SQL Query to sum and compare a field’s value based on relationship

Let the tables be,

Table: delivery_challan primary key: dcno	Table: invoice_entry Foreign key: dcno
dcno recqty 1 5 2 5	dcno desqty 1 2 1 3 2 3

Scenario: we have to sum the ‘desqty’ of the invoice_entry on ‘dcno’ wise and should compare with the ‘recqty’ of delivery_challan on ‘dcno’ wise and should show only the records of the ‘delivery_challan’ for which ‘recqty’ is greater than the sum of corresponding dcno’s ‘recqty’.

I am dam sure, you can’t understand my English. Just try the query and find the result.

SELECT * from delivery_challan where delivery_challan.recqty > (select sum(desqty) from invoice_entry where invoice_entry.dcno=delivery_challan.dcno);