The "IS" operator in SQLite works like the "IS NOT DISTINCT FROM" operator in PostgreSQL. Similarly the "IS NOT" operator in SQLite works like the "IS DISTINCT FROM" operator of PostgreSQL. <center> <table border="1" cellpadding="10"> <tr><th>SQLite<th>PostgreSQL <tr><td>IS<td>IS NOT DISTINCT FROM <tr><td>IS NOT<td>IS DISTINCT FROM </table></center>