Question

I need a SQL Query to find Parent records without having any child records.Both child and parent records are on the same table

Answer 1

A SELF JOIN on the table as follows would give the parents without children.

-- relations (record_id, parent_id)
SELECT parents.record_id 
FROM 
    relations parents
    LEFT JOIN relations children
    ON parents.record_id = children.parent_id
WHERE 
    children.record_id IS NULL