examples of update statement in sql

Example 1: sql update with statement

UPDATE mytable t		-- Update using WITH statement
SET value3 = (
    WITH comp AS (
        SELECT id, value1
        FROM mytable t
        WHERE value2 > 10
    )
    SELECT c.value1
    FROM comp c
    WHERE c.id = t.id
);

Example 2: how to update values in sql

//to update value

UPDATE students SET course_id = 102
WHERE last_name = 'Jones'; -> 
                 if there is no condition it will update all!