Use bit type as said Borislav. VFP convert it ".t." or ".f." .

but if you want to use it directly a select command without use parameter you have to use 1 and 0 like that:

select * from mytable where my_bit_field=1 &&---- .t.

select * from mytable where my_bit_field=0 &&---- .f.

in vfp side you will see my_bit_field as a logical field.