from optparse import make_option from django.core.cache.backends.db import BaseDatabaseCache from django.core.management.base import LabelCommand, CommandError from django.db import connections, router, transaction, models, DEFAULT_DB_ALIAS from django.db.utils import DatabaseError from django.utils.encoding import force_text class Command(LabelCommand): help = "Creates the table needed to use the SQL cache backend." args = "" label = 'tablename' option_list = LabelCommand.option_list + ( make_option('--database', action='store', dest='database', default=DEFAULT_DB_ALIAS, help='Nominates a database onto ' 'which the cache table will be installed. ' 'Defaults to the "default" database.'), ) requires_model_validation = False def handle_label(self, tablename, **options): db = options.get('database') cache = BaseDatabaseCache(tablename, {}) if not router.allow_syncdb(db, cache.cache_model_class): return connection = connections[db] fields = ( # "key" is a reserved word in MySQL, so use "cache_key" instead. models.CharField(name='cache_key', max_length=255, unique=True, primary_key=True), models.TextField(name='value'), models.DateTimeField(name='expires', db_index=True), ) table_output = [] index_output = [] qn = connection.ops.quote_name for f in fields: field_output = [qn(f.name), f.db_type(connection=connection)] field_output.append("%sNULL" % (not f.null and "NOT " or "")) if f.primary_key: field_output.append("PRIMARY KEY") elif f.unique: field_output.append("UNIQUE") if f.db_index: unique = f.unique and "UNIQUE " or "" index_output.append("CREATE %sINDEX %s ON %s (%s);" % \ (unique, qn('%s_%s' % (tablename, f.name)), qn(tablename), qn(f.name))) table_output.append(" ".join(field_output)) full_statement = ["CREATE TABLE %s (" % qn(tablename)] for i, line in enumerate(table_output): full_statement.append(' %s%s' % (line, i < len(table_output)-1 and ',' or '')) full_statement.append(');') curs = connection.cursor() try: curs.execute("\n".join(full_statement)) except DatabaseError as e: transaction.rollback_unless_managed(using=db) raise CommandError( "Cache table '%s' could not be created.\nThe error was: %s." % (tablename, force_text(e))) for statement in index_output: curs.execute(statement) transaction.commit_unless_managed(using=db)