在thinkphp的控制器中写sql语句的时候,哪种写法是正确的?
$result = $m->where('username="'.$user.'"')->find();
$result = $m->where('username='.$user)->find();
【代码A】
public function checkuser(){
$user = I('post.user');
$m = M('users');
$result = $m->where('username="'.$user.'"')->find();
$this->ajaxReturn($result);
}
【代码B】
public function checkuser(){
$user = I('post.user');
$m = M('users');
$result = $m->where('username='.$user)->find();
$this->ajaxReturn($result);
}