Hi JAngle thanks for replying! I am new to this technology and I am not sure what actually needs to be done.
Let me give a detailed view of what I want:
I have 2 tables say Table1 and Table2, Table1 have 2 fields - code, desctiption and Table2 have3 fields - code, description, levels so I need to copy all data from table1 to table2 which is not already present in table2