要求按工作职能、时间、名称来查询，可是时间那块不好用，想查近两天的，结果时间不受限制，都能查出来，还有代码中“1＝1”是什么意思？
if ($HTTP_POST_VARS['jobfunction']==""){
$function="1=1" ;
}
else
{ $name1=$HTTP_POST_VARS['jobfunction'];
$function="j_invitation_function like '%$name1%'";
}

if ($HTTP_POST_VARS['issuedate']==""){
$issuedate="1" ;
}
else
{ $issuedate1=$HTTP_POST_VARS['issuedate'];
$issuedate="to_days(j_invitation_time) >= (to_days(now()) - $issuedate1)";

}

if ($HTTP_POST_VARS['jobdress']==""){
$dress="1=1" ;
}
else
{ $dress1=$HTTP_POST_VARS['jobdress'];
$dress="j_invitation_place like '%$dress1%'";
}

if ($HTTP_POST_VARS['name']==""){
$name="1=1" ;
}
else
{ $name1=$HTTP_POST_VARS['name'];
$name="j_company_name like '%$name1%'";
}
if ($HTTP_POST_VARS['position']==""){
$position="1=1" ;
}
else
{ $position1=$HTTP_POST_VARS['position'];
$position="j_invitation_position like '%$position1%'";
}



$sql="select * from j_invitation where $name and $function and $position and $dress and $issuedate order by j_invitation_time desc";


时间限制
近一天
近两天
近三天
近一周
近两周

提问者：zjzhouzg   06-02 15:03