with query1 do
begin
close;
sql.clear;
SQL.Add('select * from table where field1='''+Combobox.Text+''' and field2 between :aa and :bb');
parambyname('aa') .value:=值1;
parambyname('bb') .value:=值2;
prepare;
open;
end;
如果是ADO控件同理
SQL.Add('select * from table where field1='''+Combobox.Text+''' and field2 between :aa and :bb');
Open;
Parameters[0].Value:= aa // aa的值
Parameters[1].Value:= bb // bb的值