Configuring sources in YAML in dbt - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a source name in YAML.

dbt

sources:
  - name: [1]

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

Amy_source

Bsource_name

Cdata_source

Dtable_source

Attempts:

3 left

💡 Hint

Common Mistakes

Using spaces in the source name

Omitting the source name

Using invalid characters in the name

The name field defines the source name. Here, my_source is a valid source name.

2fill in blank

medium

Complete the code to specify the database for the source.

dbt

sources:
  - name: my_source
    [1]: analytics_db

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

Aschema

Bdatabase

Ctable

Dalias

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing schema with database

Omitting the database key

Using an incorrect key name

The database key specifies the database where the source tables reside.

3fill in blank

hard

Fix the error in the source table definition by completing the missing key.

dbt

sources:
  - name: my_source
    database: analytics_db
    tables:
      - [1]: users

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

Aname

Btable

Csource_table

Dtable_name

Attempts:

3 left

💡 Hint

Common Mistakes

Using table_name instead of name

Using table as the key

Omitting the table name key

The correct key to define a table inside tables is name.

4fill in blank

hard

Fill both blanks to define a source with a schema and a table name.

dbt

sources:
  - name: my_source
    database: analytics_db
    [1]: public
    tables:
      - name: [2]

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

Aschema

Busers

Ctable

Ddatabase

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up database and schema

Using table instead of name for the table

Omitting the schema key

The schema key defines the schema name, and users is the table name.

5fill in blank

hard

Fill all three blanks to define a source with database, schema, and a table with an alias.

dbt

sources:
  - name: my_source
    [1]: analytics_db
    [2]: sales
    tables:
      - name: orders
        [3]: sales_orders

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

Adatabase

Bschema

Calias

Dtable

Attempts:

3 left

💡 Hint

Common Mistakes

Using table instead of alias for renaming

Mixing up schema and database keys

Omitting the alias key when renaming

The database and schema keys specify where the source lives. The alias key gives the table a different name in dbt.

Practice

1. What is the main purpose of configuring sources in a dbt YAML file?

easy

A. To write SQL queries for data transformation

B. To tell dbt where to find raw data tables

C. To create dashboards for data visualization

D. To schedule dbt runs automatically

Solution

1. Step 1: Understand the role of source configuration

   Source configuration in dbt YAML files defines where raw data tables are located in the database.

2. Step 2: Differentiate from other dbt tasks

   Writing SQL queries and scheduling runs are done elsewhere, not in source YAML files.

3. Final Answer:

   To tell dbt where to find raw data tables -> Option B

4. Quick Check:

   Source config = raw data location [OK]

Hint: Sources define raw table locations in YAML [OK]

Common Mistakes:

• Confusing source config with SQL model code
• Thinking sources schedule runs
• Assuming sources create visualizations

2. Which of the following is the correct syntax to define a source in a dbt YAML file?

easy

A. source:
name: raw_data
table:
- customers

B. sources:
name: raw_data
tables:
- customers

C. sources:
- name: raw_data
tables:
- name: customers

D. source:
- raw_data:
tables:
- customers

Solution

1. Step 1: Recall correct YAML source structure

   The correct syntax uses 'sources' as a list with 'name' and nested 'tables' list, each with a 'name'.

2. Step 2: Compare options to syntax

   sources: - name: raw_data tables: - name: customers matches the correct indentation and keys exactly.

3. Final Answer:

   sources: - name: raw_data tables: - name: customers -> Option C

4. Quick Check:

   Correct YAML keys and indentation = sources: - name: raw_data tables: - name: customers [OK]

Hint: Look for 'sources' list with 'name' and 'tables' keys [OK]

Common Mistakes:

• Using singular 'source' instead of 'sources'
• Missing 'name' key for tables
• Incorrect indentation breaking YAML structure

3. Given this YAML snippet, what is the value of the 'loaded_at_field' for the source 'sales_data'?

sources:
  - name: sales_data
    tables:
      - name: transactions
        loaded_at_field: transaction_date

medium

A. transaction_date

B. transactions

C. loaded_at_field

D. sales_data

Solution

1. Step 1: Locate the 'loaded_at_field' key in YAML

   It is nested under the 'transactions' table inside the 'sales_data' source.

2. Step 2: Identify the value assigned

   The value assigned to 'loaded_at_field' is 'transaction_date'.

3. Final Answer:

   transaction_date -> Option A

4. Quick Check:

   loaded_at_field value = transaction_date [OK]

Hint: Find 'loaded_at_field' key's value under table [OK]

Common Mistakes:

• Confusing source name with field value
• Picking table name instead of field value
• Misreading YAML indentation levels

4. Identify the error in this source configuration YAML:

sources:
  - name: marketing_data
    tables:
      - name: leads
        freshness:
          warn_after:
            count: 12
            period: hours
          error_after:
            count: 1
            period: days

medium

A. 'warn_after' and 'error_after' counts are reversed

B. The indentation under 'freshness' is incorrect

C. The 'error_after' period should be less than 'warn_after'

D. The 'period' values must be singular strings

Solution

1. Step 1: Understand dbt freshness period syntax

   dbt freshness requires singular 'period' values like 'hour', 'day', 'minute'. Plural forms ('hours', 'days') are invalid and cause errors.

2. Step 2: Check the YAML periods

   'period: hours' and 'period: days' use plural, which dbt does not recognize.

3. Step 3: Rule out other options

   A: Counts logical (12 hours warn before 1 day/24 hours error). B: Indentation correct. C: Incorrect--error_after time must be *longer* than warn_after.

4. Final Answer:

   The 'period' values must be singular strings -> Option D

5. Quick Check:

   period: hour/day (singular only) [OK]

Hint: dbt freshness periods must be singular (hour, day) [OK]

Common Mistakes:

• Using plural periods ('hours', 'days')
• Incorrect YAML indentation
• Thinking error_after time should be shorter than warn_after

5. You want to add a test to ensure the 'email' column in the 'users' table source is never null. Which YAML snippet correctly adds this test?

hard

A. sources:
- name: app_data
tables:
- name: users
columns:
- name: email
tests:
- not_null

B. sources:
- name: app_data
tables:
- name: users
tests:
- column: email
test: not_null

C. sources:
- name: app_data
tables:
- users:
columns:
- email:
tests:
- not_null

D. sources:
- name: app_data
tables:
- name: users
columns:
- email
test: not_null

Solution

1. Step 1: Recall correct test syntax in source YAML

   Tests are added under 'columns' with 'name' and a 'tests' list containing test names.

2. Step 2: Check each option's structure

   sources: - name: app_data tables: - name: users columns: - name: email tests: - not_null correctly uses 'columns' list with 'name' and 'tests' list containing 'not_null'.

3. Step 3: Identify errors in other options

   sources: - name: app_data tables: - name: users tests: - column: email test: not_null uses wrong keys, sources: - name: app_data tables: - users: columns: - email: tests: - not_null has wrong nesting, sources: - name: app_data tables: - name: users columns: - email test: not_null uses 'test' instead of 'tests'.

4. Final Answer:

   sources: - name: app_data tables: - name: users columns: - name: email tests: - not_null -> Option A

5. Quick Check:

   Tests under columns with 'tests' list = sources: - name: app_data tables: - name: users columns: - name: email tests: - not_null [OK]

Hint: Tests go under columns with 'tests' list [OK]

Common Mistakes:

• Using 'test' instead of 'tests'
• Wrong nesting of columns and tests
• Misnaming keys like 'column' instead of 'name'