The EMPLOYEES table has these columns:...

单项选择题 The EMPLOYEES table has these columns:
LAST NAME VARCHAR2(35)
SALARY NUMBER(8,2)
HIRE_DATE DATE
Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement:
ALTER TABLE EMPLOYEES
MODIFY ( SALARY DEFAULT 5000);
What is true about your ALTER statement?（）

A. Column definitions cannot be altered to add DEFAULT values.
B. A change to the DEFAULT value affects only subsequent insertions to the table.
C. Column definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.
D. All the rows that have a NULL value for the SALARY column will be updated with the value 5000.

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1.单项选择题 Examine the data in the EMPLOYEES table.

On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. The JOB_ID column is a NOT NULL column.
Evaluate this DELETE statement:

Why does the DELETE statement fail when you execute it?（）

A. There is no row with dept_id 90 in the EMPLOYEES table.
B. You cannot delete the JOB_ID column because it is a NOT NULL column.
C. You cannot specify column names in the DELETE clause of the DELETE statement.
D. You cannot delete the EMPLOYEE_ID column because it is the primary key of the table.

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2.单项选择题Which substitution variable would you use if you want to reuse the variable without prompting the user each time?（）

A.&
B.ACCEPT
C.PROMPT
D.&&

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3.单项选择题What is true about the WITH GRANT OPTION clause?（）

A.It allows a grantee DBA privileges.
B.It is required syntax for object privileges.
C.It allows privileges on specified columns of tables.
D.It is used to grant an object privilege on a foreign key column.
E.It allows the grantee to grant object privileges to other users and roles.

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4.单项选择题 The EMP table has these columns:

Management wants a list of names of employees who have been with the company for more than five years. Which SQL statement displays the required results?（）

A. SELECT ENAME   FROM EMP   WHERE SYSDATE-HIRE_DATE > 5;
B. SELECT ENAME   FROM EMP   WHERE HIRE_DATE-SYSDATE > 5;
C. SELECT ENAME   FROM EMP   WHERE (SYSDATE-HIRE_DATE)/365 > 5;
D. SELECT ENAME   FROM EMP   WHERE (SYSDATE-HIRE_DATE)* 365 > 5;

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5.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

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6.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.

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7.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.

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8.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.

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9.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;

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10.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.

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