title: SQL Server pyodbc large text insertion issue
body: <p>I have a large string text to be inserted into a column in SQL Server 2014 Express (v12.0.2000). Initially I defined the field as <code>text</code> type and the data was inserted into the table without any issues. Later I found out that the <code>text</code> datatype is deprecated and not supposed to be used. Converting the datatype to <code>varchar(max)</code> started a weird issue in pyodbc. When the same data is inserted to the <code>varchar(max)</code> column, it throws an error with the following message:</p>
  
  <blockquote>
    <p>[HY000] [Microsoft][ODBC SQL Server Driver]Warning: Partial insert/update. The insert/update of a text or image column(s) did not succeed. (0) (SQLPutData)</p>
  </blockquote>
  
  <p>but the same insertion works fine with the <code>text</code> column.</p>
  
  <p>I was using <code>{SQL Server}</code> driver with windows authentication, when I changed it to <code>{SQL Server Native Client 11.0}</code> it started to fail in authentication, so I switched it back to <code>{SQL Server}</code> as it was working with the <code>text</code> data type.</p>
  
  <p>I looked into some of the discussion regarding similar issues, but could not find a case that helps in debugging the issue.</p>
  
  <p>I checked the sizes of strings where the data is successfully inserted and failed:</p>
  
  <ul>
  <li><code>TEXT</code>: all data inserted successfully.</li>
  <li><code>VARCHAR(MAX)</code>: string with length 98566 inserts but with length 326235 fails.</li>
  </ul>
  
  <p>Any guidance even debug tips will be highly appreciated. Thanks in advance.</p>