title: RODBC sqlUpdate failed: Invalid character value for cast specification
body: <p><a href="https://i.stack.imgur.com/uR4I1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uR4I1.png" alt="enter image description here"></a></p>
  
  <p>Here is a screenshot of the console output after executing the sqlUpdate() function. As you can see, it fails at the first row of the data frame.</p>
  
  <p>I suspect that the problem has to do with the <code>introduced_at</code> list component of my <code>Bills.df</code> data frame.</p>
  
  <pre><code>Bills.df$introduced_at &lt;- as.Date(Bills.df$introduced_at, "%Y-%m-%d")
  </code></pre>
  
  <p>Before this statement, <code>introduced_at</code> is of type <code>character</code>. But this changes it to <code>double</code>. I understand that this may have something to do with the R internals, since it uses C data types to store various R data structures. Maybe it's the wrong expression for data type conversion?</p>
  
  <p>Additionally, if this is a <code>Date</code> type issue, I'd also like to know how to properly convert the <code>updated_at</code> type to Datetime to prevent a similar issue from occurring. The structure of <code>updated_at</code> is as follows: <code>2015-09-01T10:19:13-04:00</code>. I'm not comfortable with <code>as.POSIXlt</code> and <code>asPOSIXct</code> so I'm not sure which function is appropriate.</p>
  
  <pre><code>"updated_at": "2015-09-01T10:19:13-04:00"
  </code></pre>