MySQL Num Rows - PHP

MySQL Num Rows is a PHP function that returns the number of rows in a MySQL result set. In this article, we will explore how to use this function in PHP, why it is important and what it can be used for.

Syntax

The syntax for the mysql_num_rows function is:

int mysql_num_rows (resource $result);

Where:

• result: Required. The result resource that is being evaluated.

Usage

To use the mysql_num_rows function, you first need to establish a connection to a MySQL database using the mysql_connect function. Once you have established a connection to the database, you can execute a MySQL query using the mysql_query function, which returns a result resource that can be used with the mysql_num_rows function.

Here is an example of how to use mysql_num_rows:

// Connect to the MySQL database
$link = mysql_connect('localhost', 'username', 'password', 'database');

// Execute a query and get the result resource
$result = mysql_query("SELECT * FROM users");

// Get the number of rows returned
$num_rows = mysql_num_rows($result);

echo "Number of rows: $num_rows";

Importance

The mysql_num_rows function is important because it allows you to determine the number of rows in a MySQL result set. This information is useful in many situations, such as:

• Checking if a query returned any results
• Determining the total number of results for pagination
• Displaying the number of search results found

Notes

• This function is deprecated in PHP 5.5.0 and removed in PHP 7.0.0.
• It is recommended to use the MySQLi or PDO_MySQL extension instead, as they offer improved security and performance features.

Conclusion

The mysql_num_rows function is an essential part of PHP programming when working with MySQL databases. It allows you to quickly and easily determine the number of rows in a MySQL result set, which is critical in many applications. However, it is important to note that this function is deprecated and should be replaced with the MySQLi or PDO_MySQL extension.