didn't work but finally got it to work
This code is in my frmFares which has the custom column datagrid.
I changed the sql statement to
Select FareId,FareDate,FareHash,TimeStart,TimeEnd,Pickup,Dropoff,Fare,FareType, CASE(Booked) WHEN 1 THEN 'Yes' WHEN 0 THEN 'No' END As Booked From Fares...