i use such sentence to query access database in vb ,
it is ,
SELECT *
FROM table_1
WHERE (
((IIf(IsNull(value_1),'*' , field_1 Like '*' & value_1 & '*'))<>False) AND
'((IIf(IsNull(value_2),'*', field_2 Like '*' & value_2 & '*'))<>False) )
i imitate it in b4a , i make attempts time and again...