What are the two main types of stud link chain ________.
A.Oil Rig chain and Oil Field Stud Link chain
B.Flash-butt welded chain and Di-Lok chain
C.Flash-butt welded chain and Oil Rig chain
D.Oil Field Stud Link chain and Flash-butt welded chain
A.SELECT XM,SA FROM STUD FOR SA <25
B.SELECT XM,SA FROM STUD WHERE SA <25
C.SELECT XM,SA ON STUD FOR SA <25
D.SELECT XM,SA ON STUD WHERE SA <25
把学生表STUD中的学生“王小鱼”的姓名改为“王大川”,实现该功能的SQL语句是______。
A.UPDATE STUD姓名=“王小鱼”WHERE 姓名=“王大川”
B.UPDATE STUD姓名=“王大川”WHERE姓名=“王小鱼”
C.UPDATE STUD SET姓名=“王小鱼”WHERE姓名=“王大川”
D.UPDATE STUD SET姓名=“王大川”WHERE姓名=“王小鱼”
A、struct student { long no; double score; };
B、struct stud[20] { long no; double score; };
C、struct student { long no; double score; }stud[20];
D、struct { long no; double score; } stud[100];
A.SELECT * FROM stud ORDER BY birthday DESC LIMIT 8;
B.SELECT * FROM stud ORDER BY birthday ASC LIMIT 8;
C.SELECT * FROM stud ORDER BY birthday ASC LIMIT 7;
D.SELECT * FROM stud ORDER BY birthday DESC LIMIT 7;
删除学生表STUD中关于学号XH必须取唯一值的约束。实现该功能的正确SQL语句是______。
A.ALTER TABLE STUD ADD XH UNIQUE
B.ALTER TABLE STUD MODIFY XH UNIQUE
C.ALTER TABLE STUD DROP UNIQUE(XH)
D.ALTER TABLE STUD MODIFY UNIQUE(XH)
A.SHOW TABLE CREATE stud
B.DISPLAY CREATE TABLE stud
C.SHOW CREATE TABLE stud
D.DESCRIBE stud
将学生表STUD中的学生“王小鱼”的姓名改为“王大川”,实现该功能的SQL语句是______。
A.UPDATE STUD姓名="王小鱼"WHERE 姓名="王大川"
B.UPDATE STUD姓名="王大川"WHERE 姓名="王小鱼"
C.UPDATE STUD SET 姓名="王小鱼"WHERE姓名="王大川"
D.UPDATE STUD SET姓名="王大川"WHERE姓名="王小鱼"
删除学生表STUD中关于学号XH必须取惟一值的约束。实现该功能的正确SQL语句是 ______。
A.ALTER TABLE STUD ADD XH UNIQUE
B.ALTER TABLE STUD MODIFY XHUNIQUE
C.ALTER TABLE STUD DROP UNIQUE(XH)
D.ALTER TABLE STUD MODIFY UNIQUE(XH)
在学生表STUD中,查询年龄在20至23岁之间的学生的姓名(XM)、年龄(SA) 和所在系(SD) ,实现该功能的正确SQL语句是______。
A.SELECTXM,SA,SD FROM STUD WHERE BETWEEN 20
B.SELECT XM,SA,SD FROM STUD WHERE SA BETWEEN 23 AND 20;
C.SELECT XM,SA,SD FROM STUD WHERE SA NOT BETWEEN 20 AND 23;
D.SELECT XM,SA,SD FROM STUD WHERE SA BETWEEN 20 AND 23;
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