What does SQL stand for?
A. Simple Query Language
B. Structured Query Language
C. Standard Query Language
D. Sequential Query Language
Answer: B
Which SQL command is used to retrieve data from a database?
A. GET
B. SELECT
C. FETCH
D. RETRIEVE
Answer: B
Which SQL command is used to update existing records in a table?
A. MODIFY
B. UPDATE
C. ALTER
D. CHANGE
Answer: B
What does the acronym CRUD stand for in database management?
A. Create, Retrieve, Update, Delete
B. Compute, Report, Utilize, Delete
C. Choose, Remove, Update, Design
D. Correct, Refactor, Use, Debug
Answer: A
Which SQL command is used to delete records from a database table?
A. REMOVE
B. ERASE
C. DELETE
D. DROP
Answer: C
In SQL, which clause is used to filter records based on a specified condition?
A. FILTER BY
B. HAVING
C. WHERE
D. CONDITION
Answer: C
What SQL keyword is used to retrieve unique records from a query result?
A. UNIQUE
B. DISTINCT
C. UNIQUE
D. DISTINCT
Answer: D
Which SQL command is used to add a new table to a database?
A. CREATE TABLE
B. ADD TABLE
C. INSERT TABLE
D. DEFINE TABLE
Answer: A
What does the SQL command “SELECT * FROM Customers;” do?
A. Selects all customers from the Customers table
B. Selects the first customer from the Customers table
C. Selects customers with a specific ID from the Customers table
D. Selects a random customer from the Customers table
Answer: A
Which SQL command is used to sort the result set in ascending order?
A. SORT ASC
B. ORDER BY ASC
C. SORT BY ASC
D. ORDER ASC
Answer: B
In SQL, what does the GROUP BY clause do?
A. Groups rows that have the same values into summary rows
B. Groups rows based on the primary key
C. Groups rows in random order
D. Groups rows based on the foreign key
Answer: A
What is the purpose of SQL constraints in a database?
A. To speed up query execution
B. To restrict the types of data that can be inserted into a table
C. To join tables together
D. To display the query results in a specific format
Answer: B
Which SQL command is used to add a new row to a table?
A. ADD ROW
B. APPEND ROW
C. INSERT INTO
D. CREATE ROW
Answer: C
What does the SQL command “SELECT COUNT(*) FROM Orders;” do?
A. Counts the total number of orders in the Orders table
B. Selects the first order from the Orders table
C. Counts the number of unique orders in the Orders table
D. Counts the number of orders placed on a specific date
Answer: A
Which SQL command is used to change the structure of an existing table?
A. MODIFY TABLE
B. ALTER TABLE
C. CHANGE TABLE
D. UPDATE TABLE
Answer: B
In SQL, which operator is used to combine the result sets of two or more SELECT statements?
A. COMBINE
B. AND
C. OR
D. UNION
Answer: D
What does the SQL command “SELECT AVG(Price) FROM Products;” do?
A. Calculates the total price of all products
B. Finds the product with the average price
C. Calculates the average price of all products
D. Sorts products by price in ascending order
Answer: C
Which SQL command is used to remove a table from a database?
A. REMOVE TABLE
B. DELETE TABLE
C. DROP TABLE
D. ERASE TABLE
Answer: C
In SQL, what does the LIKE operator do?
A. Matches exact values in a column
B. Matches values that are not in a specified list
C. Matches patterns in a column
D. Matches values greater than or equal to a specified value
Answer: C
What does the SQL command “SELECT MAX(Age) FROM Students;” do?
A. Selects the maximum age of all students
B. Selects the first student with the maximum age
C. Selects the oldest student
D. Selects the youngest student
Answer: A
Which SQL command is used to add a new column to an existing table?
A. ADD COLUMN
B. INSERT COLUMN
C. CREATE COLUMN
D. ALTER COLUMN
Answer: A
In SQL, what does the JOIN clause do?
A. Combines rows from two or more tables based on a related column between them
B. Joins tables randomly
C. Filters rows based on a specified condition
D. Joins tables based on their primary keys
Answer: A
What does the SQL command “SELECT MIN(Price) FROM Products;” do?
A. Selects the minimum price of all products
B. Finds the product with the minimum price
C. Selects the most expensive product
D. Selects the cheapest product
Answer: A
Which SQL command is used to remove a specific row from a table?
A. DELETE
B. ERASE
C. REMOVE
D. DROP
Answer: A
What does the SQL command “SELECT SUM(Quantity) FROM Orders;” do?
A. Calculates the total number of orders
B. Calculates the total quantity of all orders
C. Calculates the average quantity of orders
D. Calculates the maximum quantity of orders
Answer: B
Which SQL command is used to limit the number of rows returned in a query result?
A. RESTRICT
B. LIMIT
C. TOP
D. SAMPLE
Answer: B
In SQL, what does the ORDER BY clause do?
A. Orders rows in ascending or descending order based on a specified column
B. Filters rows based on a specified condition
C. Groups rows that have the same values into summary rows
D. Joins rows from two or more tables based on a related column
Answer: A
What does the SQL command “SELECT DISTINCT Category FROM Products;” do?
A. Selects all categories from the Products table
B. Selects the first category from the Products table
C. Selects unique categories from the Products table
D. Selects random categories from the Products table
Answer: C
Which SQL command is used to rename a table?
A. RENAME TABLE
B. ALTER TABLE
C. CHANGE TABLE
D. MODIFY TABLE
Answer: A
In SQL, what does the UNION operator do?
A. Combines result sets of two or more SELECT statements, including duplicates
B. Combines result sets of two or more SELECT statements, excluding duplicates
C. Joins rows from two or more tables based on a related column
D. Filters rows based on a specified condition
Answer: B
What does the SQL command “SELECT COUNT(DISTINCT Country) FROM Customers;” do?
A. Counts the total number of customers
B. Counts the number of unique countries in the Customers table
C. Counts the number of orders placed in each country
D. Counts the number of customers from a specific country
Answer: B
Which SQL command is used to add a primary key to a table?
A. SET PRIMARY KEY
B. ADD PRIMARY KEY
C. CREATE PRIMARY KEY
D. DEFINE PRIMARY KEY
Answer: B
In SQL, what does the LIKE ‘%pattern%’ clause do?
A. Matches any single character
B. Matches any number of characters (including zero characters)
C. Matches a specific number of characters
D. Matches exactly one character
Answer: B
What does the SQL command “SELECT AVG(Salary) FROM Employees WHERE Department = ‘IT’;” do?
A. Calculates the average salary of all employees
B. Calculates the average salary of IT employees
C. Calculates the total salary of IT employees
D. Calculates the minimum salary of IT employees
Answer: B
Which SQL command is used to create a view in a database?
A. CREATE VIEW
B. ADD VIEW
C. DEFINE VIEW
D. INSERT VIEW
Answer: A
In SQL, what does the EXISTS operator do?
A. Checks whether a subquery returns any rows
B. Checks whether a column exists in a table
C. Checks whether a value exists in a column
D. Checks whether a table exists in a database
Answer: A
What is the purpose of the SQL command “GROUP BY”?
A. To order rows in a specified column
B. To filter rows based on a condition
C. To group rows that have the same values into summary rows
D. To join rows from two or more tables based on a related column
Answer: C
Which SQL command is used to remove a column from an existing table?
A. DELETE COLUMN
B. DROP COLUMN
C. REMOVE COLUMN
D. ERASE COLUMN
Answer: B
What does the SQL command “SELECT TOP 10 * FROM Products;” do?
A. Selects the top 10 products from the Products table
B. Selects the first 10 products from the Products table
C. Selects the last 10 products from the Products table
D. Selects 10 random products from the Products table
Answer: A
In SQL, what does the ORDER BY clause with DESC do?
A. Orders rows in descending order based on a specified column
B. Orders rows in ascending order based on a specified column
C. Orders rows randomly
D. Orders rows based on a secondary column
Answer: A
Which SQL command is used to change the data type of a column in an existing table?
A. MODIFY COLUMN
B. ALTER COLUMN
C. CHANGE COLUMN
D. UPDATE COLUMN
Answer: B
In SQL, what does the INNER JOIN keyword do?
A. Returns all rows from both tables, where the join condition is met
B. Returns all rows from the left table, and the matched rows from the right table
C. Returns all rows from the right table, and the matched rows from the left table
D. Returns only rows that have NULL values in the joined columns
Answer: A
What does the SQL command “SELECT MAX(Quantity), MIN(Quantity) FROM Orders;” do?
A. Selects the maximum and minimum quantity of all orders
B. Selects the first order with the maximum and minimum quantity
C. Selects the maximum and minimum quantity for each order
D. Selects the average quantity of all orders
Answer: A
Which SQL command is used to create a temporary table?
A. CREATE TEMPORARY TABLE
B. ADD TEMPORARY TABLE
C. DEFINE TEMPORARY TABLE
D. INSERT TEMPORARY TABLE
Answer: A
In SQL, what does the NOT LIKE operator do?
A. Matches exact values in a column
B. Matches values that are not in a specified list
C. Matches patterns that do not match the specified pattern
D. Matches values greater than or equal to a specified value
Answer: C
What does the SQL command “SELECT DISTINCT LastName FROM Employees ORDER BY LastName;” do?
A. Selects all last names from the Employees table and orders them in descending order
B. Selects unique last names from the Employees table and orders them in ascending order
C. Selects the first last name from the Employees table and orders it in ascending order
D. Selects random last names from the Employees table and orders them in descending order
Answer: B
Which SQL command is used to add a foreign key constraint to a table?
A. ADD CONSTRAINT
B. ADD FOREIGN KEY
C. DEFINE FOREIGN KEY
D. INSERT FOREIGN KEY
Answer: B
In SQL, what does the BETWEEN operator do?
A. Matches values that are within a specified range
B. Matches values that are outside a specified range
C. Matches values that are greater than or equal to a specified value
D. Matches values that are less than or equal to a specified value
Answer: A
What does the SQL command “SELECT * FROM Orders WHERE OrderDate BETWEEN ‘2023-01-01’ AND ‘2023-12-31’;” do?
A. Selects orders placed between January 1, 2023, and December 31, 2023
B. Selects the first order placed on January 1, 2023
C. Selects orders placed on January 1, 2023
D. Selects orders placed after January 1, 2023
Answer: A
Which SQL command is used to remove a primary key constraint from a table?
A. DELETE PRIMARY KEY
B. REMOVE PRIMARY KEY
C. DROP PRIMARY KEY
D. ERASE PRIMARY KEY
Answer: C