example data
lot table
id lotno cost
lot-1 BK-12 Php12,000
lot-2 BL-13 Php14,000
lot-3 BG-14 Php15,000
charges table
id name amount
1 Survey fee Php1000
2 Amortization Php2000
3 Monthly Dues Php3000
in my lot_charges form i have charges_id field ONLY
when i add charges to the lot all existing lot will get those charges. example result when i add amortization
result lot_charges table
id lot_id charges_id
1 lot-1 2
2 lot-2 2
3 lot-3 2