oracle语句查询 or和andSELECT * FROM Persons WHERE (FirstName='Thomas' OR FirstName='William')AND LastName='Carter'这个括号加和不加有什么区别,最后得出的数值是不同的.
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![oracle语句查询 or和andSELECT * FROM Persons WHERE (FirstName='Thomas' OR FirstName='William')AND LastName='Carter'这个括号加和不加有什么区别,最后得出的数值是不同的.](/uploads/image/z/15170175-63-5.jpg?t=oracle%E8%AF%AD%E5%8F%A5%E6%9F%A5%E8%AF%A2+or%E5%92%8CandSELECT+%2A+FROM+Persons+WHERE+%28FirstName%3D%27Thomas%27+OR+FirstName%3D%27William%27%29AND+LastName%3D%27Carter%27%E8%BF%99%E4%B8%AA%E6%8B%AC%E5%8F%B7%E5%8A%A0%E5%92%8C%E4%B8%8D%E5%8A%A0%E6%9C%89%E4%BB%80%E4%B9%88%E5%8C%BA%E5%88%AB%2C%E6%9C%80%E5%90%8E%E5%BE%97%E5%87%BA%E7%9A%84%E6%95%B0%E5%80%BC%E6%98%AF%E4%B8%8D%E5%90%8C%E7%9A%84.)
oracle语句查询 or和andSELECT * FROM Persons WHERE (FirstName='Thomas' OR FirstName='William')AND LastName='Carter'这个括号加和不加有什么区别,最后得出的数值是不同的.
oracle语句查询 or和and
SELECT * FROM Persons WHERE (FirstName='Thomas' OR FirstName='William')
AND LastName='Carter'
这个括号加和不加有什么区别,最后得出的数值是不同的.
oracle语句查询 or和andSELECT * FROM Persons WHERE (FirstName='Thomas' OR FirstName='William')AND LastName='Carter'这个括号加和不加有什么区别,最后得出的数值是不同的.
(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 carter
william carter
FirstName='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 carter
william carter
thomas king