What steps can be taken to troubleshoot and resolve errors related to the mysql_num_rows() function in PHP when querying a database?

When encountering errors related to the mysql_num_rows() function in PHP when querying a database, it is important to ensure that the query is executed successfully and that the result set is valid. One common mistake is not checking if the query was executed properly before using mysql_num_rows(). To resolve this issue, you can check if the query was successful and then proceed to use mysql_num_rows() to get the number of rows returned by the query.

// Execute the query
$result = mysqli_query($connection, $query);

// Check if the query was successful
if($result) {
    // Get the number of rows returned by the query
    $num_rows = mysqli_num_rows($result);
    
    // Use the number of rows as needed
    echo "Number of rows: " . $num_rows;
} else {
    // Handle the error if the query was not successful
    echo "Error executing query: " . mysqli_error($connection);
}