致命错误：未捕获的错误：调用未定义的函数mysql_connect()[duplicate]

Question

我是一个初学者，也是一个文凭学生...请帮我解决这个错误...我尝试了很多在线解决方案，但都无济于事...我是php和MySQL的新手...

<?php

$host="localhost"; // Host name 
$username="root"; // Mysql username 
$password=""; // Mysql password 
$db_name="slr"; // Database name 
$tbl_name="software"; // Table name 

// Connect to server and select database.
mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB");
// Get values from form 
$soft_name=$_POST['soft_name'];
$installed_date=$_POST['installed_date'];
$expiry_date=$_POST['expiry_date'];
$product_key=$_POST['product_key'];
// Insert data into mysql 
$sql="INSERT INTO $software(soft_name, installed_date, expiry_date, product_key)VALUES('$soft_name', '$installed_date', '$expiry_date', '$product_key')";
$result=mysql_query($sql);
// if successfully insert data into database, displays message "Successful". 
if($result){
    echo "Successful";
    echo "<BR>";
    echo "<a href='CreateData.php'>Back to main page</a>";
} else {
    echo "ERROR";
}
// close connection 
mysql_close();
?>

Answer 1

您应该使用mysql_connect而不是自PHP 5.5.0以来不推荐使用的mysql_connect:

    $link = mysqli_connect("$host", "$username", "$password")or die("cannot connect"); 
    mysqli_select_db($link, $db_name)or die("cannot select DB");