dbt-date for date spine - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select the date column from the date spine model.

dbt

SELECT [1] FROM {{ ref('date_spine') }}

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

Auser_id

Bdate

Ccreated_at

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting a column that does not exist in the date spine model.

Using a column related to users instead of dates.

The date spine model contains a 'date' column representing each date in the range.

2fill in blank

medium

Complete the code to generate a date spine from 2023-01-01 to 2023-01-10 using dbt-date.

dbt

SELECT * FROM {{ dbt_utils.date_spine('day', '2023-01-01', [1]) }}

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

A'2023-01-10'

B'2023-01-05'

C'2023-01-15'

D'2023-01-20'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a date outside the desired range.

Confusing start and end dates.

The date spine should cover dates up to '2023-01-10' as specified.

3fill in blank

hard

Fix the error in the code to correctly generate a date spine for months from 2023-01-01 to 2023-03-01.

dbt

SELECT * FROM {{ dbt_utils.date_spine([1], '2023-01-01', '2023-03-01') }}

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

A'year'

B'day'

C'month'

D'week'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'day' instead of 'month' for monthly spine.

Using an invalid grain string.

To generate a monthly date spine, the grain must be 'month'.

4fill in blank

hard

Fill both blanks to create a date spine for weeks from 2023-01-01 to 2023-02-01 and select the date column.

dbt

WITH spine AS (
  SELECT * FROM {{ dbt_utils.date_spine([1], [2], '2023-02-01') }}
)
SELECT date FROM spine

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

A'week'

B'2023-01-01'

C'2023-01-15'

D'2023-01-31'

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping start and end dates.

Using wrong grain like 'day' for weekly spine.

The grain is 'week' and the start date is '2023-01-01' to cover weeks starting from that date.

5fill in blank

hard

Fill all three blanks to create a date spine for days from 2023-01-01 to 2023-01-07, select the date, and filter dates after 2023-01-03.

dbt

WITH spine AS (
  SELECT * FROM {{ dbt_utils.date_spine([1], [2], [3]) }}
)
SELECT date FROM spine WHERE date > '2023-01-03'

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

A'day'

B'2023-01-01'

C'2023-01-07'

D'2023-01-05'

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect date range.

Using wrong grain like 'month' for daily spine.

The grain is 'day', start date '2023-01-01', and end date '2023-01-07' to cover the desired range.

Practice

1. What is the main purpose of using dbt-date to create a date spine in a data model?

easy

A. To join tables based on user IDs

B. To filter out invalid dates from data

C. To generate a continuous list of dates for analysis

D. To calculate the sum of sales values

Solution

1. Step 1: Understand the concept of a date spine

   A date spine is a continuous list of dates covering a range, used to ensure consistent date coverage in analysis.

2. Step 2: Identify the purpose of dbt-date

   dbt-date helps create this continuous list of dates automatically for use in data models.

3. Final Answer:

   To generate a continuous list of dates for analysis -> Option C

4. Quick Check:

   Date spine = continuous dates list [OK]

Hint: Date spine means continuous dates, not filtering or sums [OK]

Common Mistakes:

• Confusing date spine with filtering data
• Thinking it calculates aggregates
• Assuming it joins unrelated tables

2. Which of the following is the correct syntax to create a date spine using dbt-date with a start date of '2023-01-01' and end date of '2023-01-05'?

easy

A. select * from dbt_date.spine('2023-01-01', '2023-01-05')

B. select * from dbt_date.spine(date_start = '2023-01-01', date_end = '2023-01-05')

C. select * from dbt_date.spine(start => '2023-01-01', finish => '2023-01-05')

D. select * from dbt_date.spine(start_date => '2023-01-01', end_date => '2023-01-05')

Solution

1. Step 1: Recall dbt-date spine function syntax

   The correct syntax uses named parameters start_date and end_date with => to assign values.

2. Step 2: Compare options to syntax

   select * from dbt_date.spine(start_date => '2023-01-01', end_date => '2023-01-05') matches the correct named parameter style. Others use incorrect parameter names or assignment styles.

3. Final Answer:

   select * from dbt_date.spine(start_date => '2023-01-01', end_date => '2023-01-05') -> Option D

4. Quick Check:

   Named params with => = select * from dbt_date.spine(start_date => '2023-01-01', end_date => '2023-01-05') [OK]

Hint: Use named params with => for dbt-date spine [OK]

Common Mistakes:

• Using positional parameters instead of named
• Wrong parameter names like start or finish
• Using = instead of => for assignment

3. Given the following dbt model code snippet, what will be the output rows for the date spine?

select * from dbt_date.spine(start_date => '2023-01-01', end_date => '2023-01-03')

medium

A. [{'date': '2023-01-01'}, {'date': '2023-01-02'}, {'date': '2023-01-03'}]

B. [{'date': '2023-01-01'}, {'date': '2023-01-03'}]

C. [{'date': '2023-01-02'}]

D. Empty result set

Solution

1. Step 1: Understand the date range in the spine

   The spine includes all dates from start_date to end_date inclusive, so from 2023-01-01 to 2023-01-03.

2. Step 2: List all dates in the range

   The dates are 2023-01-01, 2023-01-02, and 2023-01-03, each as a separate row.

3. Final Answer:

   [{'date': '2023-01-01'}, {'date': '2023-01-02'}, {'date': '2023-01-03'}] -> Option A

4. Quick Check:

   Date spine includes all dates in range [OK]

Hint: Date spine includes every date from start to end [OK]

Common Mistakes:

• Skipping dates between start and end
• Only returning start and end dates
• Expecting empty results for valid range

4. You wrote this dbt model to create a date spine:

select * from dbt_date.spine(start_date => '2023-01-01', end_date => '2023-01-05', datepart => 'month')

But the output only shows one date: '2023-01-01'. What is the likely error?

medium

A. The end_date is before the start_date

B. Using 'month' for datepart returns only the first date of the month

C. The function requires datepart to be 'day' to generate daily dates

D. The syntax for start_date is incorrect

Solution

1. Step 1: Understand the effect of datepart = 'month'

   Setting datepart to 'month' generates one date per month, usually the first day of each month.

2. Step 2: Analyze why only one date appears

   Since the range is within January 2023, only the first day of January is returned.

3. Final Answer:

   Using 'month' for datepart returns only the first date of the month -> Option B

4. Quick Check:

   datepart 'month' = first day only [OK]

Hint: datepart 'month' returns one date per month, not daily [OK]

Common Mistakes:

• Assuming datepart 'month' returns all days
• Thinking end_date is invalid
• Believing syntax error caused issue

5. You want to create a date spine that includes every Monday between '2023-01-01' and '2023-01-31' using dbt-date. Which approach correctly achieves this?

hard

A. Set datepart = 'day' and filter dates where extract(dow from date) = 1 (Monday)

B. Use datepart = 'week' and filter the spine for dates where extract(dow from date) = 1 (Monday)

C. Set datepart = 'month' and filter for Mondays

D. Use datepart = 'day' without filtering, then manually select Mondays later

Solution

1. Step 1: Understand datepart options

   datepart = 'day' generates every day in the range, allowing filtering by weekday.

2. Step 2: Filter for Mondays

   Extracting day of week (dow) and selecting where dow = 1 (Monday) filters the daily spine to only Mondays.

3. Step 3: Why not 'week' or 'month'

   datepart = 'week' returns one date per week (usually Sunday), so filtering for Monday won't work. 'month' returns one date per month.

4. Final Answer:

   Set datepart = 'day' and filter dates where extract(dow from date) = 1 (Monday) -> Option A

5. Quick Check:

   Daily spine + filter Monday = Set datepart = 'day' and filter dates where extract(dow from date) = 1 (Monday) [OK]

Hint: Generate daily spine, then filter Mondays by weekday [OK]

Common Mistakes:

• Using datepart 'week' expecting Mondays
• Using 'month' which returns too few dates
• Not filtering after generating spine