From Petr Sladek
SQL UPDATE SYNTAX
The overall syntax for SQL UPDATE SYNTAX is:
UPDATE table_name SET column_name=new_value WHERE id=value
So for example, if you want to update the value of the "started" field for the person with "id" equal to 123 in the table called "employee", you type:
UPDATE employee SET started=CURRENT WHERE id=123
In this example, you can see the DATE and DATE_TIME field setting to CURRENT.