title: Why there are 2 different ouputs
body: <pre><code>from sqlalchemy import Table, Column, Integer, String, MetaData, ForeignKey,create_engine
  engine = create_engine('sqlite:///college.db',echo = True)
  metadata = MetaData()
  users = Table('users', metadata,
        Column('id', Integer, primary_key=True),
        Column('name', String(50)),
        Column('fullname', String(50)),
  )
  
  addresses = Table('addresses', metadata,
     Column('id', Integer, primary_key=True),
     Column('user_id', None, ForeignKey('users.id')),
     Column('email_address', String(50), nullable=False))
  metadata.create_all(engine)
  </code></pre>
  
  <p>This is the first Output:</p>
  
  <pre><code>CREATE TABLE addresses (
  id INTEGER NOT NULL,
  user_id INTEGER,
  email_address VARCHAR NOT NULL,
  PRIMARY KEY (id),
  FOREIGN KEY(user_id) REFERENCES users (id)
  </code></pre>
  
  <p>Then, I hit run again, the output changed:</p>
  
  <pre><code>2019-04-18 21:06:57,881 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS VARCHAR(60)) AS anon_1
  2019-04-18 21:06:57,886 INFO sqlalchemy.engine.base.Engine ()
  2019-04-18 21:06:57,892 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS VARCHAR(60)) AS anon_1
  2019-04-18 21:06:57,899 INFO sqlalchemy.engine.base.Engine ()
  2019-04-18 21:06:57,904 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("users")
  2019-04-18 21:06:57,909 INFO sqlalchemy.engine.base.Engine ()
  2019-04-18 21:06:57,923 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("addresses")
  2019-04-18 21:06:57,928 INFO sqlalchemy.engine.base.Engine ()
  metadata.create_all(engine)
  2019-04-18 21:07:17,156 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("users")
  2019-04-18 21:07:17,157 INFO sqlalchemy.engine.base.Engine ()
  </code></pre>
  
  <p>Could annyone explain why there are some changes after i hit run the second time?</p>