There may be a requirement where existing data in a MySQL table needs to be modified. You can do so by using SQL UPDATE command. This will modify any field value of any MySQL table.


Here is generic SQL syntax of UPDATE command to modify data into MySQL table:

UPDATE table_name SET field1=new-value1, field2=new-value2
[WHERE Clause]
  • You can update one or more field altogether.

  • You can specify any condition using WHERE clause.

  • You can update values in a single table at a time.

The WHERE clause is very useful when you want to update selected rows in a table.

Updating Data from Command Prompt:

This will use SQL UPDATE command with WHERE clause to update selected data into MySQL table tutorials_tbl.


Following example will update tutorial_title field for a record having tutorial_id as 3.

root@host# mysql -u root -p password;
Enter password:*******
mysql> use TUTORIALS;
Database changed
mysql> UPDATE tutorials_tbl 
    -> SET tutorial_title='Learning JAVA' 
    -> WHERE tutorial_id=3;
Query OK, 1 row affected (0.04 sec)
Rows matched: 1  Changed: 1  Warnings: 0


Updating Data Using PHP Script:

You can use SQL UPDATE command with or without WHERE CLAUSE into PHP function mysql_query(). This function will execute SQL command in similar way it is executed at mysql> prompt.


Try out the following example to update tutorial_title field for a record having tutorial_id as 3.

$dbhost = 'localhost:3036';
$dbuser = 'root';
$dbpass = 'rootpassword';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
if(! $conn )
  die('Could not connect: ' . mysql_error());
$sql = 'UPDATE tutorials_tbl
        SET tutorial_title="Learning JAVA"
        WHERE tutorial_id=3';

$retval = mysql_query( $sql, $conn );
if(! $retval )
  die('Could not update data: ' . mysql_error());
echo "Updated data successfully\n";