Question

关于php mysql查询问题

其中$time1和$time2都是字符串（2015-05-06）类型的 ，riqi是数据库中的字段 也是字符串类型（2015-05-06），上面那段代码出问题了 应该怎么改，双引号怎么加
$sql="select *from think_kaoqin WHERE(1=1)"; if(!empty($uid)) { $sql .=" and uid= ".$uid; } if(!empty($time1) && empty($time2)) { $sql .=" and riqi >= ".$time1; } if (!empty($time2) &&empty($time1)) { $sql .=" and riqi <= ".$time2; } if (!empty($time1) && !empty($time2)) { $sql .=" and riqi >= ".$time1." and riqi <=".$time2; } $this->info=M('kaoqin')->query($sql);

Answer 1

if(!empty($uid))
{
$sql .=" and uid= ".$uid;
}
if(!empty($time1) && empty($time2))
{

$sql .=" and riqi >= '".$time1."'";
}
if (!empty($time2) &&empty($time1)) {

$sql .=" and riqi <= '".$time2."'";
}
if (!empty($time1) && !empty($time2)) {
$sql .=" and riqi >= '".$time1."' and riqi <='".$time2."'";
}

$this->info=M('kaoqin')->query($sql);