如何将Php对象转换为字符串？

我正在使用codeigniter从数据库中获取字符串，我想将数据库Postgres中的对象转换为字符串，我应该怎么做

public function gettable($username, $password){
    $cek_user = $this->db->query("SELECT hak_akses FROM tablelogin WHERE username = '$username' AND password = md5('$password')");  // Cek User Sudah Terdaftar
    if($cek_user->num_rows()>0){
        static $cek;
        foreach($cek_user->result() as $cek){
            $cek->hak_akses;
        }
        if($cek=='admin'){
            $ambil = $this->db->query("SELECT table_name FROM information_schema.tables WHERE table_schema='public' and table_name != 'tablelogin'");
            return $ambil->result();
        }
        if($cek=='semi_admin'){
            $ambil = $this->db->query("SELECT table_name FROM information_schema.tables WHERE table_schema='public' and table_name != 'tablelogin' and table_name != 'Film' and table_name != 'Hewan'");
            return $ambil->result();
        }
        if($cek == 'user'){
            $ambil = $this->db->query("SELECT table_name FROM information_schema.tables WHERE table_schema='public' and table_name != 'tablelogin' and table_name != 'Gudang' and table_name != 'inventaris' and table_name != 'Pegawai'");
            return $ambil->result();
        }
    }
    else {
        $hasil = null;
    }
} 

---

谢谢你的帮助。

我想你想比较一下

$cek->hak_-akses与
admin
或
semi\u admin
等一起使用。不需要转换为字符串。使用
row（）
结果集。并使用
else if
语句。如下

if($cek_user->num_rows()>0){

        $row = $cek_user->row();
        $cek =  $row ->hak_akses;

       if($cek=='admin'){
            $ambil = $this->db->query("SELECT table_name FROM information_schema.tables WHERE table_schema='public' and table_name != 'tablelogin'");
            return $ambil->result();
        }
       else if($cek=='semi_admin'){
            $ambil = $this->db->query("SELECT table_name FROM information_schema.tables WHERE table_schema='public' and table_name != 'tablelogin' and table_name != 'Film' and table_name != 'Hewan'");
            return $ambil->result();
        }
       else if($cek == 'user'){
            $ambil = $this->db->query("SELECT table_name FROM information_schema.tables WHERE table_schema='public' and table_name != 'tablelogin' and table_name != 'Gudang' and table_name != 'inventaris' and table_name != 'Pegawai'");
            return $ambil->result();
        }
    }
    else {
        $hasil = null;
    }