DBT Meets Mage: Powering Advanced Data Transformations
Shashank Mishra
Data Engineering
TLDR
When
DBT (Data Build Tool), a renowned data transformation framework, converges with
Mage, it amplifies ETL processes to new heights. This article explores this powerful synergy which facilitates enhanced data modeling, giving businesses a competitive edge. By tapping into this combo, data professionals can supercharge their operations and drive data precision to the forefront.
Outline
Introduction to Mage
Transform DBT with Mage
Set up DBT models & orchestrate DBT runs
Conclusion
Introduction to Mage
In an age where data is the new oil, efficient and reliable data management tools are essential.
Mageis a platform committed to simplifying data integration and analytics. Designed for seamless data transformation and loading, Mage is transforming how businesses approach data management. Here are its key features:
Automated Data Pipeline
: Mage automates data extraction, transformation, and loading (ETL) processes. It can extract data from multiple sources, transform it to a desirable format, and load it into a data warehouse.
Data Connectors
: Mage offers various data connectors to widely-used data sources like Shopify, Facebook Ads, Google Ads, Google Analytics, etc. This makes it easier to import data from these platforms.
Easy Integration
: Mage provides easy integration with popular data warehouses including Google BigQuery, Amazon Redshift, and Snowflake.
Pre-built SQL Models
: Mage comes with pre-built SQL models for popular e-commerce platforms like Shopify and WooCommerce. These models simplify the process of data analysis.
Incremental Loading
: Mage supports incremental loading, which means only new or updated data is loaded into the data warehouse. This saves storage space and improves efficiency.
Data Transformations
: Mage performs automatic data transformations, converting raw data into a more usable format. This process makes the data ready for analysis and reporting.
Scheduled Refresh
: Data refreshes can be scheduled in Mage, ensuring that the data in the warehouse is always up-to-date.
Data Security
: Mage places a high emphasis on data security, ensuring data privacy and compliance with GDPR and other data protection regulations.
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Transform DBT with Mage
By integrating
DBT (Data Build Tool)with
Mage, data transformation reaches new heights of efficiency and precision. This synergy unlocks unparalleled ETL capabilities, setting a new standard in data processing.
Overview
- Build, run, and manage your dbt models with Mage.
Analytics engineers
- With Mage and dbt combined, you can expand, build and run complex data pipelines.
Data engineers
- Simplify your data infrastructure and reduce the amount of redundant tools in your “modern” data stack. Replace dbt cloud and Airflow with Mage’s native integration with dbt.
Features
Schedule dbt model runs
- Trigger your dbt model runs on a regular schedule, from an event, or via API request.
Run specific dbt models and their dependencies
Run all models and optionally exclude others
DBT models can depend on non-dbt related tasks, Examples:
Build model after data ingestion from API
Build model after another pipeline completes
Preview dbt model results as you write SQL
Build dynamic dbt pipelines using flexible variable interpolation, Examples:
{{ env_var('...') }}
{{ variables('...') }}
{{ mage_secret_var('...') }}
Automatically run dbt tests every time a pipeline runs
- Write checks using dbt tests, then Mage will run them and fail the pipeline if the test results produce any failures.
Observability built-in
- Monitor your dbt pipelines and get alerted when things break.
Supported connectors
dbt-bigquery
dbt-core
dbt-postgres
dbt-redshift
dbt-snowflake
dbt-sqlserver
dbt-trino
dbt-spark
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Set up DBT models & orchestrate DBT runs
Configuring
DBT (Data Build Tool)models paves the way for robust data structures, while orchestrating DBT runs ensures seamless, automated workflows in data transformation.
1. Set up new Mage project
b. For the rest of this tutorial, we’ll use the project name
demo_project
.
2. Set up dbt project
a. Create dbt project
i. Open Mage and go to the terminal page:
http://localhost:6789/terminal
ii. Initiate your dbt project using the init command (for this tutorial, we’ll use the dbt project name demo):
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cd demo_project/dbt
dbt init demo -s
touch demo/profiles.yml
For more information on creating a dbt project, read their
documentation3. Create standard pipeline
a. Go to the Mage dashboard and click the button
+ New pipeline
and select the option labeled
Standard (batch)
.
b. Click the
Pipeline settings
icon in the left pane, and change its name to
dbt demo pipeline
, then click the
Save pipeline settings
button.
4. Create dbt profile for database connections
a. On the left side of the page in the file browser, expand the folder
demo_project/dbt/demo/
b. Click the file named
profiles.yml
c. Paste the following credentials in that file:
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demo:
target: dev
outputs:
dev:
dbname: xyleviup
host: queenie.db.elephantsql.com
password: edSrMWH7Mww-lTKpp-jPHX9sYSNLy7LG
port: 5432
schema: dbt_demo
type: postgres
user: xyleviup
d. Save the
profiles.yml
file by pressing
Command (⌘) + S
.
e. Close the file by pressing the
X
button on the right side of the file name
dbt/demo/profiles.yml
5. Add data loader block to pipeline
a. Click the
+ Data loader
button, select
Python
, then click
API
.
b. In the popup dialog
Data loader block name
, change its name to
load data
, then click the
Save and add block
button.
c. Paste the following code in that block:
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import io
import pandas as pd
import requests
from pandas import DataFrame
@data_loader
def load_data_from_api(**kwargs) -> DataFrame:
url = 'https://raw.githubusercontent.com/mage-ai/datasets/master/restaurant_user_transactions.csv'
response = requests.get(url)
df = pd.read_csv(io.StringIO(response.text), sep=',')
df.columns = ['_'.join(col.split(' ')) for col in df.columns]
return df
6. Add dbt model block to pipeline
a. Under the data loader block you just added, click the button
dbt model
, then click the option
Single model
.
b. In the file browser that pops up, click the file named
my_second_dbt_model.sql
under the folders
demo/models/example/
i. This will add 2 dbt blocks to your pipeline: 1 for the dbt model named
my_first_dbt_model
and the 2nd for the dbt model named
my_second_dbt_model
.
ii. The model named
my_first_dbt_model
was added to the pipeline because
my_second_dbt_model
references it.
7. Edit dbt model my_first_dbt_model
a. In the dbt block named
my_first_dbt_model
, next to the label
Target
at the top, choose
dev
in the dropdown list. You can also check
Manually enter
target
, and enter
dev
in the input field.
b. Paste the following SQL into the dbt model named
my_first_dbt_model
:
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WITH source_data AS (
SELECT 1 AS id
UNION ALL
SELECT 2 AS id
)
SELECT *
FROM source_data
c. Run the dbt model block by pressing the play button on the top right of the block or by pressing
Command
+
Enter
.
d. You should see a preview of the query execution logs. To see the query results, click the
Expand table
link at the bottom right corner.
e. After previewing the results, in the top right corner of the block, click on the triple dots to reveal a dropdown menu.
f. Under the dropdown menu, click the option Run model. This command will execute the
dbt run
command and create the table in your data source.
8. Edit dbt model my_second_dbt_model
a. In the dbt block named
my_second_dbt_model
, next to the label Target at the top, choose
dev
in the dropdown list. You can also check
Manually enter target
, and enter
dev
in the input field.
b. Paste the following SQL into the dbt model named
my_second_dbt_model
:
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SELECT
a.*
, b.*
FROM {{ ref('my_first_dbt_model') }} AS a
LEFT JOIN {{ source('mage_demo', 'dbt_demo_pipeline_load_data') }} AS b
ON 1 = 1
WHERE a.id = 1
When a dbt model depends on an upstream block that isn’t a dbt model, a source for that block is automatically added to the
demo_project/dbt/demo/models/example/mage_sources.yml
file.
c. Run the dbt model block by pressing the play button on the top right of the block or by pressing
Command + Enter
.
d. You should see a preview of the query execution logs. To see the query results, click the
Expand table
link at the bottom right corner.
9. Add test for dbt model
a. On the right side of the screen, click the tab labeled
Terminal
.
b. Create a new dbt test file by running the following command:
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touch demo_project/dbt/demo/tests/test_my_second_dbt_model.sql
c. On the left side of the page in the file browser, expand the folder
demo_project/dbt/demo/tests/
and click the file named
test_my_second_dbt_model.sql.
If you don’t see it, refresh the page.
d. Paste the following SQL in the file:
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SELECT id
FROM {{ ref('my_second_dbt_model') }}
GROUP BY id
HAVING (id = 0)
10. Execute pipeline end-to-end
a. Click the name of the pipeline in the header breadcrumbs to go back to the detail page.
b. Create a new trigger with a type
Schedule
and a Frequency
once
. For more details, follow these
steps.
c. After your trigger is created, click the
Start trigger
button at the top of the page.
d. The pipeline will eventually fail because a dbt test failed. This means everything is working as expected.
e. Open the file
demo_project/dbt/demo/models/example/schema.yml
and remove the tests named
unique
under both models. Your file should look like this:
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version: 2
models:
- name: my_first_dbt_model
description: "A starter dbt model"
columns:
- name: id
description: "The primary key for this table"
tests:
- not_null
- name: my_second_dbt_model
description: "A starter dbt model"
columns:
- name: id
description: "The primary key for this table"
tests:
- not_null
f. Click on the
Failed
button next to the pipeline run and click
Retry run
. It should complete running successfully after a few minutes.
Congratulations
! You’ve created a data pipeline that orchestrates your dbt models.
(Source:
Conclusion
In the evolving landscape of data processing, the fusion of
DBT (Data Build Tool)and
Magesignifies a transformative leap. By integrating DBT's modeling prowess with Mage's advanced ETL capabilities, businesses are now better equipped to harness the full potential of their data. As we've explored, from setup to orchestration, this synergy not only streamlines operations but also enhances the precision of data outcomes. As data continues to be an invaluable asset, leveraging such powerful tools becomes imperative for any data-driven enterprise.
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