array( //a int field that cannot be null and acts as a unique identifier for all nid's 'nid' => array( 'type' => 'int', 'unsigned' => TRUE, 'not null' => TRUE, ), //a int field that cannot be null and is vid 'vid' => array( 'type' => 'int', 'not null' => TRUE, ), //a intfield, not null and project_id is the unique_id of the project in chado 'pub_id' => array( 'type' => 'int', 'unsigned' => TRUE, 'not null' => TRUE, ) ),//end of shema 'primary key' => array('nid','vid','pub_id'), ); return $schema; }