Query interface basics in Ruby on Rails - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to fetch all users from the database.

Ruby on Rails

users = User.[1]

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

Aselect

Bfind

Cwhere

Dall

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'find' without an ID causes an error.

Using 'where' requires conditions.

Using 'select' is for choosing columns, not records.

The all method fetches all records from the users table.

2fill in blank

medium

Complete the code to find users with the name 'Alice'.

Ruby on Rails

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

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

A'Alice'

B:Alice

CAlice

D"Alice"

Attempts:

3 left

💡 Hint

Common Mistakes

Using a symbol (:Alice) instead of a string.

Not quoting the string at all.

Using bare words without quotes.

In Rails queries, string values must be quoted with single or double quotes. Here, 'Alice' is correct.

3fill in blank

hard

Fix the error in the code to get the first user ordered by created_at.

Ruby on Rails

user = User.order(:created_at).[1]

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

Alast

Bfirst

Ctake

Dfind

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'last' returns the newest record, not the first.

Using 'find' requires an ID argument.

Using 'take' returns an array, while 'first' returns a single record.

The first method returns the first record in the ordered list.

4fill in blank

hard

Fill both blanks to get users created after 2023-01-01 and order by name.

Ruby on Rails

users = User.where("created_at > [1]").[2](:name)

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

A'2023-01-01'

Border

Csort

Dwhere

Attempts:

3 left

💡 Hint

Common Mistakes

Using sort instead of order.

Not quoting the date string.

Using where again instead of order.

The date must be a string in quotes. The order method sorts the results by the given column.

5fill in blank

hard

Fill all three blanks to select users with age over 30, order by age descending, and limit to 5 results.

Ruby on Rails

users = User.where('age [1] [2]').order(age: [3]).limit(5)

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

A>

B30

C:desc

D:asc

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' for age.

Ordering ascending instead of descending.

Quoting the number 30 in the where clause.

The query filters users older than 30 using '>'. The order is descending with :desc.