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Question 1. Evaluate the SQL statement: TRUNCATE TABLE DEPT; Which three are true about the SQL statement? (Choose three.) A. It releases the storage space used by the table. B. It does not release the storage space used by the table. C. You can roll back the deletion of rows after the statement executes. D. You can NOT roll back the deletion of rows after the statement executes. E. An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error. F. You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table Answer: A, D, F Explanation: A: The TRUNCATE TABLE Statement releases storage space used by the table, D: Can not rollback the deletion of rows after the statement executes, F: You must be the owner of the table or have DELETE ANY TABLE system privilege to truncate the DEPT table. Incorrect answer: Cis not true Dis not true Eis not true Refer:Introduction toOracle9i:SQL, Oracle University Study Guide, 8-18 Question 2. You need to design a student registration database that contains several tables storing academic information. The STUDENTS table stores information about a student. The STUDENT_GRADES table stores information about the student's grades. Both of the tables have a column named STUDENT_ID. The STUDENT_ID column in the STUDENTS table is a primary key. You need to create a foreign key on the STUDENT_ID column of the STUDENT_GRADES table that points to the STUDENT_ID column of the STUDENTS table. Which statement creates the foreign key? A. CREATE TABLE student_grades (student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk REFERENCES (student_id) FOREIGN KEY students(student_id)); B. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id)); C. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT FOREIGN KEY (student_id) REFERENCES students(student_id)); D. CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id)); Answer: D Explanation: CONSTRAINT name FOREIGN KEY (column_name) REFERENCES table_name (column_name); Incorrect answer: Ainvalid syntax Binvalid syntax Cinvalid syntax Refer:Introduction toOracle9i:SQL, Oracle University Study Guide, 10-14 Question 3. Here is the structure and data of the CUST_TRANS table: Exhibit: Dates are stored in the default date format dd-mm-rr in the CUST_TRANS table. Which three SQL statements would execute successfully? (Choose three.) A. SELECT transdate + '10' FROM cust_trans; B. SELECT * FROM cust_trans WHERE transdate = '01-01-07'; C. SELECT transamt FROM cust_trans WHERE custno > '11'; D. SELECT * FROM cust_trans WHERE transdate='01-JANUARY-07'; E. SELECT custno + 'A' FROM cust_trans WHERE transamt > 2000; Answer: A, C, D Explanation: Question 4. See the Exhibit and examine the structure and data in the INVOICE table: Exhibit: Which two SQL statements would executes successfully? (Choose two.) A. SELECT MAX(inv_date),MIN(cust_id) FROM invoice; B. SELECT MAX(AVG(SYSDATE - inv_date)) FROM invoice; C. SELECT (AVG(inv_date) FROM invoice; D. SELECT AVG(inv_date - SYSDATE),AVG(inv)amt) FROM invoice; Answer: A, D Explanation: Question 5. Which three statements are true regarding sub queries? (Choose three.) A. Multiple columns or expressions can be compared between the main query and sub query B. Main query and sub query can get data from different tables C. Sub queries can contain GROUP BY and ORDER BY clauses D. Main query and sub query must get data from the same tables E. Sub queries can contain ORDER BY but not the GROUP BY clause F. Only one column or expression can be compared between the main query and subqeury Answer: A, B, C Explanation: Question 6. See the Exhibit and examine the structure of the CUSTOMERS table: Using the CUSTOMERS table, you need to generate a report that shown the average credit limit for customers in WASHINGTON and NEW YORK. Which SQL statement would produce the required result? A. SELECT cust_city, AVG(cust_credit_limit) FROM customers WHERE cust_city IN ('WASHINGTON','NEW YORK') GROUP BY cust_credit_limit, cust_city; B. SELECT cust_city, AVG(cust_credit_limit) FROM customers WHERE cust_city IN ('WASHINGTON','NEW YORK') GROUP BY cust_city,cust_credit_limit; C. SELECT cust_city, AVG(cust_credit_limit) FROM customers WHERE cust_city IN ('WASHINGTON','NEW YORK') GROUP BY cust_city; D. SELECT cust_city, AVG(NVL(cust_credit_limit,0)) FROM customers WHERE cust_city IN ('WASHINGTON','NEW YORK'); Answer: C Explanation: Creating Groups of Data: GROUP BY Clause Syntax You can use the GROUP BY clause to divide the rows in a table into groups. You can then use the group functions to return summary information for each group. In the syntax: group_by_expression Specifies the columns whose values determine the basis for grouping rows Guidelines • If you include a group function in a SELECT clause, you cannot select individual results as well, unless the individual column appears in the GROUP BY clause. You receive an error message if you fail to include the column list in the GROUP BY clause. • Using a WHERE clause, you can exclude rows before dividing them into groups. • You must include the columns in the GROUP BY clause. • You cannot use a column alias in the GROUP BY clause. Question 7. Evaluate these two SQL statements: SELECT last_name, salary, hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary, hire_date FROM EMPLOYEES ORDER BY 2 DESC; What is true about them? A. The two statements produce identical results. B. The second statement returns a syntax error. C. There is no need to specify DESC because the results are sorted in descending order by default. D. The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement. Answer: A Explanation: Explanation: the two statement produce identical results as ORDER BY 2 will take the second column as sorting column. Incorrect answer: Bthere is no syntax error Cresult are sorted in ascending order by default DORDER BY 2 will take the second column as sorting column. Refer: Introduction to Oracle9i: SQL, Oracle University Study Guide, 2-22 Question 8. Where can sub queries be used? (Choose all that apply) A. field names in the SELECT statement B. the FROM clause in the SELECT statement C. the HAVING clause in the SELECT statement D. the GROUP BY clause in the SELECT statement E. the WHERE clause in only the SELECT statement F. the WHERE clause in SELECT as well as all DML statements Answer: A, B, C, F Explanation: SUBQUERIES can be used in the SELECT list and in the FROM, WHERE, and HAVING clauses of a query. A subquery can have any of the usual clauses for selection and projection. The following are required clauses: A SELECT list A FROM clause The following are optional clauses: WHERE GROUP BY HAVING The subquery (or subqueries) within a statement must be executed before the parent query that calls it, in order that the results of the subquery can be passed to the parent. Question 9. Which three SQL statements would display the value 1890.55 as $1,890.55? (Choose three.) A. SELECT TO_CHAR(1890.55,'$99G999D00') FROM DUAL; B. SELECT TO_CHAR(1890.55,'$9,999V99') FROM DUAL; C. SELECT TO_CHAR(1890.55,'$0G000D00') FROM DUAL; D. SELECT TO_CHAR(1890.55,'$99G999D99') FROM DUAL; E. SELECT TO_CHAR(1890.55,'$9,999D99') FROM DUAL; Answer: A, C, D Explanation: Question 10. Evaluate the following SQL statement: Which statement is true regarding the outcome of the above query? A. It produces an error because the ORDER BY clause should appear only at the end of a compound query-that is, with the last SELECT statement B. It executes successfully and displays rows in the descending order of PROMO_CATEGORY C. It executes successfully but ignores the ORDER BY clause because it is not located at the end of the compound statement D. It produces an error because positional notation cannot be used in the ORDER BY clause with SET operators Answer: A Explanation: Using the ORDER BY Clause in Set Operations The ORDER BY clause can appear only once at the end of the compound query. Component queries cannot have individual ORDER BY clauses. The ORDER BY clause recognizes only the columns of the first SELECT query. By default, the first column of the first SELECT query is used to sort the output in an ascending order.
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