Skip to main content

Creating a date dimension in dbt and Snowflake

A lot of the data that I am working with doesn't lend itself to creating complex star schemas (more on data modelling in a later post) however I want to try and at least want to go to some effort. The one thing that pretty much all my tables have in common is date, so I want to build a date dimension. My strength training happens on a day, my running and walking, parkrun and hopefully the weather data I intend to integrate will have a date on it. This means if I have a date dimension and I aggregate my various facts at date level I can use them together in a single visualisation. 

There are various methods I could have used to create the date dimension and I went with using the dbt spine, this was really simple using the utilities: 


{{ config (
materialized="view"
)}}
{{ dbt_utils.date_spine(
datepart="day",
start_date="cast('2024-01-01' as date)",
end_date="cast('2025-01-01' as date)"
)
}}
view raw dbtdatesall.sql hosted with ❤ by GitHub

Used the date functions in Snowflake to extract relevant fields such as year, month, day in words and year month etc. 

{{ config (
materialized="table"
)}}
select date_day,
year(date_day) date_year,
month(date_day) date_month,
quarter(date_day) date_quarter,
DAYOFWEEK( date_day ) day_of_week,
DAYOFYEAR( date_day ) day_of_year,
WEEK( date_day ) week_of_day,
DAYNAME( date_day ) day_name,
date_day -1 lag_date_1,
year(date_day)*100+ lpad(month(date_day),2,'0') year_month
FROM
{{ source('exercise_data', 'ALL_DATES') }}
view raw datedimSnowfale.sql hosted with ❤ by GitHub

Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

AWS training cloud academy free course

One of the things I like about this course are the instructors are really clear but also that it provides free labs that allow you to actually sign into AWS and perform some actions to actually create and do things without worrying that you are going to incur a cost.  Today I complete one of the hands on labs.  This was to create a lambda function, in this case it was a very basic python script that was searching a website for a keyword. I then placed this into a schedule and used cloudwatch to create a dashboard that monitored the running of this function. Overall it was a very simple use case but it was also a very simple process to setup.  I don't have much to add to this other than it is well worth signing up to cloud academy for the free training if nothing else, I am tempted, once i have done some more training, to give the paid for option a go to get the full sandboxes. 
Post a Comment
Read more

AI News

Here’s a concise roundup of the latest AI news from the past couple of days: AI Technology: Friend or Foe? Researchers and experts continue to debate the impact of artificial intelligence. Is it a boon or a threat? The discussion ranges from AI ethics to its potential in various fields. Read more here . 5 Ways Artificial Intelligence Will Change the World by 2050 Futurists predict that AI will revolutionize our lives in the coming decades. From healthcare to transportation, AI is set to transform industries. Explore the possibilities here . How AI Will Transform Businesses in 2023 Business leaders are embracing AI to enhance efficiency, decision-making, and customer experiences. Stay updated on the latest AI trends in the corporate world here . China’s High-Level AI Modules China is pushing the boundaries of AI with modular next-generation systems. These high-level AI technologies promise breakthroughs in fields like robotics, healthcare, and smart cities. Learn more here . The Future ...
Post a Comment
Read more

Data Cleansing View in Snowflake

For part of one of my free ETLs I am using Zapps to transfer e-mails from Google Sheets and then Keboola to transfer the sheets into my Snowflake database. I am familiar with string searches and cleansing in Oracle and using python but have not had the chance to do this in Snowflake. I wanted to give it a go as a proof of concept if nothing else. There were some difference in functions between Oracle and Snowflake, no INSTR and using POSITION instead and some difference in working with dates / timestamps but overall it was very similar.  The code below is what I ended up using:  I think want to use this to create some overview graphics to allow me to track the success or failure of my ETLs. Assuming the aspects of Retool remain free you can see how much ETL is going on this link .  In case things aren't working, here is a table of the output I am producing. 
Post a Comment
Read more