Php 我能'；t使用mysqli_query（）将记录插入我的表

我是PHP编程新手。所以我不明白为什么我的代码不能工作（并且没有显示任何错误） 我想将新记录插入我的表sinhvien 这是我的密码：

<?php
$con=new mysqli("localhost","root");
$con->select_db('learn_mysql');
$query="INSERT INTO sinhvien (ho,ten,tuoi) VALUES ('le','van cuong',26)";
$con->query($query);
$con->close();
?>

---

如果连接不正确，请尝试以下操作：

<?php
  $servername = "localhost";
  $username = "root";
  $password = "YOURS";
  $dbname = "learn_mysql";

  $conn = new mysqli($servername, $username, $password, $dbname);
  if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error());  exit(); }

  $sql = "INSERT INTO `sinhvien`(`ho`, `ten`, `tuoi`) VALUES ('le','van coung','26')";
  if ($conn->query($sql) === TRUE) {    } else {echo "Error: " . $sql . "<br>" . $conn->error;}

  $conn->close();
?>

我建议您阅读一些php mysqli基本教程。还可以尝试以面向对象的方式使用mysqli编写的语句
mysqli

下面是我的两个例子

0）使用MYSQLI连接到数据库

<?php
$localhost='localhost';
    $username='root';
    $password='admin';
    $databaseName='example';

    $con = new mysqli($localhost,$username,$password,$databaseName);

    if(mysqli_connect_errno()){
        die("connection Failed: ".mysqli_connect_errno());
    }

2） 使用MYSQLI准备语句的MYSQLI面向对象

//THIS IS ONE OF THE WAYS OF INSERTING DATA IN MYSQL USING MYSQLI PREPARED STATEMENT WHICH IS MORE SECURE AGAINST MYSQL INJECTION
$query=$con->stmt_init(); //INITIATE
$a='THIS IS';
$b='MYSQLI PREPARED STATEMENT';
$c=30;
if($query->prepare("INSERT INTO sinhvien(ho,ten,tuoi)VALUES(?,?,?)")){
    $query->bind_param('ssi',$a,$b,$c);//BIND THE ? TO THES VARIABLES
    $query->execute();//NOW EXECUTE THEM
    echo "INSERTED INTO THE DATABASE WITH MYSQLI PREPARED STATEMENT";
}

?>

您需要检查此项，请尝试检查->
如果（$con->connect\u error）回显$con->connect\u error
和->
$con->query（$query）或死亡（$con->error）这不是你连接的方式。请参见下面的答案。您需要指定password@Mihai根据文档-，密码是可选的。虽然不推荐，
//THIS IS ONE OF THE WAYS OF INSERTING DATA IN MYSQL USING MYSQLI PREPARED STATEMENT WHICH IS MORE SECURE AGAINST MYSQL INJECTION
$query=$con->stmt_init(); //INITIATE
$a='THIS IS';
$b='MYSQLI PREPARED STATEMENT';
$c=30;
if($query->prepare("INSERT INTO sinhvien(ho,ten,tuoi)VALUES(?,?,?)")){
    $query->bind_param('ssi',$a,$b,$c);//BIND THE ? TO THES VARIABLES
    $query->execute();//NOW EXECUTE THEM
    echo "INSERTED INTO THE DATABASE WITH MYSQLI PREPARED STATEMENT";
}

?>