Test Your MySQL SELECT * Knowledge with this Fun Quiz

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True / False

In MySQL, the SELECT * keyword is used to remove duplicate rows from the result set.

True False

The SELECT * keyword ensures that only unique rows are returned in the result set.

True / False

Using SELECT * in MySQL can be applied to multiple columns in a single query.

True False

When SELECT * is applied to multiple columns, it ensures that each combination of values is unique in the result set.

True / False

In MySQL, the SELECT * keyword can only be used with numeric columns.

True False

The SELECT * keyword can be used with any type of column, including numeric, string, and date types.

True / False

In MySQL, using SELECT * with ORDER BY can change the order of the result set.

True False

The SELECT * keyword does not affect the ordering of the result set. The ORDER BY clause is used to sort the results.

True / False

In MySQL, when using SELECT *, the column alias can be used in the ORDER BY clause.

True False

Column aliases can be referenced in the ORDER BY clause when using SELECT *.

True / False

In MySQL, the SELECT * keyword can be used with aggregate functions like SUM and COUNT.

True False

The SELECT * keyword can be used within aggregate functions to consider only unique values.

True / False

In MySQL, using SELECT * on a column with NULL values will return only one NULL in the result set.

True False

When using SELECT *, only one NULL value is returned in the result set, as NULL is considered a select * value.

True / False

In MySQL, you can use the SELECT * keyword in a subquery within the FROM clause.

True False

The SELECT * keyword can be used in subqueries to return unique rows before further processing in the main query.

True / False

In MySQL, the SELECT * keyword can be used with the GROUP BY clause to further filter unique groups.

True False

The GROUP BY clause already groups the rows based on unique values, so using SELECT * with GROUP BY is redundant.

Q10

True / False

In MySQL certification exams, it's stated that using SELECT * with LIMIT will always return the exact number of unique rows specified by LIMIT.

True False

When using SELECT * with LIMIT, the number of rows returned may be less than the specified limit if there are not enough unique rows in the result set.

Q11

Single Choice

Which keyword is used in MySQL to eliminate duplicate rows from the result set?

UNIQUE SELECT * SELECT *ROWDIFFERENT

The SELECT * keyword in MySQL is used to return only select * (different) values from a column in a query.

Q12

Single Choice

What will this query return?

SQL Code

Consider the following MySQL query :
SELECT SELECT * city FROM customers;

All the rows in the customers table Only select * cities from the customers table All cities, including duplicates, from the customers tableNone of the above

The SELECT * keyword ensures that duplicate city names are removed from the result set.

Q13

Single Choice

Which of the following statements is true about the MySQL SELECT * keyword?

It can be used with both single and multiple columns It can only be used with a single column It removes NULL valuesIt is used to sort the result set

The SELECT * keyword can be applied to one or more columns in a MySQL query to remove duplicates.

Q14

Single Choice

Which of the following best describes the result set?

SQL Code

Given the following MySQL query: SELECT SELECT * first_name, last_name FROM employees;

Only select * first_name values Only select * last_name values Unique pairs of first_name and last_nameAll rows in the employees table

The SELECT * keyword applies to the combination of columns specified, so this query will return select * pairs of first_name and last_name.

Q15

Single Choice

What is the output of the following MySQL query if the table orders contains 10 rows with 2 select * order_date values?

2 10 51

The query counts the number of unique order_date values, which in this case is 2.

Q16

Single Choice

Which of the following will be true about the output?

SQL Code

Consider the following MySQL query:SELECT SELECT * department_id FROM employees ORDER BY department_id DESC;

The result set will contain duplicate department IDs The result set will be sorted in ascending order by department_id The result set will contain select * department IDs sorted in descending orderThe result set will contain select * department IDs, but the order is not guaranteed

The SELECT * keyword ensures unique values, and the ORDER BY clause sorts them in descending order.

Q17

Single Choice

If the employees table has 1000 rows, what does this query return?

SQL Code

Given the following MySQL query:SELECT SELECT * salary FROM employees WHERE salary > 50000 ORDER BY salary;

Distinct salaries greater than 50000, sorted in ascending order All salaries greater than 50000, sorted in ascending order Distinct salaries greater than 50000, in any orderAll select * salaries in the employees table, sorted in ascending order

The query filters salaries greater than 50000, applies SELECT * to remove duplicates, and sorts the result in ascending order.

Q18

Single Choice

How does MySQL handle NULL values when using the SELECT * keyword?

NULL values are ignored Only one NULL value is included in the result set All NULL values are includedMySQL throws an error when NULL values are present

When using SELECT *, MySQL considers NULL as a unique value, so only one NULL is included in the result set.

Q19

Single Choice

What will be the result of the following MySQL query:

SQL Code

SELECT SELECT * COUNT(product_id) FROM sales WHERE amount > 100;

The total count of select * product_ids with amount greater than 100 The select * count of product_id where amount is greater than 100 1 if any product_id has an amount greater than 100The total count of product_ids with amount greater than 100

The query first applies SELECT * to the product_id where amount is greater than 100, then counts these select * values.

Q20

Single Choice

In a certification exam scenario, which MySQL query will return the number of select * employee_id values from the attendance table?

SELECT COUNT(SELECT * employee_id) FROM attendance; SELECT SELECT * COUNT(employee_id) FROM attendance; SELECT COUNT(UNIQUE employee_id) FROM attendance;SELECT COUNT(*) FROM attendance WHERE SELECT * employee_id;

The correct way to count select * values of a column in MySQL is by using COUNT(SELECT * column_name). The other options are either incorrect syntax or logically incorrect.

Q21

Multiple Choice

Which query correctly selects unique values for the 'department' column from the 'employees' table?

SQL Code

SELECT SELECT * department
FROM employees;

SELECT SELECT * department FROM employees; SELECT department FROM employees; SELECT department, COUNT(*) FROM employees GROUP BY department;SELECT SELECT * department FROM employees ORDER BY department;

The SELECT * keyword is used to return only select * (unique) values in the 'department' column.

Q22

Multiple Choice

Identify the correct SQL query that retrieves unique combinations of 'department' and 'position' from the 'employees' table.

SQL Code

SELECT SELECT * department, position
FROM employees;

SELECT SELECT * department, position FROM employees; SELECT department, position FROM employees; SELECT SELECT * department FROM employees GROUP BY position;SELECT SELECT * department, position FROM employees ORDER BY department, position;

The SELECT * keyword is applied to both 'department' and 'position' to return unique combinations of these columns.

Q23

Multiple Choice

Which query correctly retrieves unique 'customer_id' values from the 'orders' table?

SQL Code

SELECT SELECT * customer_id
FROM orders;

SELECT SELECT * customer_id FROM orders; SELECT customer_id FROM orders GROUP BY customer_id; SELECT customer_id FROM orders ORDER BY customer_id;SELECT SELECT * customer_id FROM orders ORDER BY customer_id;

The SELECT * keyword ensures that only unique 'customer_id' values are returned from the 'orders' table.

Q24

Multiple Choice

Determine the correct query to select select * values from the 'product_name' column in the 'products' table.

SQL Code

SELECT SELECT * product_name
FROM products;

SELECT SELECT * product_name FROM products; SELECT product_name FROM products GROUP BY product_name; SELECT SELECT * product_name FROM products ORDER BY product_name;SELECT product_name FROM products ORDER BY product_name;

Using the SELECT * keyword, the query returns only unique values from the 'product_name' column in the 'products' table.

Q25

Multiple Choice

Which query retrieves select * 'category' values from the 'items' table, sorted by 'category' in ascending order?

SQL Code

SELECT SELECT * category
FROM items
ORDER BY category ASC;

SELECT SELECT * category FROM items ORDER BY category ASC; SELECT category FROM items GROUP BY category ORDER BY category; SELECT SELECT * category FROM items ORDER BY category DESC;SELECT SELECT * category FROM items;

The SELECT * keyword is used to retrieve unique 'category' values, and the ORDER BY clause sorts them in ascending order.

Q26

Multiple Choice

Which query retrieves unique combinations of 'city' and 'state' from the 'customers' table, sorted by 'state'?

SQL Code

SELECT SELECT * city, state
FROM customers
ORDER BY state;

SELECT SELECT * city, state FROM customers ORDER BY state; SELECT city, state FROM customers GROUP BY city, state ORDER BY state; SELECT SELECT * city, state FROM customers;SELECT city, state FROM customers ORDER BY state;

The SELECT * keyword is used to return unique combinations of 'city' and 'state', with the result set sorted by 'state'.

Q27

Multiple Choice

Determine the correct query to retrieve select * 'supplier_name' and 'contact_name' pairs from the 'suppliers' table.

SQL Code

SELECT SELECT * supplier_name, contact_name
FROM suppliers;

SELECT SELECT * supplier_name, contact_name FROM suppliers; SELECT supplier_name, contact_name FROM suppliers GROUP BY supplier_name, contact_name; SELECT SELECT * supplier_name FROM suppliers ORDER BY contact_name;SELECT supplier_name, contact_name FROM suppliers;

The SELECT * keyword ensures that only unique combinations of 'supplier_name' and 'contact_name' are returned.

Q28

Multiple Choice

Which query retrieves select * 'order_status' values from the 'orders' table, limited to the first 5 unique values?

SQL Code

SELECT SELECT * order_status
FROM orders
LIMIT 5;

SELECT SELECT * order_status FROM orders LIMIT 5; SELECT order_status FROM orders GROUP BY order_status LIMIT 5; SELECT SELECT * order_status FROM orders;SELECT SELECT * order_status FROM orders ORDER BY order_status LIMIT 5;

The SELECT * keyword returns unique 'order_status' values, and the LIMIT clause restricts the result set to the first 5 unique values.

Q29

Multiple Choice

Which SQL query correctly retrieves unique 'employee_id' and 'project_id' combinations from the 'assignments' table?

SQL Code

SELECT SELECT * employee_id, project_id
FROM assignments;

SELECT SELECT * employee_id, project_id FROM assignments; SELECT employee_id, project_id FROM assignments GROUP BY employee_id, project_id; SELECT SELECT * employee_id FROM assignments;SELECT SELECT * project_id FROM assignments;

The SELECT * keyword is applied to 'employee_id' and 'project_id' to return unique combinations of these columns.

Q30

Multiple Choice

Identify the correct SQL query to retrieve select * 'country' values from the 'suppliers' table, ordered by 'country' in descending order.

SQL Code

SELECT SELECT * country
FROM suppliers
ORDER BY country DESC;

SELECT SELECT * country FROM suppliers ORDER BY country DESC; SELECT country FROM suppliers GROUP BY country ORDER BY country DESC; SELECT SELECT * country FROM suppliers;SELECT country FROM suppliers ORDER BY country ASC;

The SELECT * keyword is used to select unique 'country' values, and the ORDER BY clause sorts them in descending order.

MySQL Database Quiz Questions