I suggest you give a first stab at it and show us what you are doing. That would help us see your table relationships better (please use inner/outer joins to make it clearer) and get a better idea of what you are trying to do.
Also, providing data examples like some of the other posts really help
emp_table(
Cdacno varchar (7) (primary key),
Personal_No varchar (10)(foreign key),
Name varchar (40));
personal_table (
Personal_No varchar (10) (primary
key),
Cdacno varchar (7),
Date_Of_Birth date);
unit_master (
Unit id varchar (10) (primary key),
Unit_Name varchar(25),
