Can I mix MySQL APIs in PHP?

Php Mysql Pdo Mysqli

The use of different MySQL APIs in PHP can sometimes be confusing, especially when it comes to connecting to the database and closing the connection properly. In this article, we will explore whether it is possible to mix mysql_ and mysqli_ APIs together in PHP and explain any issues that may arise.

Understanding the Difference between mysql_ and mysqli_

Before we dive into the issue at hand, let's first understand the difference between the mysql_ and mysqli_ APIs in PHP.

  • The mysql_ functions were the original set of functions used in PHP to interact with the MySQL database. These functions are procedural and have been deprecated as of PHP version 5.5.0.
  • The mysqli_ functions, on the other hand, are the improved version of the mysql_ functions. These functions are object-oriented and offer many enhancements over the original set of functions. The "i" in mysqli stands for "improved".

Using mysql_ and mysqli_ Together

Now that we have a basic understanding of the two APIs, let's address the main question: can we mix mysql_ and mysqli_ APIs together in PHP?

The short answer is yes, it is possible to use both mysql_ and mysqli_ APIs together in PHP. However, there are certain considerations and precautions that need to be taken into account.

Database Connection

To connect to the MySQL database using mysql_ functions, you would normally use the mysql_connect() function. Similarly, to connect using mysqli_ functions, you would use the mysqli_connect() function. In the provided code snippets, the connection is established correctly using both APIs.

<?php
$con=mysqli_connect("localhost", "root" ,"" ,"mysql");

if( mysqli_connect_errno( $con ) ) {
    echo "Failed to connect";
} else {
    echo "Connected";
}
mysql_close($con);
echo "Done";
?>
<?php
$con=mysql_connect("localhost", "root" ,"" ,"mysql");
if( mysqli_connect_errno( $con ) ) {
    echo "Failed to connect";
} else {
    echo "Connected";
}
mysqli_close($con);
echo "Done";
?>

However, when attempting to close the connection, we encounter a warning in both cases:

Warning: mysql_close() expects parameter 1 to be resource, object given in D:\************.php on line 9

This warning occurs because the mysql_close() function expects a resource as its parameter, which is the connection identifier returned by the mysql_connect() function. However, in the provided code snippets, we are passing the mysqli connection object instead of the resource.

Properly Closing the Connection

To properly close the connection using the respective API, we need to modify the code snippets as follows:

<?php
$con=mysqli_connect("localhost", "root" ,"" ,"mysql");

if (mysqli_connect_errno($con)) {
    echo "Failed to connect";
} else {
    echo "Connected";
}
mysqli_close($con);
echo "Done";
?>
<?php
$con=mysql_connect("localhost", "root" ,"" ,"mysql");
if (mysqli_connect_errno($con)) {
    echo "Failed to connect";
} else {
    echo "Connected";
}
mysql_close($con);
echo "Done";
?>

By using the mysqli_close() function in the first snippet and the mysql_close() function in the second snippet, we ensure that the connection is properly closed without any warnings.

Checking the Validity of the Connections

Now, let's address your question about checking the validity of the connections using the if statement.

In the provided code snippets, the if statement checks whether the connection has encountered any errors by using the function mysqli_connect_errno(). This function returns the last error code generated by the mysqli extension. If the code is zero, it means there are no errors.

if (mysqli_connect_errno($con)) {
    echo "Failed to connect";
} else {
    echo "Connected";
}

Similarly, if you want to check for errors using the mysql_ API, you can use the function mysql_errno().

if (mysql_errno($con)) {
    echo "Failed to connect";
} else {
    echo "Connected";
}

By using these error-checking functions, you can ensure that the connections are valid and handle any errors that may arise during the connection process.

Conclusion

In conclusion, it is possible to mix mysql_ and mysqli_ APIs together in PHP. However, it is important to be mindful of the differences between the two APIs and handle the database connections and closures appropriately. By using the error-checking functions, you can ensure that the connections are valid and handle any errors that may occur.

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