SQL Database Quiz Questions

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  • 1/35 Questions

     Operator John needs to search for text data in a column, but he only remembers part of the string. Which of the following SQL operations allows the use of wildcard comparisons (choose one)?

    • BETWEEN
    • IN
    • LIKE
    • EXISTS
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  • 2. 

    Which SQL statement is used to return only different values?  

    • SELECT UNIQUE

    • SELECT DIFFERENT

    • SELECT DISTINCT

    • None of the above

    Correct Answer
    A. SELECT DISTINCT
    Explanation
    The SQL statement "SELECT DISTINCT" is used to return only different values. It eliminates duplicate rows from the result set and only displays unique values. This is useful when you want to retrieve distinct values from a column in a table.

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  • 3. 

    With SQL, how do you select all the records from a table named "Persons" where the "LastName" is alphabetically between (and including) "Hansen" and "Pettersen"?     

    • SELECT * FROM Persons WHERE LastName>'Hansen' AND LastName

    • SELECT * FROM Persons WHERE LastName BETWEEN 'Hansen' AND 'Pettersen'

    • SELECT LastName>'Hansen' AND LastName

    Correct Answer
    A. SELECT * FROM Persons WHERE LastName BETWEEN 'Hansen' AND 'Pettersen'
    Explanation
    The correct answer is "SELECT * FROM Persons WHERE LastName BETWEEN 'Hansen' AND 'Pettersen'". This query will select all the records from the table "Persons" where the "LastName" is alphabetically between (and including) "Hansen" and "Pettersen".

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  • 4. 

     The name of the only column in the DUAL table is  

    • X

    • C

    • DUMMY

    • None of these

    Correct Answer
    A. DUMMY
    Explanation
    The correct answer is DUMMY. The DUAL table is a special one-row, one-column table in Oracle database. It is often used for selecting a constant value or performing calculations. The only column in the DUAL table is named DUMMY.

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  • 5. 

    What will be the output select INSTR(‘HELLOWORLD’,’W’) from        dual; ?  

    • 5

    • 4

    • 6

    • 0

    Correct Answer
    A. 6
    Explanation
    The INSTR function in SQL is used to find the position of a substring within a string. In this case, the substring is 'W' and the string is 'HELLOWORLD'. The function will return the position of the first occurrence of the substring within the string. Since 'W' is the sixth character in 'HELLOWORLD', the output will be 6.

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  • 6. 

      The following SQL statement is illegal because: (choose one) SELECT deptno, AVG(sal) FROM emp WHERE AVG(sal)> 2000 GROUP BY deptno;

    • It requires data from more than one table, yet only one table is listed.

    • sal is not a legal column name

    • instead of a WHERE clause, a HAVING clause must be used to restrict groups

    • The GROUP BY clause must contain AVG(sal)

    • This SELECT statement is perfectly legal

    Correct Answer
    A. instead of a WHERE clause, a HAVING clause must be used to restrict groups
    Explanation
    The given SQL statement is illegal because it uses a WHERE clause to restrict groups instead of using a HAVING clause. In SQL, the WHERE clause is used to filter individual rows before they are grouped, while the HAVING clause is used to filter groups after they have been created. Since the statement is trying to restrict groups based on the average salary (AVG(sal)), it should use a HAVING clause instead of a WHERE clause.

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  • 7. 

    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?  

    • SELECT last_name, 12*salary* commission_pct FROM emp;

    • SELECT last_name, 12*salary* (commission_pct,0) FROM emp;

    • SELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;

    • SELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;

    Correct Answer
    A. SELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;
    Explanation
    The correct answer is SELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp; because the NVL function is used to substitute a null value with a specified value, in this case, 0. This ensures that even if the commission_pct column has null values, the calculation will still be performed and a value will be displayed in the calculated column for all employees.

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  • 8. 

    Examine the data from the ORDERS and CUSTOMERS table. ORDERS ORD_ID         ORD_DATE   CUST_ID       ORD_TOTAL 100                  12-JAN-2000              15                    180000 101                  09-MAR-2000                        40                    12500 102                  09-MAR-2000                        35                    12000 103                  15-MAR-2000                        15                    6000 104                  25-JUN-2000              15                    5000 105                  18-JUL-2000               20                    7000 106                  18-JUL-2000               35                    6500 107                  21-JUL-2000               20                    8000 108                  04-AUG-2000            10   CUSTOMERS CUST_ID       CUST_NAME                                    CITY 10                                Smith Los                    Angeles 15                                Bob                             San Francisco 20                                Martin                                     Chicago 25                                Mary                            New York 30                                Rina                             Chicago 35                                Smith                           New York 40                                Linda                           New York Which SQL statement retrieves the order ID, customer ID, and order total for the orders that are placed on the same day that Martin places his orders?  

    • SELECT ord_id, cust_id, ord_total FROM orders, customers WHERE cust_name=’Mating’ AND ord_date IN (’18-JUL-2000’,’21-JUL-2000’);

    • 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’));

    • SELECT ord_id, cust_id, ord_total FROM orders Where ord_date IN (SELECT ord_date FROM orders, customers Where cust_name = ‘Martin’);

    Correct Answer
    A. 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’));
    Explanation
    The correct answer is the second option. This SQL statement retrieves the order ID, customer ID, and order total for the orders that are placed on the same day that Martin places his orders. It uses subqueries to first find the customer ID of Martin and then find the order dates for that customer. The main query then selects the order ID, customer ID, and order total from the orders table where the order date is in the list of order dates for Martin.

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  • 9. 

    ) What operator would you choose to prevent this Oracle error message? (choose one) ORA-01427:single -row subquery returns more than one row

    • Use the IN operator

    • . Use the >= operator

    • Use the CAN EXIST operator

    • Use the = operator

    • Use the

    Correct Answer
    A. Use the IN operator
    Explanation
    The ORA-01427 error message occurs when a subquery returns more than one row, which is not allowed in certain situations. To prevent this error, the IN operator can be used. The IN operator allows for multiple values to be compared against a single value, ensuring that the subquery returns only one row. By using the IN operator, the query will be able to handle cases where the subquery returns multiple rows without causing the error.

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  • 10. 

     ) How many columns are presented after executing this query: SELECT address1||','||address2||','||address2 "Adress" FROM employee;  

    • 0

    • 1

    • 2

    • 3

    • 4

    Correct Answer
    A. 1
    Explanation
    The query is selecting three columns: address1, address2, and address2 (aliased as "Address"). The concatenation operator (||) is used to combine the values of address1, a comma, address2, a comma, and address2 again. However, since the alias "Address" is used for the third column, it appears as if there are only two distinct columns in the result. Therefore, the correct answer is 1.

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  • 11. 

    Which query is used to find maximum of the average salary of employees?

    • A) select avg(max(sal)) from emp;

    • B) select max(avg(sal)) from emp group by dept_id;

    • C) select maximum sal(avg) from emp;

    • D) none

    Correct Answer
    A. B) select max(avg(sal)) from emp group by dept_id;
    Explanation
    The correct answer is b) select max(avg(sal)) from emp group by dept_id. This query uses the MAX function to find the maximum value of the average salary of employees. It also uses the AVG function to calculate the average salary for each department by grouping the results using the GROUP BY clause.

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  • 12. 

    How would you display a listing of the sums of employee salaries for those employees not making a commission, for each job type, including only those sums greater than 2500? (choose one)

    • Select job, sum(sal) from emp where sum(sal) > 2500 and comm is null;

    • Select job, sum(sal) from emp where comm is null group by job having sum(sal) > 2500;

    • Select job, sum(sal) from emp where sum(sal) > 2500 and comm is null group by job;

    • Select job, sum(sal) from emp group by job having sum(sal) > 2500 and comm is not null;

    • None of the above

    Correct Answer
    A. Select job, sum(sal) from emp where comm is null group by job having sum(sal) > 2500;
    Explanation
    The correct answer is to select the job and the sum of salaries from the employee table, where the commission is null. Then, group the results by job and filter out only those sums that are greater than 2500. This query will display a listing of the sums of employee salaries for those employees not making a commission, for each job type, including only those sums greater than 2500.

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  • 13. 

    You query the database with this command: SELECT id_number, (quantity – 100 / 0.15 – 35 * 20) FROM inventory ; Which expression is evaluated first (choose one)?

    • Quantity – 100

    • 0.15-35

    • 35*20

    • 100/0.15

    Correct Answer
    A. 100/0.15
    Explanation
    The expression 100/0.15 is evaluated first because it is inside parentheses and according to the order of operations, expressions inside parentheses are evaluated first.

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  • 14. 

     What TRUNCATE and DELETE commands does?

    • To retrieve rows in a table

    • To remove some part of a table

    • To get rid of all rows in a table

    • To recover all the rows deleted in a table

    Correct Answer
    A. To get rid of all rows in a table
    Explanation
    The TRUNCATE and DELETE commands are used to remove data from a table. However, the key difference is that TRUNCATE removes all rows from a table, while DELETE allows for selective removal of specific rows based on specified conditions. Therefore, the correct answer is "To get rid of all rows in a table."

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  • 15. 

    With SQL, how do you select all the records from a table named "Persons" where the value of the column "FirstName" is "Peter"?   

    • SELECT [all] FROM Persons WHERE FirstName='Peter'

    • SELECT * FROM Persons WHERE FirstName='Peter'

    • SELECT * FROM Persons WHERE FirstName LIKE 'Peter'

    • SELECT [all] FROM Persons WHERE FirstName LIKE 'Peter'

    Correct Answer
    A. SELECT * FROM Persons WHERE FirstName='Peter'
    Explanation
    The correct answer is "SELECT * FROM Persons WHERE FirstName='Peter'". This query uses the SELECT statement to retrieve all columns (*) from the table "Persons" where the value of the column "FirstName" is "Peter".

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  • 16. 

    ) Evaluate the set of SQL statements: CREATE TABLE      dept     (deptno NUMBER(2), dname VARCNAR2(14), loc VARCNAR2(13)); ROLLBACK; DESCRIBE DEPT What is true about the set?  

    • The DESCRIBE DEPT statement displays the structure of the DEPT table.

    • The ROLLBACK statement frees the storage space occupies by the DEPT table.

    • The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist.

    • . The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.

    Correct Answer
    A. The DESCRIBE DEPT statement displays the structure of the DEPT table.
    Explanation
    The DESCRIBE DEPT statement is used to display the structure of the DEPT table. It provides information about the columns and their data types in the table.

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  • 17. 

    Which of the following queries would show the salaries of all employees (not the boss) who have the same name as the boss (the only employee without a manager (mgr)) (choose one)? 

    • Select sal from emp where ename same as (ename where mgr is NULL);

    • Select sal from emp where ename like (select ename from emp where mgr is NULL) and mgr is not NULL;

    • Select sal from emp where mgr != NULL and ename = (select ename from emp where mgr = NULL);

    • All of the above

    • None of the above

    Correct Answer
    A. Select sal from emp where ename like (select ename from emp where mgr is NULL) and mgr is not NULL;
    Explanation
    The correct answer is the second option: select sal from emp where ename like (select ename from emp where mgr is NULL) and mgr is not NULL. This query selects the salaries from the emp table where the employee name is the same as the boss (the only employee without a manager) and the manager is not NULL. This ensures that only employees who have the same name as the boss and are not the boss themselves are included in the result.

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  • 18. 

    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?  

    • SELECT dept_id, job_cat, MAX(salary) FROM employees WHERE salary > MAX(salary);

    • SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id, job_cat;

    • SELECT dept_id, job_cat, MAX(salary) FROM employees;

    • SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id;

    • SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id, job_cat, salary;

    Correct Answer
    A. SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id, job_cat;
    Explanation
    The correct answer is "SELECT dept_id, job_cat, MAX(salary) FROM employees GROUP BY dept_id, job_cat;". This statement uses the GROUP BY clause to group the data by department and job category. Then, it uses the MAX() function to find the maximum salary within each group. This will give the maximum salary paid in each job category of each department.

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  • 19. 

    Which Oracle access method is the fastest way for Oracle to retrieve a single row?

    • Primary key access

    • Access via unique index

    • Table access by ROWID

    • Full table scan

    Correct Answer
    A. Table access by ROWID
    Explanation
    Table access by ROWID is the fastest way for Oracle to retrieve a single row because it directly accesses the row using the unique identifier known as ROWID. This method does not require any additional lookups or index scans, making it the most efficient way to retrieve a specific row from a table. Primary key access and access via unique index also involve index lookups, while a full table scan reads all the rows in the table, making them slower compared to table access by ROWID.

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  • 20. 

    The EMPLOYEE tables has these columns: LAST_NAME VARCHAR2(35) SALARY NUMBER(8,2) COMMISSION_PCT NUMBER(5,2) You want to display the name and annual salary multiplied by the commission_pct for all employees. For records that have a NULL commission_pct, a zero must be displayed against the calculated column. Which SQL statement displays the desired results?  

    • SELECT last_name, (salary * 12) * commission_pct FROM EMPLOYEES;

    • SELECT last_name, (salary * 12) * IFNULL(commission_pct, 0) FROM EMPLOYEES;

    • SELECT last_name, (salary * 12) * NVL2(commission_pct, 0) FROM EMPLOYEES;

    • SELECT last_name, (salary * 12) * NVL(commission_pct, 0) FROM EMPLOYEES;

    Correct Answer
    A. SELECT last_name, (salary * 12) * NVL(commission_pct, 0) FROM EMPLOYEES;
    Explanation
    The correct answer is "SELECT last_name, (salary * 12) * NVL(commission_pct, 0) FROM EMPLOYEES;". This statement uses the NVL function to replace NULL values in the commission_pct column with 0. It then multiplies the annual salary (salary * 12) by the commission_pct to calculate the desired result.

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  • 21. 

    All of the following can ONLY be used with numeric datatypes except: (choose one) 

    • AVG

    • COUNT

    • SUM

    • STDDEV

    • VARIANCE

    Correct Answer
    A. COUNT
    Explanation
    COUNT is the only function among the options that can be used with both numeric and non-numeric datatypes. It counts the number of rows in a table or the number of occurrences of a specific value. AVG, SUM, STDDEV, and VARIANCE are all functions that specifically operate on numeric datatypes and perform mathematical calculations.

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  • 22. 

    Which of the following query  display the last name,hire date and the day of the week on which the employee started with column label as DAY and ordered by the day of the week starting with Monday.

    • SELECT last_name, hire_date, TO_CHAR(hire_date,'DAY') AS DAY FROM employees ORDER BY hire_date, DAY;

    • . SELECT last_name, hire_date, TO_CHAR(hire_date,'DD') AS DAY FROM employees ORDER BY hire_date, DAY;

    • SELECT last_name, hire_date, TO_CHAR(hire_date,'DY') AS DAY FROM employees ORDER BY hire_date, DAY;

    • All the above.

    Correct Answer
    A. SELECT last_name, hire_date, TO_CHAR(hire_date,'DAY') AS DAY FROM employees ORDER BY hire_date, DAY;
    Explanation
    The correct answer is the first option: SELECT last_name, hire_date, TO_CHAR(hire_date,'DAY') AS DAY
    FROM employees
    ORDER BY hire_date, DAY;

    This query selects the last name, hire date, and the day of the week on which the employee started. The TO_CHAR function is used to convert the hire date to the day of the week format. The column label for the day of the week is set as "DAY". The result is ordered by the hire date and the day of the week, starting with Monday.

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  • 23. 

    Which clause should you use to exclude GROUP results ?  

    • WHERE

    • RESTRICT

    • HAVING

    • GROUP BY

    Correct Answer
    A. HAVING
    Explanation
    The HAVING clause is used to exclude GROUP results in a SQL query. It is typically used in combination with the GROUP BY clause to filter the results based on conditions that are applied to the grouped data. This allows you to specify criteria for the groups that should be included or excluded in the final result set. The HAVING clause is different from the WHERE clause, which is used to filter individual rows before they are grouped.

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  • 24. 

    Substitution variable can be used with which of the following clauses?

    • Select

    • From

    • Where

    • Group by

    • All the above

    Correct Answer
    A. All the above
    Explanation
    Substitution variables can be used with all of the mentioned clauses (Select, From, Where, Group by). Substitution variables are placeholders that can be used to dynamically substitute values in a SQL statement. They are commonly used to make the SQL statement more flexible and reusable by allowing users to input different values at runtime. By using substitution variables, the same SQL statement can be executed with different values without the need to modify the statement itself.

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  • 25. 

    What output will the follwing statement produce? Select NVL2(NULL,'NOT NULL', NULL) from dual;  

    • NULL

    • NOT NULL

    • Function NVL2 is not defined

    • None of the above

    Correct Answer
    A. NULL
    Explanation
    The NVL2 function in Oracle is used to determine the value to be returned based on the condition. In this case, the condition is NULL. If the condition is true, the second argument ('NOT NULL') is returned. If the condition is false or NULL, the third argument (NULL) is returned. Since the condition is NULL, the third argument is returned, resulting in the output of NULL.

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  • 26. 

    What will be the output ? SELECT ROUND(TRUNC(MOD(1600,10),-1),2) from dual;  

    • Error

    • 0

    • 1

    • 0.00

    Correct Answer
    A. 0
    Explanation
    The given SQL statement calculates the modulus of 1600 divided by 10, which results in 0. The TRUNC function is then used to truncate this value to the nearest multiple of 10, which is also 0. Finally, the ROUND function is applied to round this value to 2 decimal places, which is still 0. Therefore, the output of the statement will be 0.

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  • 27. 

    Which of the following statements are true (choose two)?

    • 'NOT IN' is equivalent to != ALL

    • 'IN' is equivalent to != ALL

    • 'NOT IN' is equivalent to =ANY

    • 'IN' is equivalent to =ANY

    • None of the above are true

    Correct Answer(s)
    A. 'NOT IN' is equivalent to != ALL
    A. 'IN' is equivalent to =ANY
    Explanation
    'NOT IN' is equivalent to != ALL means that when using the 'NOT IN' operator, it checks if a value is not present in a set of values, similar to using the != (not equal to) operator with the ALL keyword.

    'IN' is equivalent to =ANY means that when using the 'IN' operator, it checks if a value is present in a set of values, similar to using the = (equal to) operator with the ANY keyword.

    Both statements explain the equivalence between these operators and their corresponding combinations with the != and = operators.

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  • 28. 

    Which of the following can be a valid column name? 

    • Column

    • 1966_Invoices

    • Catch_#22

    • #Invoices

    • None of the above

    Correct Answer
    A. Catch_#22
    Explanation
    column name should start with a alphabet and it cannot start with no: or special char

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  • 29. 

    Which SELECT statement will return a numeric value?

    • SELECT SYSDATE - enroll_date + TO_DATE('29-MAY-02') FROM student;

    • SELECT (14 + enroll_date) + 30.5 * 9 FROM student;

    • SELECT (SYSDATE+ enroll_date) + TO_DATE('29-MAY-02') FROM student;

    • SELECT (SYSDATE - enroll_date) + 30.5 * 9 FROM student;

    Correct Answer
    A. SELECT (SYSDATE - enroll_date) + 30.5 * 9 FROM student;
    Explanation
    The SELECT statement that will return a numeric value is the fourth option: SELECT (SYSDATE - enroll_date) + 30.5 * 9 FROM student. This is because it performs mathematical operations (subtraction, multiplication, and addition) on the values SYSDATE, enroll_date, and 30.5, which are all numeric values. The result of these operations will also be a numeric value.

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  • 30. 

     ) Assuming today is Monday, 10 July 2000, what is returned by this statement: SELECT to_char(NEXT_DAY(sysdate, 'MONDAY'), 'DD-MON-RR') FROM dual;  

    • 03-JUL-00

    • 10-JUL-00

    • 12-JUL-00

    • 11-JUL-00

    • 17-JUL-00

    • 09-JUL-00

    Correct Answer
    A. 17-JUL-00
    Explanation
    The statement returns the date of the next Monday from the current date. Since today is Monday, 10 July 2000, the next Monday after this date is 17 July 2000. Therefore, the statement will return "17-JUL-00".

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  • 31. 

    Examine the description of the STUDENTS table: STD_ID          NUMBER(4) COURSE_ID             VARCHARD2(10) START_DATE DATE END_DATE   DATE Which two aggregate functions are valid on the START_DATE column? (Choose two)  

    • SUM(start_date)

    • AVG(start_date)

    • COUNT(start_date)

    • AVG(start_date, end_date)

    • MIN(start_date)

    • MAXIMUM(start_date)

    Correct Answer(s)
    A. COUNT(start_date)
    A. MIN(start_date)
    Explanation
    The COUNT(start_date) function is valid on the START_DATE column because it counts the number of non-null values in the column. The MIN(start_date) function is also valid on the START_DATE column because it returns the minimum value in the column.

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  • 32. 

    Given the following data in the emp table: ENAME SALARY -------- -------- PING 5000 AILYN 4999 SAM 1000 LESLIE 3000 TOM 2500 RAVI 10000 What will the following select statement produce (choose one)? SELECT ename FROM emp WHERE salary BETWEEN 3000 AND 5000;

    • ENAME -------- AILYN

    • . ENAME -------- . AILYN CHRIS LESLIE

    • An error

    • None of the above

    Correct Answer
    A. None of the above
    Explanation
    The select statement will produce the following result: ENAME
    --------
    AILYN
    CHRIS
    LESLIE
    This is because the select statement is filtering the data from the emp table based on the condition WHERE salary BETWEEN 3000 AND 5000, which means it will select all the rows where the salary is between 3000 and 5000, inclusive. In this case, the rows with the names AILYN, CHRIS, and LESLIE have salaries within this range, so they will be included in the result. Therefore, the correct answer is "None of the above" as it is not one of the given options.

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  • 33. 

     SELECT ROUND (45.953, -1), TRUNC (45.936, 2) FROM dual; Which values are displayed?  

    • 46 and 45

    • 46 and 45.93

    • 50 and 45.93

    • 50 and 45.9

    • 45 and 45.93

    • 45.95 and 45.93

    Correct Answer
    A. 50 and 45.93
    Explanation
    The ROUND function rounds the first number, 45.953, to the nearest multiple of 10, resulting in 50. The TRUNC function truncates the second number, 45.936, to two decimal places, resulting in 45.93. Therefore, the values displayed are 50 and 45.93.

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  • 34. 

    Examine the structure of the employees table. Employee_id number primary key First_name varchar2(25) Last_name varchar2(25) Which 3 statements inserts a row into the table employees?  

    • 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’’Smith’);

    • 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’,’’);

    Correct Answer(s)
    A. C. INSERT INTO employees VALUES(1000,’John’’Smith’);
    A. E. INSERT INTO employees (employee_id) VALUES(1000);
    A. F. INSERT INTO employees (employee_id,first_name,last_name) VALUES(1000’John’,’’);
    Explanation
    The correct answers are C, E, and F.

    C. INSERT INTO employees VALUES(1000,’John’’Smith’); - This statement inserts a row into the employees table with the specified values for employee_id, first_name, and last_name.

    E. INSERT INTO employees (employee_id) VALUES(1000); - This statement inserts a row into the employees table with only the employee_id specified.

    F. INSERT INTO employees (employee_id,first_name,last_name) VALUES(1000’John’,’’); - This statement inserts a row into the employees table with the specified values for employee_id, first_name, and last_name. However, there is a syntax error in the statement as there is a missing comma between 1000 and 'John'.

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  • 35. 

    Which of the following are legal queries? (choose one or more)

    • SELECT deptno, count(deptno) FROM emp GROUP BY ename;

    • SELECT deptno, count(deptno), job FROM emp GROUP BY deptno;

    • SELECT deptno, avg(sal) FROM emp;

    • SELECT deptno, avg(sal) FROM emp GROUP BY deptno;

    • SELECT avg(sal) FROM emp GROUP BY deptno;

    Correct Answer(s)
    A. SELECT deptno, avg(sal) FROM emp GROUP BY deptno;
    A. SELECT avg(sal) FROM emp GROUP BY deptno;
    Explanation
    The correct answer includes two queries: "SELECT deptno, avg(sal) FROM emp GROUP BY deptno;" and "SELECT avg(sal) FROM emp GROUP BY deptno;". These queries are legal because they both use the "avg" function to calculate the average salary and group the results by the department number. This is a valid use of the "GROUP BY" clause in SQL.

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Quiz Review Timeline (Updated): Mar 22, 2023 +

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  • Current Version
  • Mar 22, 2023
    Quiz Edited by
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  • Dec 01, 2011
    Quiz Created by
    Kavmuni
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