Documenting models in YAML in dbt - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a model description in YAML.

dbt

models:
  - name: customers
    description: [1]

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

Acustomer_data

B"This model contains customer data"

Ccustomers_table

Dmodel_description

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes around the description string.

Using a variable name instead of a description.

The description field should be a string describing the model. Option B provides a clear description in quotes.

2fill in blank

medium

Complete the code to add a column description in the model YAML.

dbt

models:
  - name: orders
    columns:
      - name: order_id
        description: [1]

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

Aid_order

Border_identifier

C"Unique identifier for each order"

Dorder_id

Attempts:

3 left

💡 Hint

Common Mistakes

Using the column name as the description.

Leaving the description empty.

The description should explain the column's purpose clearly. Option C is a proper description.

3fill in blank

hard

Fix the error in the YAML snippet by completing the description field correctly.

dbt

models:
  - name: products
    description: [1]

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

AList of products

B"List of products

CList of products"

D"List of products"

Attempts:

3 left

💡 Hint

Common Mistakes

Using unmatched quotes causing YAML parsing errors.

Not quoting strings with spaces.

YAML strings should be enclosed in matching quotes. Option D correctly uses matching double quotes.

4fill in blank

hard

Fill both blanks to add a model and a column description in YAML.

dbt

models:
  - name: [1]
    columns:
      - name: [2]
        description: "Customer's email address"

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

Acustomers

Bemail

Corders

Dorder_date

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing model and column names incorrectly.

Using unrelated names that don't match the description.

The model name is 'customers' and the column name is 'email' matching the description.

5fill in blank

hard

Fill all three blanks to document a model with two columns and their descriptions in YAML.

dbt

models:
  - name: [1]
    description: "Sales data model"
    columns:
      - name: [2]
        description: "Unique sale identifier"
      - name: [3]
        description: "Date of the sale"

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

Asales

Bsale_id

Csale_date

Dcustomer_id

Attempts:

3 left

💡 Hint

Common Mistakes

Using column names that don't match the descriptions.

Confusing customer_id with sale_id or sale_date.

The model is 'sales' with columns 'sale_id' and 'sale_date' matching the descriptions.

Practice

1. What is the main purpose of documenting models in YAML in a dbt project?

easy

A. To write SQL queries inside YAML files

B. To execute dbt models automatically

C. To add clear descriptions for models and columns to improve understanding

D. To store raw data files

Solution

1. Step 1: Understand the role of YAML documentation

   YAML files in dbt are used to add metadata like descriptions, not to run code or store data.

2. Step 2: Identify the benefit of documentation

   Adding descriptions for models and columns helps team members understand the data and maintain the project easily.

3. Final Answer:

   To add clear descriptions for models and columns to improve understanding -> Option C

4. Quick Check:

   Documentation purpose = Add descriptions [OK]

Hint: Documentation in YAML means adding descriptions, not code [OK]

Common Mistakes:

• Thinking YAML runs SQL code
• Confusing YAML with data storage
• Ignoring the importance of descriptions

2. Which of the following is the correct way to start documenting a model named orders in a YAML file?

easy

A. models:
orders
description: 'Contains order details'

B. model:
name: orders
description: 'Contains order details'

C. models:
- orders:
description: 'Contains order details'

D. models:
- name: orders
description: 'Contains order details'

Solution

1. Step 1: Recall YAML syntax for dbt model documentation

   dbt expects a list under models: with each model as a dictionary containing name and description.

2. Step 2: Match the correct structure

   models: - name: orders description: 'Contains order details' correctly uses a list with a dictionary having name and description. Other options misuse keys or structure.

3. Final Answer:

   models: - name: orders description: 'Contains order details' -> Option D

4. Quick Check:

   Model list with name and description = models: - name: orders description: 'Contains order details' [OK]

Hint: Use dash (-) for list items under models in YAML [OK]

Common Mistakes:

• Using singular 'model' instead of 'models'
• Not using dash for list items
• Incorrect indentation or key names

3. Given this YAML snippet documenting a model and its columns:

models:
  - name: customers
    description: 'Customer information'
    columns:
      - name: id
        description: 'Unique customer ID'
      - name: email
        description: 'Customer email address'

What will dbt show as the description for the email column?

medium

A. Unique customer ID

B. Customer email address

C. Customer information

D. No description

Solution

1. Step 1: Locate the column description in YAML

   The email column is listed under columns with its own description key.

2. Step 2: Identify the description text for the email column

   The description for email is 'Customer email address', which dbt will display for that column.

3. Final Answer:

   Customer email address -> Option B

4. Quick Check:

   Column description matches YAML text [OK]

Hint: Column descriptions are under columns > name in YAML [OK]

Common Mistakes:

• Confusing model description with column description
• Missing indentation causing YAML parsing errors
• Assuming no description if not repeated

4. You wrote this YAML to document a model but dbt throws an error:

models:
  - name: sales
    description: 'Sales data'
    columns:
      name: amount
      description: 'Sale amount'

What is the error in this YAML?

medium

A. Missing dash (-) before column name and description

B. Incorrect model name key

C. Description should be under models, not columns

D. YAML does not support nested lists

Solution

1. Step 1: Check YAML list syntax for columns

   Each column should be a list item with a dash (-) before its dictionary of keys.

2. Step 2: Identify missing dash in columns

   The name and description keys under columns lack the dash, so YAML treats them as keys of columns instead of list items.

3. Final Answer:

   Missing dash (-) before column name and description -> Option A

4. Quick Check:

   List items need dash (-) in YAML [OK]

Hint: Use dash (-) before each column in columns list [OK]

Common Mistakes:

• Forgetting dash for list items
• Misplacing description keys
• Confusing YAML lists and dictionaries

5. You want to document two models, users and transactions, each with columns and descriptions. Which YAML structure correctly documents both models with their columns?

hard

A. models:
- name: users
description: 'User data'
columns:
- name: user_id
description: 'User identifier'
- name: transactions
description: 'Transaction data'
columns:
- name: transaction_id
description: 'Transaction identifier'

B. models:
users:
description: 'User data'
columns:
user_id: 'User identifier'
transactions:
description: 'Transaction data'
columns:
transaction_id: 'Transaction identifier'

C. models:
- users:
description: 'User data'
columns:
- user_id: 'User identifier'
- transactions:
description: 'Transaction data'
columns:
- transaction_id: 'Transaction identifier'

D. models:
name: users
description: 'User data'
columns:
- name: user_id
description: 'User identifier'
name: transactions
description: 'Transaction data'
columns:
- name: transaction_id
description: 'Transaction identifier'

Solution

1. Step 1: Understand YAML list structure for multiple models

   dbt expects models as a list of dictionaries, each with name, description, and columns as a list.

2. Step 2: Evaluate each option's structure

   models: - name: users description: 'User data' columns: - name: user_id description: 'User identifier' - name: transactions description: 'Transaction data' columns: - name: transaction_id description: 'Transaction identifier' correctly uses a list with two model dictionaries, each with proper keys and column lists. The other options misuse keys or structure. models: name: users description: 'User data' columns: - name: user_id description: 'User identifier' name: transactions description: 'Transaction data' columns: - name: transaction_id description: 'Transaction identifier' repeats keys incorrectly.

3. Final Answer:

   models: - name: users description: 'User data' columns: - name: user_id description: 'User identifier' - name: transactions description: 'Transaction data' columns: - name: transaction_id description: 'Transaction identifier' -> Option A

4. Quick Check:

   Multiple models as list items with name and columns = models: - name: users description: 'User data' columns: - name: user_id description: 'User identifier' - name: transactions description: 'Transaction data' columns: - name: transaction_id description: 'Transaction identifier' [OK]

Hint: List each model with dash (-) and include columns as lists [OK]

Common Mistakes:

• Using model names as keys instead of list items
• Repeating keys at same level
• Not using dash for multiple models