Fetch_lengths

In this article, we will focus on the mysqli_fetch_lengths() function in PHP, which is used to fetch an array of the lengths of the columns in a result set. We will provide you with an overview of the function, how it works, and examples of its use.

Introduction to the mysqli_fetch_lengths() function

The mysqli_fetch_lengths() function is a built-in function in PHP that is used to fetch an array of the lengths of the columns in a MySQLi result set. This function is useful when you need to obtain the length of each column in a MySQLi query result set.

How to use the mysqli_fetch_lengths() function

Using the mysqli_fetch_lengths() function is very simple. You just need to call the function on a valid MySQLi result set after calling mysqli_fetch_row() or mysqli_fetch_all(). Here is an example:

<?php
$mysqli = mysqli_connect("localhost", "username", "password", "database");

$query = "SELECT * FROM my_table";
$result = mysqli_query($mysqli, $query);

if ($result) {
    while ($row = mysqli_fetch_row($result)) {
        $lengths = mysqli_fetch_lengths($result);
        for ($i = 0; $i < count($lengths); $i++) {
            printf("Length of column %d: %d\n", $i, $lengths[$i]);
        }
    }
}

mysqli_close($mysqli);
?>

In this example, we call the mysqli_connect() function to connect to a MySQL database with a username and password. We then execute a query using the mysqli_query() function to select all columns from a table. We store the result in a variable and check if there was a result using the $result variable. If there was a result, we use a while loop to iterate over each row in the result set. For each row, we call the mysqli_fetch_lengths() function to fetch an array of the lengths of each column in the result set. We then use a for loop to iterate over each element in the array and output the length of each column.

Conclusion

In conclusion, the mysqli_fetch_lengths() function is a useful tool for obtaining the length of each column in a MySQLi query result set. By understanding how to use the function, you can take advantage of this feature to create powerful and flexible MySQLi queries.