php

PHP MySQL Update Data

The PHP update statement allows you to update existing records in the database’s table. The Update clause is mainly used in combination with the WHERE clause to perform modifications and updates to the records selectively.

In this guide, you will learn how to use the Update statement to perform modifications to a MySQL table.

The Basics

The update statement is straightforward and provides a simple and easy to use syntax, as shown below:

UPDATE tb_name SET col1=value, col2=value2,... WHERE col_name=value;

The statement takes the table on which to perform the modifications. Next, specify the columns and the values to update. You can also include the WHERE clause only to apply the changes in the columns that match a specified condition.

If you do not specify the WHERE clause, the changes will be applied in all the columns specified.

How to Use the Update Statement

Let us illustrate how to use the Update statement on a Database using PHP. We will do this by first defining an SQL query using the UPDATE statement. Finally, we will run the query using the mysqli_query() function.

Suppose we have a table containing simple information as shown below:

If we want to update the email of one of the customers in the database, we can use an example PHP code as shown below:

<?php
    $SERVERNAME = "localhost";
    $USERNAME = "root";
    $PASS = "mysql";
    $DB = "sakila";
    $conn = mysqli_connect($SERVERNAME, $USERNAME, $PASS, $DB);
    if ($conn->connect_error) {
        die("Connection to server failed: " . $conn->connect_error);
    }
    $query = "UPDATE customer SET email='[email protected]' WHERE customer_id=1";
    if ($conn->query($query) ==  TRUE) {
        echo "Specified Records updated...[OK]", "\n";
    }
    else {
        echo "Record Update Fail...[Error]", "\n";
    }
    $conn->close();
?>

The above code starts by creating a connection to the MySQL database using the specified credentials.

We then specify an UPDATE query to change the email of the customer with an id of 1.

Once we run the query, we should see an output indicating the records have been updated successfully.

php update_db.php
Specified Records updated...[OK]

To verify the changes have been made to the database, you can query the database as shown:

As you can see from the result, the value of the email column where the id=1 was changed.

Conclusion

This guide taught you how to update records in a database’s table using PHP and the update statement. Stay tuned for more tutorials.

About the author

John Otieno

My name is John and am a fellow geek like you. I am passionate about all things computers from Hardware, Operating systems to Programming. My dream is to share my knowledge with the world and help out fellow geeks. Follow my content by subscribing to LinuxHint mailing list