求教，关于oracle语句查询 or和and？

Question

oracle语句查询 or和and

Answer 1

(FirstName='Thomas' OR FirstName='William') AND LastName='Carter' 会得到 lastname 必须为 carter ，firstname 为 thomas 或者 william的人thomas carterwilliam carterFirstName='Thomas' OR FirstName='William' AND LastName='Carter' 可以得到 william carter 或者 firstname 为ithomas lastname 不一定是 carter的人 比如：thomas carterwilliam carterthomas king

Answer 2

与的优先级大于或不加等于SELECT * FROM Persons WHERE FirstName='Thomas' OR (FirstName='William'AND LastName='Carter')