• 2022-05-28
    Certificate of Vessel’s Age
  • 船龄证明

    内容

    • 0

      学生表s有4个字段分别为:sno,sname,sex,age,要在表s中删除字段age,可选用的SQL语句是( )。 A: delete age from s; B: alter table s delete age; C: update s age; D: alter table s drop age;

    • 1

      若要删除基本表S中的Age列,应该选用的SQL语句是( )。 A: DELETE Age FROM S B: ALTER TABLE DROP Age C: UPDATE S Age D: ALTER TABLE S ‘Age’

    • 2

      45. A navigator fixing a vessel's position by radar ______.

    • 3

      He was impressed by the simplicity of the vessel's design. ( ) A: The simple design of the vessel left an impression of him. B: The simple design of the vessel left an impression on him. C: The simple design of the vessel leaves an impression with him. D: The simple design of the vessel leaves an impression upon him.

    • 4

      假定有学生关系S,结构为S(SID, SNAME, AGE),其中SID为学号,SNAME为姓名,AGE为年龄。查询所有比“李军”年龄大的学生的姓名、年龄,正确的SQL语句是( )。 A: SELECT SNAME, AGE FROM S WHERE AGE > ( SELECT AGE FROM S WHERE SNAME = '李军' ) B: SELECT SNAME, AGE FROM S WHERE AGE >( SNAME= '李军' ) C: SELECT SNAME, AGE FROM S WHERE AGE > ( SELECT AGE WHERE SNAME='李军' ) D: SELECT SNAME, AGE FROM S WHERE AGE>李军.AGE