Question

我有这个类可以在php中建立与MySQL数据库的连接。但它似乎有些问题，显然我犯了一个错误。

这是班级：

class dbConnection {

    public $CONN;

    public function __construct() {
        $dbservername = "localhost";
        $dbusername = "test";
        $dbpassword = "pass";
        $dbname = "dbtest";

        // Create connection
        $this->CONN = new mysqli($dbservername, $dbusername, $dbpassword, $dbname);

        // Check connection
        if ($this->CONN->connect_error) {
            die("Connection failed: " . $CONN->connect_error);
        }
        return $this->CONN;
    }

    public function close() {
        $this->CONN->close();
    }
}

这是要求班级执行INSERT：

$conn = new dbConnection();
$stmt = $conn->prepare("INSERT INTO tablename (stuff1, stuff2, stuff3) VALUES (?, ?, ?)");
$stmt->bind_param("sss", $val1, $val2, $val3);

// set parameters and execute
$val1 = "val1";
$val2 = "foo";
$val3 = "bar";
$stmt->execute();
$stmt->close();

显示的错误是：

Fatal error: Uncaught Error: Call to undefined method dbConnection::prepare() in /var/www/index.php:7 Stack trace: #0 {main} thrown in /var/www/index.php on line 7

如果我在类中设置一个函数并调用它而不是构造函数，这是有效的，但我想用构造函数本身完成它。我如何建立这个？

Answer 1

无法将自定义和系统函数应用于同一对象，因此您必须镜像自定义对象上的系统函数：

class connect{
public $CONN;
function __construct(){
$this->CONN=new mysqli();
}
function prepare($statement){
     $this->CONN->prepare($statement);
 }

Answer 2

您可以为public class SecondActivity extends Activity { private String name,email,phone,county; public void onCreate(Bundle bundle) { super.onCreate(bundle); setContentView(R.layout.main); //this is first activity data //you can get firstactivity data in second activity //and store data into varialbles name=getIntent().getStringExtra("name"); email=getIntent().getStringExtra("email"); phone=getIntent().getStringExtra("phone"); country=getIntent().getStringExtra("country"); } public void onResume() { super.onResume(); //put this code as per your requirement // i am just giving idea Intent i=new Intent(this,ThirdActivity.class); //this is first activity data put in intent i.putExtra("name",name); i.putExtra("email",email); i.putExtra("phone",phone); i.putExtra("country",country); //this is second activity data you also put on this intent i.putExtra("sex","male"); i.putExtra("age","24"); i.putExtra("city","jaipur"); startActivity(i); } }类创建public class FinalActivity extends Activity { private String name,email,phone,county,sex,age,city; public void onCreate(Bundle bundle) { super.onCreate(bundle); setContentView(R.layout.main); //this is first activity data and second activity data //you can get firstactivity and secondactivity data in Final activity //and store data into varialbles name=getIntent().getStringExtra("name"); email=getIntent().getStringExtra("email"); phone=getIntent().getStringExtra("phone"); country=getIntent().getStringExtra("country"); sex=getIntent().getStringExtra("sex"); age=getIntent().getStringExtra("age"); city=getIntent().getStringExtra("city"); //all data are in instance variable please use this data whenever } public void onResume() { super.onResume(); //if you need to send data another activity //please repeat again previous steps as per your requirement } }方法：

prepare

并且您当前的代码可以使用。在我的机器上测试它确实有效。

自定义数据库连接无法在php中工作

2 个答案: