s' parameters differ: db='%(3)s', model='%(2)s'", } SQL_FIELD_MISSING_IN_DB = lambda self, style, qn, args: "%s %s\n\t%s %s %s;" % (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(args[0])), style.SQL_KEYWORD('ADD'), style.SQL_FIELD(qn(args[1])), style.SQL_COLTYPE(args[2])) SQL_FIELD_MISSING_IN_MODEL = lambda self, style, qn, args: "%s %s\n\t%s %s;" % (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(args[0])), style.SQL_KEYWORD('DROP COLUMN'), style.SQL_FIELD(qn(args[1]))) SQL_INDEX_MISSING_IN_DB = lambda self, style, qn, args: "%s %s\n\t%s %s (%s);" % (style.SQL_KEYWORD('CREATE INDEX'), style.SQL_TABLE(qn("%s_idx" % '_'.join(args[0:2]))), style.SQL_KEYWORD('ON'), style.SQL_TABLE(qn(args[0])), style.SQL_FIELD(qn(args[1]))) # FIXME: need to lookup index name instead of just appending _idx to table + fieldname SQL_INDEX_MISSING_IN_MODEL = lambda self, style, qn, args: "%s %s;" % (style.SQL_KEYWORD('DROP INDEX'), style.SQL_TABLE(qn("%s_idx" % '_'.join(args[0:2])))) SQL_UNIQUE_MISSING_IN_DB = lambda self, style, qn, args: "%s %s\n\t%s %s (%s);" % (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(args[0])), style.SQL_KEYWORD('ADD'), style.SQL_KEYWORD('UNIQUE'), style.SQL_FIELD(qn(args[1]))) # FIXME: need to lookup unique constraint name instead of appending _key to table + fieldname SQL_UNIQUE_MISSING_IN_MODEL = lambda self, style, qn, args: "%s %s\n\t%s %s %s;" % (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(args[0])), style.SQL_KEYWORD('DROP'), style.SQL_KEYWORD('CONSTRAINT'), style.SQL_TABLE(qn("%s_key" % ('_'.join(args[:2]))))) SQL_FIELD_TYPE_DIFFER = lambda self, style, qn, args: "%s %s\n\t%s %s %s;" % (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(args[0])), style.SQL_KEYWORD("MODIFY"), style.SQL_FIELD(qn(args[1])), style.SQL_COLTYPE(args[2])) SQL_FIELD_PARAMETER_DIFFER = lambda self, style, qn, args: "%s %s\n\t%s %s %s;" % (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(args[0])), style.SQL_KEYWORD("MODIFY"), style.SQL_FIELD(qn(args[1])), style.SQL_COLTYPE(args[2])) SQL_COMMENT = lambda self, style, qn, args: style.NOTICE('-- Comment: %s' % style.SQL_TABLE(args[0])) SQL_TABLE_MISSING_IN_DB = lambda self, style, qn, args: style.NOTICE('-- Table missing: %s' % args[0]) def __init__(self, app_models, options): self.app_models = app_models self.options = options self.dense = options.get('dense_output', False) try: self.introspection = connection.introspection except AttributeError: from django.db import get_introspection_module self.introspection = get_introspection_module() self.cursor = connection.cursor() self.django_tables = self.get_django_tables(options.get('only_existing', True)) self.db_tables = self.introspection.get_table_list(self.cursor) self.differences = [] self.unknown_db_fields = {} self.DIFF_SQL = { 'comment': self.SQL_COMMENT, 'table-missing-in-db': self.SQL_TABLE_MISSING_IN_DB, 'field-missing-in-db': self.SQL_FIELD_MISSING_IN_DB, 'field-missing-in-model': self.SQL_FIELD_MISSING_IN_MODEL, 'index-missing-in-db': self.SQL_INDEX_MISSING_IN_DB, 'index-missing-in-model': self.SQL_INDEX_MISSING_IN_MODEL, 'unique-missing-in-db': self.SQL_UNIQUE_MISSING_IN_DB, 'unique-missing-in-model': self.SQL_UNIQUE_MISSING_IN_MODEL, 'field-type-differ': self.SQL_FIELD_TYPE_DIFFER, 'field-parameter-differ': self.SQL_FIELD_PARAMETER_DIFFER, } def add_app_model_marker(self, app_label, model_name): self.differences.append((app_label, model_name, [])) def add_difference(self, diff_type, *args): assert diff_type in self.DIFF_TYPES, 'Unknown difference type' self.differences[-1][-1].append((diff_type, args)) def get_django_tables(self, only_existing): try: django_tables = self.introspection.django_table_names(only_existing=only_existing) except AttributeError: # backwards compatibility for before introspection refactoring (r8296) try: django_tables = _sql.django_table_names(only_existing=only_existing) except AttributeError: # backwards compatibility for before svn r7568 django_tables = _sql.django_table_list(only_existing=only_existing) return django_tables def sql_to_dict(self, query,param): """ sql_to_dict(query, param) -> list of dicts code from snippet at http://www.djangosnippets.org/snippets/1383/ """ cursor = connection.cursor() cursor.execute(query,param) fieldnames = [name[0] for name in cursor.description] result = [] for row in cursor.fetchall(): rowset = [] for field in zip(fieldnames, row): rowset.append(field) result.append(dict(rowset)) return result def get_field_model_type(self, field): return field.db_type() def get_field_db_type(self, description, field=None, table_name=None): from django.db import models # DB-API cursor.description #(name, type_code, display_size, internal_size, precision, scale, null_ok) = description type_code = description[1] if type_code in self.DATA_TYPES_REVERSE_OVERRIDE: reverse_type = self.DATA_TYPES_REVERSE_OVERRIDE[type_code] else: try: try: reverse_type = self.introspection.data_types_reverse[type_code] except AttributeError: # backwards compatibility for before introspection refactoring (r8296) reverse_type = self.introspection.DATA_TYPES_REVERSE.get(type_code) except KeyError: # type_code not found in data_types_reverse map key = (self.differences[-1][:2], description[:2]) if key not in self.unknown_db_fields: self.unknown_db_fields[key] = 1 self.add_difference('comment', "Unknown database type for field '%s' (%s)" % (description[0], type_code)) return None kwargs = {} if isinstance(reverse_type, tuple): kwargs.update(reverse_type[1]) reverse_type = reverse_type[0] if reverse_type == "CharField" and description[3]: kwargs['max_length'] = description[3] if reverse_type == "DecimalField": kwargs['max_digits'] = description[4] kwargs['decimal_places'] = description[5] if description[6]: kwargs['blank'] = True if not reverse_type in ('TextField', 'CharField'): kwargs['null'] = True field_db_type = getattr(models, reverse_type)(**kwargs).db_type() return field_db_type def strip_parameters(self, field_type): if field_type: return field_type.split(" ")[0].split("(")[0] return field_type def find_unique_missing_in_db(self, meta, table_indexes, table_name): for field in meta.fields: if field.unique: attname = field.db_column or field.attname if attname in table_indexes and table_indexes[attname]['unique']: continue self.add_difference('unique-missing-in-db', table_name, attname) def find_unique_missing_in_model(self, meta, table_indexes, table_name): # TODO: Postgresql does not list unique_togethers in table_indexes # MySQL does fields = dict([(field.db_column or field.name, field.unique) for field in meta.fields]) for att_name, att_opts in table_indexes.iteritems(): if att_opts['unique'] and att_name in fields and not fields[att_name]: if att_name in flatten(meta.unique_together): continue self.add_difference('unique-missing-in-model', table_name, att_name) def find_index_missing_in_db(self, meta, table_indexes, table_name): for field in meta.fields: if field.db_index: attname = field.db_column or field.attname if not attname in table_indexes: self.add_difference('index-missing-in-db', table_name, attname) def find_index_missing_in_model(self, meta, table_indexes, table_name): fields = dict([(field.name, field) for field in meta.fields]) for att_name, att_opts in table_indexes.iteritems(): if att_name in fields: field = fields[att_name] if field.db_index: continue if att_opts['primary_key'] and field.primary_key: continue if att_opts['unique'] and field.unique: continue if att_opts['unique'] and att_name in flatten(meta.unique_together): continue self.add_difference('index-missing-in-model', table_name, att_name) def find_field_missing_in_model(self, fieldmap, table_description, table_name): for row in table_description: if row[0] not in fieldmap: self.add_difference('field-missing-in-model', table_name, row[0]) def find_field_missing_in_db(self, fieldmap, table_description, table_name): db_fields = [row[0] for row in table_description] for field_name, field in fieldmap.iteritems(): if field_name not in db_fields: self.add_difference('field-missing-in-db', table_name, field_name, field.db_type()) def find_field_type_differ(self, meta, table_description, table_name, func=None): db_fields = dict([(row[0], row) for row in table_description]) for field in meta.fields: if field.name not in db_fields: continue description = db_fields[field.name] model_type = self.strip_parameters(self.get_field_model_type(field)) db_type = self.strip_parameters(self.get_field_db_type(description, field)) # use callback function if defined if func: model_type, db_type = func(field, description, model_type, db_type) if not model_type==db_type: self.add_difference('field-type-differ', table_name, field.name, model_type, db_type) def find_field_parameter_differ(self, meta, table_description, table_name, func=None): db_fields = dict([(row[0], row) for row in table_description]) for field in meta.fields: if field.name not in db_fields: continue description = db_fields[field.name] model_type = self.get_field_model_type(field) db_type = self.get_field_db_type(description, field, table_name) if not self.strip_parameters(model_type)==self.strip_parameters(db_type): continue # use callback function if defined if func: model_type, db_type = func(field, description, model_type, db_type) if not model_type==db_type: self.add_difference('field-parameter-differ', table_name, field.name, model_type, db_type) @transaction.commit_manually def find_differences(self): cur_app_label = None for app_model in self.app_models: meta = app_model._meta table_name = meta.db_table app_label = meta.app_label if cur_app_label!=app_label: # Marker indicating start of difference scan for this table_name self.add_app_model_marker(app_label, app_model.__name__) #if not table_name in self.django_tables: if not table_name in self.db_tables: # Table is missing from database self.add_difference('table-missing-in-db', table_name) continue table_indexes = self.introspection.get_indexes(self.cursor, table_name) fieldmap = dict([(field.db_column or field.get_attname(), field) for field in meta.fields]) # add ordering field if model uses order_with_respect_to if meta.order_with_respect_to: fieldmap['_order'] = ORDERING_FIELD try: table_description = self.introspection.get_table_description(self.cursor, table_name) except Exception, e: model_diffs.append((app_model.__name__, [str(e).strip()])) transaction.rollback() # reset transaction continue # Fields which are defined in database but not in model # 1) find: 'unique-missing-in-model' self.find_unique_missing_in_model(meta, table_indexes, table_name) # 2) find: 'index-missing-in-model' self.find_index_missing_in_model(meta, table_indexes, table_name) # 3) find: 'field-missing-in-model' self.find_field_missing_in_model(fieldmap, table_description, table_name) # Fields which are defined in models but not in database # 4) find: 'field-missing-in-db' self.find_field_missing_in_db(fieldmap, table_description, table_name) # 5) find: 'unique-missing-in-db' self.find_unique_missing_in_db(meta, table_indexes, table_name) # 6) find: 'index-missing-in-db' self.find_index_missing_in_db(meta, table_indexes, table_name) # Fields which have a different type or parameters # 7) find: 'type-differs' self.find_field_type_differ(meta, table_description, table_name) # 8) find: 'type-parameter-differs' self.find_field_parameter_differ(meta, table_description, table_name) def print_diff(self, style=no_style()): """ print differences to stdout """ if self.options.get('sql', True): self.print_diff_sql(style) else: self.print_diff_text(style) def print_diff_text(self, style): cur_app_label = None for app_label, model_name, diffs in self.differences: if not diffs: continue if not self.dense and cur_app_label != app_label: print style.NOTICE("+ Application:"), style.SQL_TABLE(app_label) cur_app_label = app_label if not self.dense: print style.NOTICE("|-+ Differences for model:"), style.SQL_TABLE(model_name) for diff in diffs: diff_type, diff_args = diff text = self.DIFF_TEXTS[diff_type] % dict((str(i), style.SQL_TABLE(e)) for i, e in enumerate(diff_args)) text = "'".join(i%2==0 and style.ERROR_OUTPUT(e) or e for i, e in enumerate(text.split("'"))) if not self.dense: print style.NOTICE("|--+"), text else: print style.NOTICE("App"), style.SQL_TABLE(app_name), style.NOTICE('Model'), style.SQL_TABLE(model_name), text def print_diff_sql(self, style): cur_app_label = None qn = connection.ops.quote_name print style.SQL_KEYWORD("BEGIN;") for app_label, model_name, diffs in self.differences: if not diffs: continue if not self.dense and cur_app_label != app_label: print style.NOTICE("-- Application: %s" % style.SQL_TABLE(app_label)) cur_app_label = app_label if not self.dense: print style.NOTICE("-- Model: %s" % style.SQL_TABLE(model_name)) for diff in diffs: diff_type, diff_args = diff text = self.DIFF_SQL[diff_type](style, qn, diff_args) if self.dense: text = text.replace("\n\t", " ") print text print style.SQL_KEYWORD("COMMIT;") class GenericSQLDiff(SQLDiff): pass class MySQLDiff(SQLDiff): # All the MySQL hacks together create something of a problem # Fixing one bug in MySQL creates another issue. So just keep in mind # that this is way unreliable for MySQL atm. def get_field_db_type(self, description, field=None, table_name=None): from MySQLdb.constants import FIELD_TYPE # weird bug? in mysql db-api where it returns three times the correct value for field length # if i remember correctly it had something todo with unicode strings # TODO: Fix this is a more meaningful and better understood manner description = list(description) if description[1] not in [FIELD_TYPE.TINY, FIELD_TYPE.SHORT]: # exclude tinyints from conversion. description[3] = description[3]/3 description[4] = description[4]/3 db_type = super(MySQLDiff, self).get_field_db_type(description) if not db_type: return if field: if field.primary_key and db_type=='integer': db_type += ' AUTO_INCREMENT' # MySQL isn't really sure about char's and varchar's like sqlite field_type = self.get_field_model_type(field) # Fix char/varchar inconsistencies if self.strip_parameters(field_type)=='char' and self.strip_parameters(db_type)=='varchar': db_type = db_type.lstrip("var") # They like to call 'bool's 'tinyint(1)' and introspection makes that a integer # just convert it back to it's proper type, a bool is a bool and nothing else. if db_type=='integer' and description[1]==FIELD_TYPE.TINY and description[4]==1: db_type = 'bool' if db_type=='integer' and description[1]==FIELD_TYPE.SHORT: db_type = 'smallint UNSIGNED' # FIXME: what about if it's not UNSIGNED ? return db_type class SqliteSQLDiff(SQLDiff): # Unique does not seem to be implied on Sqlite for Primary_key's # if this is more generic among databases this might be usefull # to add to the superclass's find_unique_missing_in_db method def find_unique_missing_in_db(self, meta, table_indexes, table_name): for field in meta.fields: if field.unique: attname = field.attname if attname in table_indexes and table_indexes[attname]['unique']: continue if table_indexes[attname]['primary_key']: continue self.add_difference('unique-missing-in-db', table_name, attname) # Finding Indexes by using the get_indexes dictionary doesn't seem to work # for sqlite. def find_index_missing_in_db(self, meta, table_indexes, table_name): pass def find_index_missing_in_model(self, meta, table_indexes, table_name): pass def get_field_db_type(self, description, field=None, table_name=None): db_type = super(SqliteSQLDiff, self).get_field_db_type(description) if not db_type: return if field: field_type = self.get_field_model_type(field) # Fix char/varchar inconsistencies if self.strip_parameters(field_type)=='char' and self.strip_parameters(db_type)=='varchar': db_type = db_type.lstrip("var") return db_type class PostgresqlSQLDiff(SQLDiff): DATA_TYPES_REVERSE_OVERRIDE = { 20: 'IntegerField', 1042: 'CharField', } # Hopefully in the future we can add constraint checking and other more # advanced checks based on this database. SQL_LOAD_CONSTRAINTS = """ SELECT nspname, relname, conname, attname, pg_get_constraintdef(pg_constraint.oid) FROM pg_constraint INNER JOIN pg_attribute ON pg_constraint.conrelid = pg_attribute.attrelid AND pg_attribute.attnum = any(pg_constraint.conkey) INNER JOIN pg_class ON conrelid=pg_class.oid INNER JOIN pg_namespace ON pg_namespace.oid=pg_class.relnamespace ORDER BY CASE WHEN contype='f' THEN 0 ELSE 1 END,contype,nspname,relname,conname; """ SQL_FIELD_TYPE_DIFFER = lambda self, style, qn, args: "%s %s\n\t%s %s %s %s;" % (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(args[0])), style.SQL_KEYWORD('ALTER'), style.SQL_FIELD(qn(args[1])), style.SQL_KEYWORD("TYPE"), style.SQL_COLTYPE(args[2])) SQL_FIELD_PARAMETER_DIFFER = lambda self, style, qn, args: "%s %s\n\t%s %s %s %s;" % (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(args[0])), style.SQL_KEYWORD('ALTER'), style.SQL_FIELD(qn(args[1])), style.SQL_KEYWORD("TYPE"), style.SQL_COLTYPE(args[2])) def __init__(self, app_models, options): SQLDiff.__init__(self, app_models, options) self.check_constraints = {} self.load_constraints() def load_constraints(self): for dct in self.sql_to_dict(self.SQL_LOAD_CONSTRAINTS, []): key = (dct['nspname'], dct['relname'], dct['attname']) if 'CHECK' in dct['pg_get_constraintdef']: self.check_constraints[key] = dct def get_field_db_type(self, description, field=None, table_name=None): db_type = super(PostgresqlSQLDiff, self).get_field_db_type(description) if not db_type: return if field: if field.primary_key and db_type=='integer': db_type = 'serial' if table_name: tablespace = field.db_tablespace if tablespace=="": tablespace = "public" check_constraint = self.check_constraints.get((tablespace, table_name, field.attname),{}).get('pg_get_constraintdef', None) if check_constraint: check_constraint = check_constraint.replace("((", "(") check_constraint = check_constraint.replace("))", ")") check_constraint = '("'.join([')' in e and '" '.join(e.split(" ", 1)) or e for e in check_constraint.split("(")]) # TODO: might be more then one constraint in definition ? db_type += ' '+check_constraint return db_type """ def find_field_type_differ(self, meta, table_description, table_name): def callback(field, description, model_type, db_type): if field.primary_key and db_type=='integer': db_type = 'serial' return model_type, db_type super(PostgresqlSQLDiff, self).find_field_type_differs(meta, table_description, table_name, callback) """ DATABASE_SQLDIFF_CLASSES = { 'postgresql_psycopg2' : PostgresqlSQLDiff, 'postgresql': PostgresqlSQLDiff, 'mysql': MySQLDiff, 'sqlite3': SqliteSQLDiff, 'oracle': GenericSQLDiff } class Command(BaseCommand): option_list = BaseCommand.option_list + ( make_option('--all-applications', '-a', action='store_true', dest='all_applications', help="Automaticly include all application from INSTALLED_APPS."), make_option('--not-only-existing', '-e', action='store_false', dest='only_existing', help="Check all tables that exist in the database, not only tables that should exist based on models."), make_option('--dense-output', '-d', action='store_true', dest='dense_output', help="Shows the output in dense format, normally output is spreaded over multiple lines."), make_option('--output_text', '-t', action='store_false', dest='sql', default=True, help="Outputs the differences as descriptive text instead of SQL"), ) help = """Prints the (approximated) difference between models and fields in the database for the given app name(s). It indicates how columns in the database are different from the sql that would be generated by Django. This command is not a database migration tool. (Though it can certainly help) It's purpose is to show the current differences as a way to check/debug ur models compared to the real database tables and columns.""" output_transaction = False args = '' def handle(self, *app_labels, **options): from django.db import models from django.conf import settings if settings.DATABASE_ENGINE =='dummy': # This must be the "dummy" database backend, which means the user # hasn't set DATABASE_ENGINE. raise CommandError("Django doesn't know which syntax to use for your SQL statements,\n" + "because you haven't specified the DATABASE_ENGINE setting.\n" + "Edit your settings file and change DATABASE_ENGINE to something like 'postgresql' or 'mysql'.") if options.get('all_applications', False): app_models = models.get_models() else: if not app_labels: raise CommandError('Enter at least one appname.') try: app_list = [models.get_app(app_label) for app_label in app_labels] except (models.ImproperlyConfigured, ImportError), e: raise CommandError("%s. Are you sure your INSTALLED_APPS setting is correct?" % e) app_models = [] for app in app_list: app_models.extend(models.get_models(app)) if not app_models: raise CommandError('Unable to execute sqldiff no models founds.') cls = DATABASE_SQLDIFF_CLASSES.get(settings.DATABASE_ENGINE, GenericSQLDiff) sqldiff_instance = cls(app_models, options) sqldiff_instance.find_differences() sqldiff_instance.print_diff(self.style) return