Php SQL错误（错误：无法执行INSERT INTO）

我在phpmyAdmin上建立了一个数据库，它由三列组成：id、name和number。 我已经通过phpmyadmin向数据库添加了3行数据。 我现在希望通过我的php文件向这个数据库添加数据。这是我用来添加数据和在浏览器上显示数据的代码：

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

// Create connection
 $conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
} else {
echo "wooo connected";
}

$sql = "INSERT INTO hi (id, name, number)
VALUES ('99', 'Doe', '999999')";
if(mysqli_query($link, $sql)){
echo "Records inserted successfully.";
} else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}


//displaying data
$sql = "SELECT id, name, number FROM hi";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
    echo "id: " . $row["id"]. " - Name: " . $row["name"]. " " .                    $row["number"]. "<br>";
}
} else {
echo "0 results";
}

$conn->close();
?>

---

您在代码中引用的
$link
不存在，它应该是
$conn

改变这个：

if(mysqli_query($link, $sql)){
echo "Records inserted successfully.";
} else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}

至：

if(mysqli_query($conn, $sql)){
echo "Records inserted successfully.";
} else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}

您在代码中引用的
$link
不存在，它应该是
$conn

改变这个：

if(mysqli_query($link, $sql)){
echo "Records inserted successfully.";
} else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}

至：

if(mysqli_query($conn, $sql)){
echo "Records inserted successfully.";
} else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}

你需要修理这个

$conn = new mysqli($servername, $username, $password, $dbname);

到

这也需要解决

if(mysqli_query($conn, $sql)){
     echo "Records inserted successfully";
}else{
     echo "ERROR: Could not able to execute $sql. " . mysqli_error($conn);
}

你需要修理这个

$conn = new mysqli($servername, $username, $password, $dbname);

到

这也需要解决

if(mysqli_query($conn, $sql)){
     echo "Records inserted successfully";
}else{
     echo "ERROR: Could not able to execute $sql. " . mysqli_error($conn);
}

一个小小的解释有助于人们理解答案背后的原因。这个答案是非常错误的
new mysqli_connect
是完全错误的。一个小小的解释可以帮助人们理解答案背后的原因。这个答案是非常错误的<代码>新建mysqli_connect

完全错误。