title: SAWarning: Could not instantiate type <class 'sqlalchemy.sql.sqltypes.INTEGER'> when I use sqlalchemy and pd.io.sql.read_sql
body: <p>I try to read pandas DataFrame from my SQLite table. When I run the code below</p>
  
  <pre><code>import pandas as pd
  import sqlalchemy
  
  dbname = "sqlite:////Users/leda/home/Magnetic_stars/SQLite/Magnetic_stars.sqlite"
  engine = sqlalchemy.create_engine(dbname)
  res = pd.io.sql.read_sql("SELECT * FROM Resolved;", engine)
  </code></pre>
  
  <p>I get SAWarning:</p>
  
  <pre><code>/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sqlalchemy/dialects/sqlite/base.py:860: SAWarning: Could not instantiate type &lt;class 'sqlalchemy.sql.sqltypes.INTEGER'&gt; with reflected arguments [u'4']; using no arguments.
   coltype = self._resolve_type_affinity(type_)
  /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sqlalchemy/dialects/sqlite/base.py:860: SAWarning: Could not instantiate type &lt;class 'sqlalchemy.sql.sqltypes.INTEGER'&gt; with reflected arguments [u'2']; using no arguments.
   coltype = self._resolve_type_affinity(type_)
  </code></pre>
  
  <p>see my <a href="https://github.com/pydata/pandas/issues/7380" rel="nofollow">issue on github</a> for more details.</p>
  
  <p>What am I doing wrong? Is this a bug?</p>