Query1.sql.add('select * from out where inputdate between :date1 and :date2');
query1.ParamByName('date1').AsString:='''1999-01-01''';
query1.ParamByName('date2').AsString:='''2002-01-01''';
query1.open;
query1.ParamByName('date1').AsString:='''1999-01-01''';
query1.ParamByName('date2').AsString:='''2002-01-01''';
query1.open;
begin
close;
sql.clear;
sql.add('select * from table where yourdate between :date1 and :date2');
parambyname('date1').asdatetime:=yourdate1;
parambyname('date2'),asdatetime:=yourdate2;
open;
end;