在oracle中没有PK的连接更新表

UPDATE
  (
    SELECT
      a.COL1
    FROM
      TABLE1 a,
      TABLE2 b,
      TABLE3 c
    WHERE
      a.name = b.name
      c.ccol = b.ccol AND
      AND b.col1 = 'anyvalue'
      AND a.col2 = 'anothervalue'
  ) u
SET
  u.COL1 = 'VALUE'
UPDATE
  (
    SELECT
      a.COL1
    FROM