i have two tables
table1 has the folowing fields
lastprice
symbol
time
table2 has the same fields
now table1 stores only the last data of the corrosponding symbol
but table2 goeson adding the data as it comes in
now i want to write a query get the difference of the lastprice of table1 and the lastprice of table2 which was recorder 5 minutes back something like
table1.lastprice,table2.lastprice where
table2.time<(table2.time-5 min)
now the problem is that i have to get only the first data of table2 for the correspondig symbol for that time.
pls help