Built-in Jinja context variables in dbt - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access the current model's name using a built-in Jinja variable.

dbt

SELECT * FROM {{ [1].this }}

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

Amodel

Bref

Cthis

Dconfig

Attempts:

3 left

💡 Hint

Common Mistakes

Using model instead of this.

Trying to use ref which is for referencing other models.

The this variable in dbt's Jinja context refers to the current model's full identifier, which can be used to reference the model itself.

2fill in blank

medium

Complete the code to get the current model's schema using a built-in Jinja variable.

dbt

SELECT schema_name FROM information_schema.schemata WHERE schema_name = '{{ [1].schema }}'

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

Aadapter

Btarget

Cconfig

Dthis

Attempts:

3 left

💡 Hint

Common Mistakes

Using target.schema which refers to the target schema for the run, not the model's schema.

Using config.schema which is for configuration settings.

The this.schema variable gives the schema name of the current model in dbt.

3fill in blank

hard

Fix the error in the code to correctly access the current model's alias using a built-in Jinja variable.

dbt

SELECT '{{ [1].alias }}' AS model_alias

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

Athis

Btarget

Cconfig

Dref

Attempts:

3 left

💡 Hint

Common Mistakes

Using target.alias which does not exist.

Using config.alias which is for configuration.

The this.alias variable holds the alias of the current model in dbt.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps each column name to its data type from the current model's columns.

dbt

{ [1]: [2] for col in this.columns }

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

Acol.name

Bcol.data_type

Ccol.type

Dcol.column_name

Attempts:

3 left

💡 Hint

Common Mistakes

Using col.type which is not a valid attribute.

Using col.column_name which is not the correct attribute.

Each column object has a name and data_type attribute. The comprehension maps column names to their data types.

5fill in blank

hard

Fill all three blanks to create a filter that selects columns with data type 'string' and length greater than 10 from the current model's columns.

dbt

{col.name: col.data_type for col in this.columns if col.data_type == '[1]' and col.character_maximum_length [2] [3]

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

Ainteger

B>

C10

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'integer' instead of 'string' for data type.

Using '<' instead of '>' for length comparison.

This comprehension filters columns where the data type is 'string' and the maximum character length is greater than 10.

Practice

1. What does the built-in Jinja context variable run_started_at provide in dbt?

easy

A. The total number of models in the project

B. The name of the current model being executed

C. The timestamp when the current dbt run started

D. The database connection string

Solution

1. Step 1: Understand the purpose of run_started_at

   This variable holds the timestamp marking the start of the dbt run.

2. Step 2: Compare with other options

   Other options describe unrelated information like model name or connection details.

3. Final Answer:

   The timestamp when the current dbt run started -> Option C

4. Quick Check:

   run_started_at = Timestamp [OK]

Hint: Remember: run_started_at = run start time [OK]

Common Mistakes:

• Confusing run_started_at with model name
• Thinking it gives database info
• Assuming it counts models

2. Which of the following is the correct syntax to access the current model name using a built-in Jinja context variable in dbt?

easy

A. {{ this.name }}

B. {{ model_name }}

C. {{ this.model }}

D. {{ current_model }}

Solution

1. Step 1: Recall the correct variable for current model

   The variable this refers to the current model, and this.name gives its name.

2. Step 2: Check syntax correctness

   Only {{ this.name }} correctly accesses the model name in Jinja syntax.

3. Final Answer:

   {{ this.name }} -> Option A

4. Quick Check:

   Current model name = {{ this.name }} [OK]

Hint: Use this.name for current model name [OK]

Common Mistakes:

• Using undefined variables like model_name
• Missing dot notation after this
• Using incorrect variable names

3. Given the following dbt Jinja code snippet, what will be the output of {{ invocation_id }}?

{% set id = invocation_id %}{{ id }}

medium

A. The number of models executed so far

B. A unique identifier string for the current dbt run

C. The current timestamp

D. An error because invocation_id is undefined

Solution

1. Step 1: Understand what invocation_id represents

   This variable holds a unique string ID for the current dbt run invocation.

2. Step 2: Analyze the code snippet

   The code sets id to invocation_id and then outputs it, so it prints the unique run ID.

3. Final Answer:

   A unique identifier string for the current dbt run -> Option B

4. Quick Check:

   invocation_id = Unique run ID [OK]

Hint: invocation_id = unique run ID string [OK]

Common Mistakes:

• Thinking it counts models
• Confusing with timestamps
• Assuming it causes an error

4. You wrote this dbt Jinja code but get an error:

{{ run_started_at.strftime('%Y-%m-%d') }}

. What is the likely cause?

medium

A. run_started_at is a string, not a datetime object, so strftime fails

B. Missing parentheses after run_started_at

C. strftime is not a valid method in Jinja

D. You must use single curly braces instead of double

Solution

1. Step 1: Check the type of run_started_at

   In dbt, run_started_at is a string timestamp, not a datetime object.

2. Step 2: Understand why strftime fails

   Since it's a string, calling strftime (a datetime method) causes an error.

3. Final Answer:

   run_started_at is a string, not a datetime object, so strftime fails -> Option A

4. Quick Check:

   String type blocks datetime methods [OK]

Hint: run_started_at is string; convert before datetime methods [OK]

Common Mistakes:

• Assuming run_started_at is datetime
• Using single braces for Jinja variables
• Thinking strftime is unsupported in Jinja

5. You want to create a dbt model that adds a column with the current run's unique ID and the run start date in 'YYYY-MM-DD' format. Which Jinja code snippet correctly uses built-in context variables to achieve this?

hard

A. {% set run_date = run_started_at.split('-')[0] %}
SELECT *, '{{ invocation_id }}' AS run_id, '{{ run_date }}' AS run_date FROM {{ this }}

B. {% set run_date = run_started_at.strftime('%Y-%m-%d') %}
SELECT *, '{{ invocation_id }}' AS run_id, '{{ run_date }}' AS run_date FROM {{ this }}

C. SELECT *, '{{ invocation_id }}' AS run_id, '{{ run_started_at }}' AS run_date FROM {{ this }}

D. {% set run_date = run_started_at[:10] %}
SELECT *, '{{ invocation_id }}' AS run_id, '{{ run_date }}' AS run_date FROM {{ this }}

Solution

1. Step 1: Extract date from run_started_at string

   Since run_started_at is a string like 'YYYY-MM-DDTHH:MM:SS', slicing the first 10 characters gets the date.

2. Step 2: Use invocation_id and run_date in SELECT

   The snippet correctly sets run_date and uses both variables in the SELECT statement.

3. Step 3: Check other options for errors

   {% set run_date = run_started_at.strftime('%Y-%m-%d') %} SELECT *, '{{ invocation_id }}' AS run_id, '{{ run_date }}' AS run_date FROM {{ this }} tries to use strftime on a string (error). SELECT *, '{{ invocation_id }}' AS run_id, '{{ run_started_at }}' AS run_date FROM {{ this }} uses full timestamp, not formatted date. {% set run_date = run_started_at.split('-')[0] %} SELECT *, '{{ invocation_id }}' AS run_id, '{{ run_date }}' AS run_date FROM {{ this }} extracts only year incorrectly.

4. Final Answer:

   Extracts date with run_started_at[:10] and uses invocation_id -> Option D

5. Quick Check:

   Slice string for date, use invocation_id [OK]

Hint: Slice run_started_at[:10] for date, use invocation_id [OK]

Common Mistakes:

• Using strftime on string variable
• Not formatting run_started_at to date
• Extracting only year instead of full date