SELECT p.task_id, p.based_on, d.task_in_charge FROM proj_task_details p JOIN proj_task_details d ON (p.task_id = d.task_id);
SELECT p.task_id, p.based_on, d.task_in_charge FROM proj_task_details p FULL OUTER JOIN proj_task_details d ON (p.based_on = d.task_id);
SELECT p.task_id, p.based_on, d.task_in_charge FROM proj_task_details p JOIN proj_task_details d ON (p.based_on = d.task_id);
SELECT p.task_id, p.based_on, d.task_in_charge FROM proj_task_details p LEFT OUTER JOIN proj_task_details d ON (p.based_on = d.task_id);