title: MS Access: How does one insert NULL into DateTime field
body: <p>I have an MS Access database (intolerably enough), and communicating with it through PHP (ODBC).</p>
  
  <p>There is a DateTime field that I have to include in my INSERT statement. This field is NOT defined as "Required" in Access, meaning that it is indeed NULL-able, and in fact some of the rows in the Access database are already NULL.</p>
  
  <p>The problem I'm having is simple: How to insert NULL through SQL? All the results I've found online have addressed it from something like Visual Basic or C#, whereas I'm using SQL through ODBC in PHP.</p>
  
  <p>I have already tried the following:</p>
  
  <pre><code>INSERT INTO table_name (datetime_field) VALUES (NULL)
  INSERT INTO table_name (datetime_field) VALUES (#NULL#)
  INSERT INTO table_name (datetime_field) VALUES ('NULL')
  INSERT INTO table_name (datetime_field) VALUES ('#NULL#')
  INSERT INTO table_name (datetime_field) VALUES ('')
  </code></pre>
  
  <p>(There's about 30 other columns in my query.)</p>
  
  <p>The exact error I get is 'Data type mismatch in criteria expression' when I try '' or NULL. The others return a parse error (understandably).</p>
  
  <p>Please note that I have to include the field in the INSERT statement. The field has a default value, but in many cases the original data that I'm transporting has a NULL that must also be a NULL in the target database.</p>
  
  <p>Thanks in advance!</p>