Back
0

Basic SQL Quiz

Description: Basic SQL Quiz
Number of Questions: 18
Created by:
Tags: sql
Start the Quiz
Attempted 0/18 Correct 0 Score 0
‹
›

What does SQL stand for?

sql

  1. Strong Question Language

  2. Structured Question Language

  3. Structured Query Language

Show answer
Correct Option: C

Which SQL statement is used to extract data from a database?
sql

  1. GET

  2. OPEN

  3. EXTRACT

  4. SELECT

  5. QUERY

Show answer
Correct Option: D
Explanation:

To extract data from a database using SQL, the correct option is D. SELECT.

Explanation:

The SELECT statement is used to extract or retrieve data from a database. It is one of the most commonly used SQL statements and forms the core of most database queries. The SELECT statement is followed by the columns or fields that need to be retrieved from the table or tables specified in the FROM clause. The WHERE clause can be used to filter the results based on specific conditions.

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

A. GET: This option is not a valid SQL statement. GET is not a SQL keyword and is not used to extract data from a database.

B. OPEN: This option is not used to extract data from a database. OPEN is used to open a cursor variable, which can then be used to fetch data from a result set.

C. EXTRACT: This option is used to extract parts of a date or time value such as year, month, day, hour, minute, or second. It is not used to extract data from a database table.

D. SELECT: This option is the correct answer. The SELECT statement is used to extract or retrieve data from a database.

E. QUERY: This option is not a specific SQL statement. Query is a general term used to refer to any SQL statement that retrieves data from a database. However, it is not a specific SQL keyword used to extract data.

Therefore, the answer is:

The Answer is: D. SELECT

Which SQL statement is used to update data in a database?
sql

  1. UPDATE

  2. SAVE AS

  3. MODIFY

  4. SAVE

Show answer
Correct Option: A

Which SQL statement is used to delete data from a database?
sql

  1. TRUNCATE

  2. DELETE

  3. REMOVE

Show answer
Correct Option: B

Which SQL statement is used to insert new data in a database?
sql

  1. ADD RECORD

  2. ADD INTO

  3. INSERT

  4. ADD NEW

Show answer
Correct Option: C

With SQL, how do you select a column named "FirstName" from a table named "Persons"?
sql

  1. EXTRACT FirstName FROM Persons

  2. SELECT FirstName FROM Persons

  3. SELECT Persons.FirstName

Show answer
Correct Option: B
Explanation:

To solve this question, the user needs to have a basic understanding of SQL and the syntax used to select specific columns from a table. In SQL, the SELECT statement is used to retrieve data from a database. The user must know how to specify the column name and the table name in the SELECT statement to retrieve the desired data.

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

A. EXTRACT FirstName FROM Persons: This option is incorrect. The EXTRACT keyword is used to retrieve date and time information from a specified value, not to select specific columns from a table.

B. SELECT FirstName FROM Persons: This option is correct. The SELECT statement followed by the column name (FirstName) and the table name (Persons) retrieves the data from the specified column in the specified table.

C. SELECT Persons.FirstName: This option is also correct. The SELECT statement can be written in the format of "SELECT TableName.ColumnName" to specify the table name and column name. In this case, the column name (FirstName) is preceded by the table name (Persons) and separated by a dot (.) to retrieve the desired data.

The Answer is: B

With SQL, how do you select all the columns from a table named "Persons"?
sql

  1. SELECT [all] FROM Persons

  2. SELECT All Persons

  3. SELECT *.Persons

  4. SELECT * FROM Persons

Show answer
Correct Option: D

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

  1. SELECT [all] FROM Persons WHERE FirstName='Peter'

  2. SELECT * FROM Persons WHERE FirstName LIKE 'Peter'

  3. SELECT [all] FROM Persons WHERE FirstName LIKE 'Peter'

  4. SELECT * FROM Persons WHERE FirstName='Peter'

Show answer
Correct Option: D

With SQL, how do you select all the records from a table named "Persons" where the value of the column "FirstName" starts with an "a"?
sql

  1. SELECT * FROM Persons WHERE FirstName='%a%'

  2. SELECT * FROM Persons WHERE FirstName LIKE '%a'

  3. SELECT * FROM Persons WHERE FirstName='a'

  4. SELECT * FROM Persons WHERE FirstName LIKE 'a%'

  5. SELECT * FROM Persons WHERE FirstName='a'"

Show answer
Correct Option: D

The OR operator displays a record if ANY conditions listed are true. The AND operator displays a record if ALL of the conditions listed are true
sql

  1. True

  2. False

Show answer
Correct Option: A

Given an employees table as follows: empid name managerid a1 bob NULL b1 jim a1 B2 tom a1 What value will select count(*) from employees return?

sql

  1. 1

  2. 2

  3. 3

  4. none of the above

Show answer
Correct Option: C

AI Explanation

To determine the value that will be returned by the query select count(*) from employees, let's analyze the given employees table:

empid | name | managerid
------------------------
a1    | bob  | NULL
b1    | jim  | a1
B2    | tom  | a1

The query select count(*) from employees counts the number of rows in the employees table. It does not consider NULL values.

In this case, there are three rows in the table: (a1, bob, NULL), (b1, jim, a1), and (B2, tom, a1). Therefore, the query will return a value of 3.

Therefore, the correct answer is C) 3.

The result of a SELECT statement can contain duplicate rows.

sql

  1. True

  2. False

Show answer
Correct Option: A

Sometimes the expression "select count(*)" will return fewer rows than the expression "select count(value)".

sql

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

To solve this question, one needs to understand the difference between count(*) and count(column_name).

count(*) returns the total number of rows in the table, whereas count(column_name) returns the number of non-null values for the given column.

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

A. True: This option is false. count(*) will always return the same value as the number of rows in the table, while count(column_name) will return the number of non-null values for the given column. Thus, it is possible for count(column_name) to return a higher value than count(*), but not a lower value.

B. False: This option is correct. count(*) returns the total number of rows in the table, whereas count(column_name) returns the number of non-null values for the given column. Thus, it is not possible for count(column_name) to return fewer rows than count(*).

The Answer is: B

What type of lock will deny users any access to a table?

sql

  1. EXPLICIT

  2. IMPLICIT

  3. EXCLUSIVE

  4. SHARED

  5. READ ONLY

Show answer
Correct Option: C

Which of the following is the correct SQL statement to use to remove rows from a table?

sql

  1. DROP

  2. REMOVE ROW

  3. DELETE

  4. DELETE ROW

Show answer
Correct Option: C

AI Explanation

To remove rows from a table in SQL, the correct statement to use is the DELETE statement. Let's go through each option to understand why it is correct or incorrect:

Option A) DROP - The DROP statement is used to delete an entire table or database, not specific rows within a table. Therefore, this option is incorrect.

Option B) REMOVE ROW - There is no specific SQL statement called REMOVE ROW. Therefore, this option is incorrect.

Option C) DELETE - The DELETE statement is used to remove one or more rows from a table based on a specific condition. It allows you to specify a WHERE clause to determine which rows should be deleted. This is the correct statement to use for removing rows from a table. Therefore, this option is correct.

Option D) DELETE ROW - There is no specific SQL statement called DELETE ROW. Therefore, this option is incorrect.

The correct answer is C) DELETE. This option is correct because the DELETE statement is used to remove one or more rows from a table based on a specific condition.

The only way to join two tables is by using standard, ANSI syntax.

sql

  1. True

  2. False

Show answer
Correct Option: B

AI Explanation

To answer this question, you need to understand the different ways to join tables in SQL.

Option A) True - This option is incorrect because there are multiple ways to join tables in SQL, not just by using standard ANSI syntax. Other join types include INNER JOIN, OUTER JOIN (LEFT, RIGHT, FULL), CROSS JOIN, etc.

Option B) False - This option is correct because it acknowledges that the only way to join two tables is not limited to standard ANSI syntax. SQL provides various join types and syntax options to join tables based on the specific requirements of the query.

The correct answer is B) False. This option is correct because there are multiple ways to join tables in SQL, not just by using standard ANSI syntax.

A NULL value is treated as a blank or 0.

sql

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

To solve this question, the user needs to know the concept of NULL value and its treatment in programming.

The correct answer is:

B. False

Explanation:

In programming, a NULL value represents the absence of a value or an unknown value. It is not the same as a blank or 0. When a variable is assigned a NULL value, it means that no value has been assigned to it or that the value is unknown.

In SQL, for example, NULL values cannot be compared using the equality operator (=) or inequality operator (<>). Instead, you have to use the IS NULL or IS NOT NULL operator to check for NULL values.

Therefore, option B is the correct answer as a NULL value is not treated as a blank or 0.

The left outer join is one type of outer join. Another one is the.

sql

  1. right

  2. full

  3. right outer

  4. full outer

  5. all of the above

Show answer
Correct Option: E
- Hide questions
ADVERTISEMENT

Find more quizzes from top tags

general knowledge
3615 Quizzes
119858 Questions
 technology
307 Quizzes
36705 Questions
 sports
963 Quizzes
19148 Questions
 history
1187 Quizzes
13475 Questions
 physics
598 Quizzes
13441 Questions
 biology
1160 Quizzes
12174 Questions
 science & technology
551 Quizzes
11015 Questions
 chemistry
490 Quizzes
9892 Questions
 maths
518 Quizzes
9324 Questions
 softskills
0 Quizzes
7131 Questions