Why MySQL is widely used - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select all records from the users table.

MySQL

SELECT * FROM [1];

Drag options to blanks, or click blank then click option'

Aorders

Buser

Cusers

Dcustomers

Attempts:

3 left

💡 Hint

Common Mistakes

Using singular form 'user' instead of 'users'.

Selecting from unrelated tables like 'orders'.

The table name is users. Using SELECT * FROM users; retrieves all records.

2fill in blank

medium

Complete the code to find users with age greater than 30.

MySQL

SELECT * FROM users WHERE age [1] 30;

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A>

B<

C=

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' which finds ages less than 30.

Using '=' which finds ages exactly 30.

The operator > means 'greater than'. So, age > 30 finds users older than 30.

3fill in blank

hard

Fix the error in the query to count users by city.

MySQL

SELECT city, COUNT(*) AS user_count FROM users GROUP BY [1];

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Aage

Bname

Cuser_count

Dcity

Attempts:

3 left

💡 Hint

Common Mistakes

Grouping by 'age' or 'name' instead of 'city'.

Grouping by the alias 'user_count' which is invalid.

Grouping by city counts users per city. Grouping by other columns won't group correctly.

4fill in blank

hard

Fill both blanks to find users whose name starts with 'A' and order by age descending.

MySQL

SELECT * FROM users WHERE name [1] 'A%' ORDER BY age [2];

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ALIKE

BASC

CDESC

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' instead of LIKE for pattern matching.

Ordering age ascending instead of descending.

Use LIKE 'A%' to find names starting with 'A'. Use ORDER BY age DESC to sort from oldest to youngest.

5fill in blank

hard

Fill all three blanks to create a new table named 'employees' with columns 'id' (integer primary key), 'name' (text), and 'salary' (decimal).

MySQL

CREATE TABLE [1] (id [2] PRIMARY KEY, name [3], salary DECIMAL(10,2));

Drag options to blanks, or click blank then click option'

Aemployees

BINTEGER

CTEXT

DVARCHAR(100)

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong table name.

Using TEXT instead of VARCHAR for name.

Not specifying PRIMARY KEY for id.

The table name is employees. The id column is an INTEGER primary key. The name column is VARCHAR(100) type.