fix dialect_name

Co-authored-by: Nicola Soranzo <[email protected]>

sqlalchemy_utils/functions/database.py

@@ -463,26 +463,27 @@ def sqlite_file_exists(database):
     url = copy(make_url(url))
     database, url.database = url.database, None
     engine = None
+    dialect_name = url.get_dialect().name
 
-    if engine.dialect.name.startswith('postgresql'):
+    if dialect_name == 'postgresql':
         ret = False
         for pdb in postgres_db:
             url.database = pdb
             engine = sa.create_engine(url)
             text = "SELECT 1 FROM pg_database WHERE datname='%s'" % database
             try:
                 ret = bool(get_scalar_result(engine, text))
-            except OperationalError:
+            except (ProgrammingError, OperationalError):
                 pass
             engine.dispose()
 
-    elif engine.dialect.name == 'mysql':
+    elif dialect_name == 'mysql':
         engine = sa.create_engine(url)
         text = ("SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA "
                 "WHERE SCHEMA_NAME = '%s'" % database)
         ret = bool(get_scalar_result(engine, text))
 
-    elif engine.dialect.name == 'sqlite':
+    elif dialect_name == 'sqlite':
         engine = sa.create_engine(url)
         if database:
             ret = database == ':memory:' or sqlite_file_exists(database)
@@ -501,7 +502,7 @@ def sqlite_file_exists(database):
 
         except (ProgrammingError, OperationalError):
             ret = False
-    
+
     if engine is not None:
         engine.dispose()
     return ret