def reflect_table(engine, klass):
"""Inspect and reflect objects"""
try:
meta = MetaData()
meta.reflect(bind=engine)
except OperationalError as e:
raise DatabaseError(error=e.orig.args[1], code=e.orig.args[0])
# Try to reflect from any of the supported tables
table = None
for tb in klass.tables():
if tb in meta.tables:
table = meta.tables[tb]
break
if table is None:
raise DatabaseError(error="Invalid schema. Table not found",
code="-1")
# Map table schema into klass
mapper(klass, table,
column_prefix=klass.column_prefix())
return table
def close_database_session(session):
"""Close connection with the database"""
try:
session.close()
except OperationalError as e:
raise DatabaseError(error=e.orig.args[1], code=e.orig.args[0])
def create_database_session(engine):
"""Connect to the database"""
try:
Session = sessionmaker(bind=engine)
return Session()
except OperationalError as e:
raise DatabaseError(error=e.orig.args[1], code=e.orig.args[0])
def __init__(self, user, password, database, host='localhost', port='3306'):
self._engine = self.build_engine(user, password, database, host, port)
self._Session = sessionmaker(bind=self._engine)
try:
self.__create_schema(self._engine)
except OperationalError as e:
raise DatabaseError(error=e.orig.args[1], code=e.orig.args[0])
def execute(cls, engine, query):
try:
conn = engine.connect()
conn.execute(query)
except (OperationalError, ProgrammingError, InternalError) as e:
code = e.orig.args[0]
if isinstance(e, ProgrammingError) and code == 1007:
# Query for creating database failed because it exists
raise DatabaseExists(error=e.orig.args[1], code=code)
else:
raise DatabaseError(error=e.orig.args[1], code=code)
def test_message(self):
"""Make sure that prints the correct error"""
e = DatabaseError(error="Unknown database 'mydb'", code=1049)
self.assertEqual("Unknown database 'mydb' (err: 1049)", str(e))
def execute(cls, engine, query):
try:
conn = engine.connect()
conn.execute(query)
except (OperationalError, ProgrammingError) as e:
raise DatabaseError(error=e.orig.args[1], code=e.orig.args[0])
def build_engine(cls, user, password, database, host='localhost', port='3306'):
try:
return create_database_engine(user, password, database,
host, port)
except OperationalError as e:
raise DatabaseError(error=e.orig.args[1], code=e.orig.args[0])