Tag: databases

Questions Related to databases

Which of the following is not a grouping function?
technology databases

  1. DISTINCT

  2. SUM

  3. MIN

  4. COUNT

  5. All of the above.

  6. None of these above.

Show answer
Correct Option: A
Explanation:

To answer this question, the user needs to know about grouping functions in SQL.

Grouping functions are used to group rows of data together and perform calculations on them. Each of the options listed is a grouping function except for one.

A. DISTINCT: This is a grouping function that returns the unique values of a column.

B. SUM: This is a grouping function that returns the sum of the values in a column.

C. MIN: This is a grouping function that returns the minimum value of a column.

D. COUNT: This is a grouping function that returns the number of rows in a table or the number of non-null values in a column.

E. All of the above: This option is incorrect because all of the options listed are grouping functions except for one.

F. None of these above: This option is also incorrect because one of the options listed is not a grouping function.

The Answer is: A. DISTINCT

Which of the following is not an Oracle DML function?
technology databases

  1. DECODE

  2. TRUNCATE

  3. TO_CHAR

  4. NVL

  5. Trick question, all of these are Oracle DML functions.

Show answer
Correct Option: B
Explanation:

To solve this question, the user needs to know the meaning of Oracle DML (Data Manipulation Language) functions and should be able to identify which of the given options is not an Oracle DML function.

Oracle DML functions are used to manipulate data stored within the database. They are used to insert, update, select, and delete data from tables. These functions are used to modify the data values present in the database.

Now let's go through each option and explain why it is right or wrong:

A. DECODE: This is an Oracle DML function. It is used to compare expressions and return a value when the first matching condition is found.

B. TRUNCATE: This is not an Oracle DML function. It is a DDL (Data Definition Language) command used to remove all data from a table, but not its structure.

C. TO_CHAR: This is an Oracle DML function. It is used to convert a number or date to a string.

D. NVL: This is an Oracle DML function. It is used to replace NULL values with another value.

E. Trick question, all of these are Oracle DML functions: This statement is incorrect. Option B (TRUNCATE) is not an Oracle DML function.

Therefore, the answer is: B. TRUNCATE

The || is is an example of what function SELECT last_name || ', ' || first_name || ' ' || middle_name FROM employees;
technology databases

  1. Incantination

  2. Integration

  3. Continuation

  4. Concatenation

  5. Pipeline

  6. None of the above

Show answer
Correct Option: D
Explanation:

To solve this question, the user needs to know the SQL syntax and the concept of concatenation.

The given SQL statement is using the || operator to join or concatenate multiple columns together.

Now, let's go through each option and explain why it is right or wrong:

A. Incantination: This option is incorrect as "Incantation" is not a valid SQL function or concept.

B. Integration: This option is incorrect as "Integration" is not a valid SQL function or concept.

C. Continuation: This option is incorrect as "Continuation" is not a valid SQL function or concept.

D. Concatenation: This option is correct. The || operator is used to concatenate or combine two or more strings in SQL, resulting in a single string that contains all the characters from the original strings.

E. Pipeline: This option is incorrect as "Pipeline" is not a valid SQL function or concept.

F. None of the above: This option is incorrect as option D, "Concatenation", is the correct answer.

Therefore, the answer is: D. Concatenation

Assuming the date and time is 09/09/2009 09:09:09, what value will the following statement return SELECT TO_CHAR(TRUNC(SYSDATE),'MM/DD/YYYY HH24:MI:SS') FROM dual;
technology databases

  1. 09/09/2009 00:00:00

  2. 09/09/2009 09:09:09AM

  3. 09/09/2009

  4. 09/09/2009 09:09:09

  5. None of the above.

Show answer
Correct Option: A
Explanation:

The given statement is:

SELECT TO_CHAR(TRUNC(SYSDATE),'MM/DD/YYYY HH24:MI:SS') FROM dual;

Let's break down the statement:

  1. TRUNC(SYSDATE): This truncates the current date and time to the nearest day, setting the time component to 00:00:00.

  2. TO_CHAR(TRUNC(SYSDATE),'MM/DD/YYYY HH24:MI:SS'): This converts the truncated date and time to a string format with the specified format mask.

Considering the given date and time is 09/09/2009 09:09:09, when we truncate this date and time, the time component will be set to 00:00:00, resulting in 09/09/2009 00:00:00.

Therefore, the statement will return "09/09/2009 00:00:00".

The correct answer is A) 09/09/2009 00:00:00.

Select the best answer. Which listed attribute is an invalid attribute of an Explicit cursor.
technology databases

  1. %NOTFOUND

  2. %FOUND

  3. %ROWCOUNT

  4. %ISOPEN

  5. None of the above. All of these are valid.

Show answer
Correct Option: E
Explanation:

To answer this question, the user needs to have knowledge of explicit cursors in SQL.

The explicit cursor is a SELECT statement that gets declared in the declaration section of PL/SQL block, and it is used to retrieve more than one row from the table.

Now, let's examine each option to see which attribute is invalid for an explicit cursor:

A. %NOTFOUND: This attribute is used to check whether the cursor returns no rows. It is a valid attribute of an explicit cursor.

B. %FOUND: This attribute is used to check whether the cursor returns rows. It is a valid attribute of an explicit cursor.

C. %ROWCOUNT: This attribute is used to return the number of rows affected by the most recent DML statement. It is a valid attribute of an explicit cursor.

D. %ISOPEN: This attribute is used to check whether the cursor is open or not. It is a valid attribute of an explicit cursor.

E. None of the above. All of these are valid: This option is incorrect because it is asking for an invalid attribute. All of the attributes listed in the question (A, B, C, and D) are valid attributes of an explicit cursor.

Therefore, the correct answer is:

The Answer is: E

Where do you declare an explicit cursor in the PL/SQL language?
technology databases

  1. In the PL/SQL working storage section

  2. In the PL/SQL declaration section

  3. In the PL/SQL body section

  4. In the PL/SQL exception section

  5. None of the above

Show answer
Correct Option: B
Explanation:

To declare an explicit cursor in the PL/SQL language, the user needs to know how to write PL/SQL code and the concept of cursors.

An explicit cursor is a cursor that is defined and managed by the user. It requires the user to declare a cursor variable that references the cursor and then define the SQL statement that will be executed when the cursor is opened.

With that in mind, the correct answer is:

B. In the PL/SQL declaration section

The declaration section of a PL/SQL block is where variables, constants, and cursors are declared. In this section, the user can declare the explicit cursor variable by specifying its name, data type, and the query to be executed. Once the cursor variable is declared, the user can then open, fetch, and close the cursor in the body section of the block.

Option A is incorrect because the PL/SQL working storage section does not exist.

Option C is incorrect because the PL/SQL body section is where the logic of the block is implemented, not where the cursor is declared.

Option D is incorrect because the PL/SQL exception section is where exception handling code is written.

Option E is incorrect because one of the above options (Option B) is the correct answer.

Therefore, the answer is: B. In the PL/SQL declaration section.

Select the best answer. This is an example of what _____ type of cursor? DECLARE l_date DATE; BEGIN SELECT TRUNC(SYSDATE) INTO l_date FROM DUAL; END;
technology databases

  1. Explicit

  2. Implicit

  3. Select

  4. PL/SQL

  5. None of the above

Show answer
Correct Option: B

Select the best answer. This is an example of what _____ type of cursor? DECLARE l_date DATE; CURSOR c1 IS SELECT TRUNC(SYSDATE) FROM DUAL; BEGIN OPEN c1; FETCH c1 INTO l_date; CLOSE c1; END;
technology databases

  1. Explicit

  2. Implicit

  3. Select

  4. PL/SQL

  5. None of the above.

Show answer
Correct Option: A

Select the best answer to complete this variable declaration for a record. DECLARE l_foo_table SOME_TABLE_________; BEGIN ...
technology databases

  1. %ROWTYPE

  2. %TABLE

  3. %COLUMNTYPE

  4. %TYPE

  5. None of the above

Show answer
Correct Option: A

Select the best answer to complete this variable declaration for a column value. DECLARE l_foo_column_id SOME_TABLE.SOME_COLUMN_________; BEGIN ...
technology databases

  1. %ID

  2. %ROWTYPE

  3. %TYPE

  4. %COLUMNTYPE

  5. None of the above.

Show answer
Correct Option: C