Why query interface abstracts SQL in Ruby on Rails - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to fetch all users from the database using ActiveRecord.

Ruby on Rails

users = User.[1]

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

Aall

Bselect

Cget

Dfetch

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'fetch' or 'get' which are not ActiveRecord methods for fetching all records.

The all method fetches all records from the users table using ActiveRecord's query interface.

2fill in blank

medium

Complete the code to find users with age greater than 30 using ActiveRecord query interface.

Ruby on Rails

users = User.where("age [1] ?", 30)

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

A>

B<

C=

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' or '=' which would select wrong users.

The where method uses SQL conditions. To find users older than 30, use the '>' operator.

3fill in blank

hard

Fix the error in the code to order users by name ascending.

Ruby on Rails

users = User.order(name: [1])

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

A:desc

Bname

C:asc

Dorder

Attempts:

3 left

💡 Hint

Common Mistakes

Using ':desc' which orders descending.

Passing a string instead of a symbol.

The order method accepts :asc or :desc symbols to specify ascending or descending order. Use :asc for ascending.

4fill in blank

hard

Fill both blanks to select users with name starting with 'A' and order by age descending.

Ruby on Rails

users = User.where("name [1] ?", 'A%').order('age [2]')

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

ALIKE

BASC

CDESC

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' instead of 'LIKE' for pattern matching.

Ordering ascending instead of descending.

Use LIKE to match names starting with 'A'. Use DESC to order age descending.

5fill in blank

hard

Fill all three blanks to create a hash mapping user emails to their names for users older than 25.

Ruby on Rails

result = User.where("age [1] ?", 25).pluck([2], [3]).to_h

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

A>

B:email

C:name

D:age

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' or '=' for age filter.

Plucking wrong columns like age instead of email or name.

Use '>' to filter users older than 25. pluck extracts email and name columns. to_h converts array pairs to a hash.