Databases - Upwork

Question: Examine the two SQL statements given below: 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 while first will be executed successfully

C
The second statement will return top 2 records having maximum salary, while first statement will return all records

D
There is no need to specify DESC because the results are sorted in descending order by default

Note: Not available
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Question: What will happen if you query the emp table shown below: select empno,DISTINCT ename,Salary from emp;
A
EMPNO ,unique value of ENAME and then SALARY are Displayed.

B
EMPNO ,unique value of the two columns, ENAME and salary are displayed.

C
DISTINCT is not a valid keyword in SQL.

D
No values will be displayed because the statement will return an error

Note: Not available
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Question: How many join conditions should be there to avoid a Cartesion Join for joining three tables?
A
1

B
2

C
3

D
None of these

Note: Not available
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Question: Which operator will be evaluated first in the statement: select (2+3*4/2-8) from dual:
A
+

B
-

C
/

D
*

Note: Not available
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Question: Which of the following SQL statements returns a numeric value?
A
SELECT ADD_MONTHS(MAX (hire_date), 6) FROM EMP;

B
SELECT ROUND(hire_date)FROM EMP;

C
SELECT sysdate-hire_date FROM EMP;

D
SELECT TO_NUMBER(hire_date + 7)FROM EMP;

Note: Not available
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Question: Which of the following SELECT statements will get the result 'elloworld' from the string 'HelloWorld'?
A
SELECT SUBSTR ('HelloWorld',1) FROM dual;

B
SELECT INITCAP(TRIM('HellowWorld', 1,1) FROM dual;

C
SELECT LOWER (SUBSTR ('HellowWorld', 2,1) FROM dual;

D
SELECT LOWER (TRIM ('H' FROM 'HelloWorld')) FROM dual;

Note: Not available
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Question: You want to list names of the employees who have been with the company for more than five years. Which of the following SQL statements will display 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

Note: Not available
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Question: Examine the structure of the STUDENTS table given below: STUDENT_ID �NUMBER �NOT NULL, Primary Key STUDENT_NAME VARCHAR2 (30) COURSE_ID VARCHAR2 (10) NOT NULL MARKS NUMBER START_DATE DATE FINISH_DATE DATE You need to create a report of ten students who achieved the highest ranking in the course INT_SQL and completed the course in the year 1999. Which of the following SQL statements accomplishes this task?
A
SELECT student_id, marks, ROWNUM "Rank" FROM students WHERE ROWNUM <= 10 AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99' AND course_id = 'INT_SQL'ORDER BY marks DESC;

B
SELECT student_id, marks, ROWID "Rank" FROM students WHERE ROWID <= 10 AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99'AND course_id = 'INT_SQL'ORDER BY marks;

C
SELECT student_id, marks, ROWNUM "Rank" FROM (SELECT student_id, marks FROM students WHERE ROWNUM <= 10 AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99' AND course_id = 'INT_SQL' ORDER BY marks DESC);

D
SELECT student_id, marks, ROWNUM "Rank" FROM (SELECT student_id, marks FROM students WHERE finish_date BETWEEN '01-JAN-99' AND '31-DEC-99' AND course_id = 'INT_SQL' ORDER BY marks DESC)WHERE ROWNUM <= 10 ;

E
SELECT student_id, marks, ROWNUM "Rank" FROM (SELECT student_id, marks FROM students ORDER BY marks) WHERE ROWNUM <= 10 AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99' AND course_id = 'INT_SQL';

Note: Not available
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Question: Which of the following views should a user query to display the columns associated with the constraints on a table owned by the user?
A
USER_CONSTRAINTS

B
USER_OBJECTS

C
ALL_CONSTRAINTS

D
USER_CONS_COLUMNS

E
USER_COLUMNS

Note: Not available
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Question: What does the TRUNCATE statement do?
A
Removes the table

B
Removes all rows from a table

C
Shortens the table to 10 rows

D
Removes all columns from a table

Note: Not available
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Question: Examine the two SQL statements given below: 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?

Question: What will happen if you query the emp table shown below: select empno,DISTINCT ename,Salary from emp;

Question: How many join conditions should be there to avoid a Cartesion Join for joining three tables?

Question: Which operator will be evaluated first in the statement: select (2+3*4/2-8) from dual:

Question: Which of the following SQL statements returns a numeric value?

Question: Which of the following SELECT statements will get the result 'elloworld' from the string 'HelloWorld'?

Question: You want to list names of the employees who have been with the company for more than five years. Which of the following SQL statements will display the required results?

Question: Which of the following views should a user query to display the columns associated with the constraints on a table owned by the user?

Question: What does the TRUNCATE statement do?