New mysqli php

Here is an example of how to use the mysqli extension in PHP to connect to a MySQL database and perform queries:

Connecting to the database

<?php
// Create a new mysqli object
$mysqli = new mysqli("localhost", "username", "password", "database");

// Check connection
if ($mysqli->connect_errno) {
    echo "Failed to connect to MySQL: (". $mysqli->connect_errno. ") ". $mysqli->connect_error;
    exit();
}
?>

In this example, we create a new mysqli object and pass in the following parameters:

localhost: the hostname or IP address of the MySQL server
username: the username to use for the connection
password: the password to use for the connection
database: the name of the database to connect to

We then check the connection using the connect_errno and connect_error properties of the mysqli object. If the connection fails, we display an error message and exit the script.

Performing a query

<?php
// Perform a query
$query = "SELECT * FROM users";
$result = $mysqli->query($query);

// Check if the query was successful
if (!$result) {
    echo "Query failed: (". $mysqli->errno. ") ". $mysqli->error;
    exit();
}

// Fetch the results
while ($row = $result->fetch_assoc()) {
    echo $row["username"]. "\n";
}

// Free the result set
$result->free();
?>

In this example, we perform a query using the query method of the mysqli object. We pass in the query string as a parameter.

We then check if the query was successful using the errno and error properties of the mysqli object. If the query failed, we display an error message and exit the script.

If the query was successful, we fetch the results using the fetch_assoc method of the mysqli_result object. We loop through the results and print out the values.

Finally, we free the result set using the free method of the mysqli_result object.

Closing the connection

<?php
// Close the connection
$mysqli->close();
?>

In this example, we close the connection using the close method of the mysqli object.

Error handling

The mysqli extension provides several ways to handle errors, including:

mysqli::connect_errno: returns the error number of the last connection attempt
mysqli::connect_error: returns the error message of the last connection attempt
mysqli::errno: returns the error number of the last query attempt
mysqli::error: returns the error message of the last query attempt

You can use these properties to check for errors and display error messages to the user.

Security considerations

When using the mysqli extension, it's important to take steps to secure your database connection and queries. Here are a few best practices to keep in mind:

Use prepared statements to prevent SQL injection attacks
Use parameterized queries to prevent SQL injection attacks
Use secure passwords and avoid hardcoding them in your code
Limit the privileges of the database user account used by your script
Use a secure connection (e.g. SSL/TLS) to encrypt data in transit

NewsBreakers

New mysqli php