Let's use CommandBox to build it:
coldbox create orm-entity entityName=contacts primaryKey=contactID properties=firstName,lastName,email --open
Then spice it up with the validation constraints
/*** A cool Contact entity*/component persistent="true" table="contacts"{​// Primary Keyproperty name="contactID" fieldtype="id" column="contactID" generator="native" setter="false";​// Propertiesproperty name="firstName" ormtype="string";property name="lastName" ormtype="string";property name="email" ormtype="string";​// validationthis.constraints = {firstName = {required=true},lastName = {required=true},email = {required=true, type="email"}};​}