MIS SQL 新进人员考式题目 A1_TEST.doc

姓名:郑文和 成績:_________________ Please Answer and explain the following question. True or False: If false ,please correct it. 1. select col1,col2 from t1 where col3=abc%; False,?把”=”改为like 2.Do the following statements return the same or different output. a. SELECT * FROM T1; b. select * from t1; same 3.The following queries do not work. Why not? a. Select *-- 未指明查询对象 b. Select * from t1 末尾未加分号 c. select col1 col2 col3 from t1;-- 各属性列要以逗号隔开 4.Will these query work? table:t1 column:col1 varchar2(10) a. select count(col1) from t1;-- yes b. select sum(col1) from t1; -- no,不能对varchar2型数据累加 5.Assume table t1 has column name,id table t2 has column name,id,salary Will the following SELECT statements work? select name,id,salary from t1,t2 where id = id and name like Smith%; no；select t1.name,t1.id,salsry from t1,t2 where t1.id=t2.id; select a.name,a.id,b.salary from t1 a,t2 b where name like Smith%; no；select a.name,a.id,b.salary from t1 a,t2 b where a.name like Smith%; select a.name,a.id,b.salary from t1 a,t2 b where a.id=b.id and a.name like Smith%; yes 6.Actual Data Defined as Store as 123456.789 number(6,2) 123456.79 false 123456.789 number(6) 123457 true 123456.789 number(6,-2) 123400 false,123500 123456.789 number 123456.789 true True or False? 2,Please explain the difference between the pair statements or explain 1.When a table is created ,who is the owner? 当前登陆的用户 2.Can you have duplicate table names in a database? yes 3.If data in a character column has varying length, what is the best choice for the data type? Varchar2 4.How can you find out what tables and views you own? select * from user_tables； select * from user_objects; 5.What are some database objects? 表视图存储过程函数触发器主键外