title: R dbWriteTable More Than One Class Warning
body: <p>I've had a working R script that uses the dbWriteTable command to write to a SQL Server table. It has worked well without issue for a while ... until the last few days.</p>
  <p>Now when I run the dbWriteTable command, I get the following warning:</p>
  <pre><code>Found more than one class &quot;blob&quot; in cache; using the first, from namespace 'blob'
  Also defined by ‘jsonlite’
  </code></pre>
  <p>Interestingly enough the table appears to write successfully.</p>
  <p>Here is some sample code:</p>
  <pre><code>library(&quot;DBI&quot;)
  
  db_test &lt;- dbConnect(
    odbc(),
    driver = &quot;SQL Server&quot;,
    server = &quot;test_server&quot;,
    port = 1234,
    database = &quot;test_db&quot;
  )
  
  dbWriteTable(
    conn = db_test,
    name = SQL(&quot;dbo.swc_test_write_table&quot;),
    value = df_test,
    overwrite = TRUE
  )
  </code></pre>
  <p>I've tried explicitly naming the package, DBI::dbWriteTable, but it throws the same warning. For reference, I'm not using using the jsonlite package, but I have it installed.</p>
  <p>Any thoughts on why this is happening?</p>