PHP MySQL Update

In this tutorial you'll learn how to update the records in a MySQL table using PHP.

Updating Database Table Data
The [UPDATE](http://www.bixiaguangnian.com/manual/sql/3400.html "UPDATE") statement is used to change or modify the existing records in a database table. This statement is typically used in conjugation with the `WHERE` clause to apply the changes to only those records that matches specific criteria.

The basic syntax of the `UPDATE` statement can be given with:

```sql
UPDATE table_name SET column1=value, column2=value2,... WHERE column_name=some_value
```
Let's make a SQL query using the `UPDATE` statement and `WHERE` clause, after that we will execute this query through passing it to the PHP `mysqli_query()` function to update the tables records. Consider the following persons table inside the demo database:

```php
<?php
/* Attempt MySQL server connection. Assuming you are running MySQL
server with default setting (user 'root' with no password) */
$link = mysqli_connect("localhost", "root", "", "demo");
 
// Check connection
if($link === false){
    die("ERROR: Could not connect. " . mysqli_connect_error());
}
 
// Attempt update query execution
$sql = "UPDATE persons SET email='peterparker_new@mail.com' WHERE id=1";
if(mysqli_query($link, $sql)){
    echo "Records were updated successfully.";
} else {
    echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}
 
// Close connection
mysqli_close($link);
?>
```
After update the persons table will look something like this: