AnIntroductiontoDatabaseSystem学习目的重点难点AnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystem例子：创建一个学生信息表，其中输入性别字段值时，只能接受“F”或者“M”，并且为phonenum字段创建检查约束，限制只能输入类似80798654之类的数据，而不能随意输入其他数据。createtablestudent(Idchar(8),namechar(8),sexchar(2),phonenumint,constraintchk_sexcheck(sexin(’F’,’M’)),Constraintchk_phonenumcheck(phonenumlike‘[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]’))AnIntroductiontoDatabaseSystem补充AnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseSystemAnIntroductiontoDatabaseS