SqlAlchemy unable to map cratedb long and double data types.

I want to create new table in cratedb with one column of type long and other of type double using Sqlalchemy. I mapped long and double data types to Sqlalchemy's NUMERIC and DECIMAL data types as stated here. But they are not getting converted to long and double. Following is my code snippet.

     meta = MetaData(self.get_sqla_engine())
     Table('user', metadata,
         Column('id', Integer, primary_key=True),
         Column('user_name', String(), nullable=False),
         Column('num', DECIMAL(), nullable=False),
         Column('num2', NUMERIC(), nullable=False)
     )

     table = Table(datasource, meta, *columns)
     meta.create_all()

The sql query it creates is

     CREATE TABLE user (
             id INT, 
             user_name STRING,
             num DECIMAL,
             num2 NUMERIC, 
        PRIMARY KEY (id)
   );

As numeric and decimal are not supported cratedb types, cratedb throws error.

crate / sqlalchemy-cratedb

SqlAlchemy unable to map cratedb long and double data types. #124