Automatically set to check if data is present in database

Hi I have a multiple checkboxes stored in one field in one of the tables (stored as array). I have to get all the array (which is working). What I wold like to ask is how can I automatically set the check box if the data is present in the database.

here's my code:

echo "&nbsp;<td><input id=\"services[]\" name=\"services[]\" type=\"checkbox\" value=\"$ser\"/>";
                                                      echo "<label for='services'>$ser</label><br>";
                                                      echo "</tr>";