单项选择题Which constraint can be defines only at the column level?()

A.UNIQUE
B.NOT NULL
C.CHECK
D.PRIMARY KEY
E.FOREIGN KEY


您可能感兴趣的试卷

你可能感兴趣的试题

1.单项选择题In which scenario would TOP N analysis be the best solution?()

A. You want to identify the most senior employee in the company.
B. You want to find the manager supervising the largest number of employees.
C. You want to identify the person who makes the highest salary for all employees.
D. You want to rank the top three sales representatives who have sold the maximum number of products.

2.多项选择题Which three are true regarding the use of outer joins? ()

A. You cannot use IN operator in a condition that involves an outerjoin.
B. You use (+) on both sides of the WHERE condition to perform an outerjoin.
C. You use (*) on both sides of the WHERE condition to perform an outerjoin.
D. You use an outerjoin to see only the rows that do not meet the join condition.
E. In the WHERE condition, you use (+) following the name of the column in the table without matching rows, to perform an outerjoin.
F. You cannot link a condition that is involved in an outerjoin to another condition by using the OR operator.

3.单项选择题What is necessary for your query on an existing view to execute successfully?()

A. The underlying tables must have data.
B. You need SELECT privileges on the view.
C. The underlying tables must be in the same schema.
D. You need SELECT privileges only on the underlying tables.

4.单项选择题Which statement creates a new user?()

A. CREATIVE USER susan;
B. CREATIVE OR REPLACE USER susan;
C. CREATE NEW USER susan DEFAULT
D. CREATE USER susan IDENTIFIED BY blue;
E. CREATE NEW USER susan IDENTIFIED BY blue;
F. CREATE OR REPLACE USER susan IDENTIFIED BY blue;

5.多项选择题Which two statements accurately describe a role?()

A. A role can be given to a maximum of 1000 users.
B. A user can have access to a maximum of 10 roles.
C. A role can have a maximum of 100 privileges contained in it.
D. Privileges are given to a role by using the CREATE ROLE statement.
E. A role is a named group of related privileges that can be granted to the user.
F. A user can have access to several roles, and several users can be assigned the same role.

6.单项选择题You need to change the definition of an existing table. The COMMERCIALS table needs its DESCRIPTION column changed to hold varying length characters up to 2000 bytes. The column can currently hold 1000 bytes per value. The table contains 20000 rows.Which statement is valid?()

A. ALTER TABLE commercials MODIFY (description CHAR2(2000));
B. ALTER TABLE commercials CHANGE (description CHAR2(2000));
C. ALTER TABLE commercials CHANGE (description VARCHAR2 (2000));
D. ALTER TABLE commercials MODIFY (description VARCHAR2 (2000));
E. You cannot increase the size of a column if the table has rows.

7.单项选择题In which case would you use a FULL OUTER JOIN?()

A. Both tables have NULL values.
B. You want all unmatched data from one table.
C. You want all matched data from both tables.
D. You want all unmatched data from both tables.
E. One of the tables has more data than the other.
F. You want all matched and unmatched data from only one table.

9.单项选择题What does the TRUNCATE statement do?()

A. Removes the table
B. Removes all rows from a table
C. Shortens the table to 10 rows
D. Removes all columns from a table
E. Removes foreign keys from a table

10.单项选择题Which is an /SQL*Plus command?()

A. INSERT
B. UPDATE
C. SELECT
D. DESCRIBE
E. DELETE
F. RENAME

最新试题

Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary KeyFIRST_NAME VARCHAR2(25)LAST_NAME VARCHAR2(25)HIRE_DATE DATEWhich INSERT statement is valid? ()

题型:单项选择题

Examine the structure of the STUDENTS table:STUDENT_ID NUMBER NOT NULL, Primary KeySTUDENT_NAME VARCHAR2(30)COURSE_ID VARCHAR2(10) NOT NULLMARKS NUMBERSTART_DATE DATEFINISH_DATE DATEYou need to create a report of the 10 students who achieved the highest ranking in the course INT SQL and who completed the course in the year 1999.Which SQL statement accomplishes this task? ()

题型:单项选择题

Which three are true? ()

题型:多项选择题

Which four are types of functions available in SQL? ()

题型:多项选择题

Which statement correctly describes SQL and /SQL*Plus? ()

题型:单项选择题

Which statement accomplish this? ()

题型:单项选择题

You need to perform these tasks:1. Create and assign a MANAGER role to Blake and Clark2. Grant CREATE TABLE and CREATE VIEW privileges to Blake and ClarkWhich set of SQL statements achieves the desired results? ()

题型:单项选择题

A SELECT statement can be used to perform these three functions:1. Choose rows from a table.2. Choose columns from a table3. Bring together data that is stored in different tables by creating a link between them. Which set of keywords describes these capabilities? ()

题型:单项选择题

What is true regarding subqueries?()

题型:单项选择题

Which are /SQL*Plus commands? ()

题型:多项选择题