Which syntax turns an existing constra...

单项选择题Which syntax turns an existing constraint on? （）

A. ALTER TABLE table_name ENABLE constraint_name;
B. ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint _ name;
C. ALTER TABLE table_name ENABLE CONSTRAINT constraint _ name;
D. ALTER TABLE table_name TURN ON CONSTRAINT constraint _ name;

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1.单项选择题 Management has asked you to calculate the value 12*salary* commission_pct for all the employees in the EMP table. The EMP table contains these columns:
LAST NAME VARCNAR2(35) NOT NULL
SALARY NUMBER(9,2) NOT NULL
COMMISION_PCT NUMBER(4,2)
Which statement ensures that a value is displayed in the calculated columns for all employees? （）

A. SELECT last_name, 12*salary* commission_pct FROM emp;
B. SELECT last_name, 12*salary* (commission_pct,0) FROM emp;
C. SELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;
D. SELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;

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2.单项选择题 Examine the description of the EMPLOYEES table:
EMP_ID NUMBER(4) NOT NULL
LAST_NAME VARCHAR2(30) NOT NULL
FIRST_NAME VARCHAR2(30)
DEPT_ID NUMBER(2)
JOB_CAT VARCHARD2(30)
SALARY NUMBER(8,2)
Which statement shows the maximum salary paid in each job category of each department? （）

A. SELECT dept_id, job_cat, MAX(salary) FROM employees WHERE salary > MAX (salary);
B. SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id,job_cat;
C. SELECT dept_id, job_cat, MAX(salary) FROM employees;
D. SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id;
E. SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept _ id job _ cat salary;

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3.多项选择题Which two statements about views are true? （）

A. A view can be created as read only.
B. A view can be created as a join on two or more tables.
C. A view cannot have an ORDER BY clause in the SELECT statement.
D. A view cannot be created with a GROUP BY clause in the SELECT statement.
E. A view must have aliases defined for the column names in the SELECT statement.

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4.单项选择题The database administrator of your company created a public synonym called HR for the HUMAN_RESOURCES table of the GENERAL schema, because many users frequently use this table. As a user of the database, you created a table called HR in your schema. What happens when you execute this query? SELECT * FROM HR; （）

A. You obtain the results retrieved from the public synonym HR created by the database administrator.
B. You obtain the results retrieved from the HR table that belongs to your schema.
C. You get an error message because you cannot retrieve from a table that has the same name as a public synonym.
D. You obtain the results retrieved from both the public synonym HR and the HR table that belongs to your schema, as a Cartesian product.
E. You obtain the results retrieved from both the public synonym HR and the HR table that belongs to your schema, as a FULL JOIN.

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5.多项选择题 Examine the data in the EMPLOYEES table:

Which three subqueries work? （）

A. SELECT * FROM employees where salary > (SELECT MIN(salary) FROM employees GROUP BY department _ id);
B. SELECT * FROM employees WHERE salary = (SELECT AVG(salary) FROM employees GROUP BY department _ id);
C. SELECT distinct department_id FROM employees Where salary > ANY (SELECT AVG(salary) FROM employees GROUP BY department _ id);
D. SELECT department_id FROM employees WHERE SALARY > ALL (SELECT AVG(salary) FROM employees GROUP BY department _ id);
E. SELECT last_name FROM employees Where salary > ANY (SELECT MAX(salary) FROM employees GROUP BY department _ id);
F. SELECT department_id FROM employees WHERE salary > ALL (SELECT AVG(salary) FROM employees GROUP BY ANG (SALARY));

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6.单项选择题You need to give the MANAGER role the ability to select from, insert into, and modify existing rows in the STUDENT_GRADES table. Anyone given this MANAGER role should be able to pass those privileges on to others. Which statement accomplishes this? （）

A. GRANT select, insert, update ON student_grades TO manager
B. GRANT select, insert, update ON student_grades TO ROLE manager
C. GRANT select, insert, modify ON student_grades TO manager WITH GRANT OPTION;
D. GRANT select, insert, update ON student_grades TO manager WITH GRANT OPTION;
E. GRANT select, insert, update ON student_grades TO ROLE manager WITH GRANT OPTION;
F.GRANT select, insert, modify ON student_grades TO ROLE manager WITH GRANT OPTION;

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7.多项选择题 Examine the structure of the EMPLOYEES table:
EMPLOYEE_ID NUMBER Primary Key
FIRST_NAME VARCHAR2(25)
LAST_NAME VARCHAR2(25)
Which three statements inserts a row into the table? （）

A. INSERT INTO employees VALUES (NULL, 'JOHN','Smith');
B. INSERT INTO employees( first_name, last_name) VALUES ('JOHN','Smith');
C. INSERT INTO employees VALUES ('1000','JOHN','NULL');
D. INSERT INTO employees(first_name,last_name, employee_id) VALUES ('1000, 'john','Smith');
E. INSERT INTO employees (employee_id) VALUES (1000);
F. INSERT INTO employees (employee_id, first_name, last_name) VALUES ( 1000, 'john',");

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8.多项选择题Which two statements are true about WHERE and HAVING clauses? （）

A. A WHERE clause can be used to restrict both rows and groups.
B. A WHERE clause can be used to restrict rows only.
C. A HAVING clause can be used to restrict both rows and groups.
D. A HAVING clause can be used to restrict groups only.
E. A WHERE clause CANNOT be used in a query of the query uses a HAVING clause.
F. A HAVING clause CANNOT be used in subqueries.

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9.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.

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10.多项选择题 Examine the structure of the EMPLOYEES table:
EMPLOYEE_ID NUMBER Primary Key
FIRST_NAME VARCHAR2(25)
LAST_NAME VARCHAR2(25)
Which three statements inserts a row into the table? （）

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