为什么我的查询产生错误“ORA-00933：SQL命令未正确结束”？

My query:

CREATE VIEW cambiodatos AS 
SELECT 
    a.last_name||','||a.first_name AS "Nombre", 
    a.salary AS "Salario", 
    b.name AS "Nombre Departamento", 
    c.name AS "Nombre de Region"
FROM 
    s_emp a, s_dept b, s_region c
WHERE 
    a.dept_id = b.id AND b.region_id = c.id

UPDATE 
     cambiodatos 
SET 
     name = 'North America'
WHERE 
     last_name = 'Biri'||','||first_name = 'Ben'
CREATE VIEW cambiodatos AS 
SELECT