What are two reasons to create synonym...

多项选择题What are two reasons to create synonyms? （）

A.You have too many tables.
B.Your tables are too long.
C.Your tables have difficult names.
D.You want to work on your own tables.
E.You want to use another schema's tables.
F.You have too many columns in your tables.

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1.单项选择题 Click the Exhibit button and examine the data from the ORDERS and CUSTOMERS tables.
Which SQL statement retrieves the order ID, customer ID, and order total for the orders that are placed on the same day that Martin placed his orders?（）

A.SELECT ord_id, cust_id, ord_total FROM orders, customers WHERE cust_name='Martin' AND ord_date IN ('18-JUL-2000','21-JUL-2000');
B.SELECT ord_id, cust_id, ord_total FROM orders WHERE ord_date IN (SELECT ord_date FROM orders WHERE cust_id = (SELECT cust_id FROM customers WHERE cust_name = 'Martin'));
C.SELECT ord_id, cust_id, ord_total FROM orders WHERE ord_date IN (SELECT ord_date FROM orders, customers WHERE cust_name = 'Martin');
D.SELECT ord_id, cust_id, ord_total FROM orders WHERE cust_id IN (SELECT cust_id FROM customers WHERE cust_name = 'Martin');

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2.多项选择题 Click the Exhibit button and examine the data from the EMP table.
The COMMISSION column shows the monthly commission earned by the employee.
Which two tasks would require subqueries or joins in order to be performed in a single step? （）

A.listing the employees who earn the same amount of commission as employee 3
B.finding the total commission earned by the employees in department 10
C.finding the number of employees who earn a commission that is higher than the average commission of the company
D.listing the departments whose average commission is more than 600
E.listing the employees who do not earn commission and who are working for department 20 in descending order of the employee ID
F.listing the employees whose annual commission is more than 6000

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3.单项选择题 Evaluate this SQL statement:
SELECT ename, sal, 12*sal+100 FROM emp;
The SAL column stores the monthly salary of the employee. Which change must be made to the above syntax to calculate the annual compensation as "monthly salary plus a monthly bonus of $100, multiplied by 12"?（）

A.No change is required to achieve the desired results.
B.SELECT ename, sal, 12*(sal+100) FROM emp;
C.SELECT ename, sal, (12*sal)+100 FROM emp;
D.SELECT ename, sal+100,*12 FROM emp;

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4.多项选择题Which three statements correctly describe the functions and use of constraints? （）

A.Constraints provide data independence.
B.Constraints make complex queries easy.
C.Constraints enforce rules at the view level.
D.Constraints enforce rules at the table level.
E.Constraints prevent the deletion of a table if there are dependencies.
F.Constraints prevent the deletion of an index if there are dependencies.

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5.单项选择题Evaluate the SQL statement:SELECT ROUND(TRUNC(MOD(1600,10),-1),2)FROM dual;What will be displayed?（）

A.0
B.1
C.0.00
D.an error statement

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6.单项选择题Which SQL statement displays the date March 19, 2001 in a format that appears as "Nineteenth of March 2001 12:00:00 AM"?（）

A.SELECT TO_CHAR(TO_DATE('19-Mar-2001', 'DD-Mon-YYYY'), 'fmDdspth "of" Month YYYY fmHH:MI:SS AM') NEW_DATE FROM dual;
B.SELECT TO_CHAR(TO_DATE('19-Mar-2001', 'DD-Mon-YYYY'), 'Ddspth "of" Month YYYY fmHH:MI:SS AM') NEW_DATE FROM dual;
C.SELECT TO_CHAR(TO_DATE('19-Mar-2001', 'DD-Mon-YYYY'), 'fmDdspth "of" Month YYYY HH:MI:SS AM') NEW_DATE FROM dual;
D.SELECT TO_CHAR(TO_DATE('19-Mar-2001', 'DD-Mon-YYYY'), 'fmtDdspth "of" Month YYYY fmtHH:MI:SS AM') NEW_DATE FROM dual;

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7.单项选择题In which scenario would an index be most useful?（）

A.The indexed column is declared as NOT NULL.
B.The indexed columns are used in the FROM clause.
C.The indexed columns are part of an expression.
D.The indexed column contains a wide range of values.

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8.单项选择题A subquery can be used to（）.

A.create groups of data
B.sort data in a specific order
C.convert data to a different format
D.retrieve data based on an unknown condition

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9.单项选择题 Click the Exhibit button to examine the data of the EMPLOYEES table. Evaluate this SQL statement:
SELECT e.employee_id "Emp_id", e.emp_name "Employee", e.salary, m.employee_id "Mgr_id", m.emp_name "Manager"
FROM employees e JOIN employees m ON (e.mgr_id = m.employee_id)
AND e.salary > 4000;
What is its output?（）

A.A
B.B
C.C
D.D
E.E

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10.多项选择题For which two actions can you use the TO_DATE function? （）

A.convert any date literal to a date
B.convert any numeric literal to a date
C.convert any date to a character literal
D.format 'January 10 1999' for input
E.format '10-JAN-99' to 'January 10 1999'

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