无法识别的命令"只是UPDATE的拼写错误:

The "unrecognized command" is merely a misspelling of UPDATE:

UPDATAE B

// Should be
UPDATE B

要在执行UPDATE语句之前验证结果是否符合预期，请使用SELECT:

To verify the result is what you expect before executing the UPDATE statement, use a SELECT:

SELECT 
  to_char(substr(FIRST,1,4) || '-' || substr(FIRST, 6, 2) || '-' || substr(FIRST, 9, 2) || ' ' || substr(FIRST, 12, 8)) AS Test
FROM B