var sqlstr:string;
begin
sqlstr:='select * from "database.db" as aa where("aa.调查日期"<="'+datetostr(datetimepicker1.date)+'")and ("aa.调查日期">="'+datetostr(datetimepicker2.date)+'")';
query1.active:=false;
query1.sql.clear;
query1.sql.add(sqlstr);
query1.prepare;
query1.open ;
可以运行但是查不出任何结果
