Environment<\/strong>: A cloud or on-premises data platform with access to CI\/CD pipelines.<\/li>\n<\/ul>\n\n\n\nHands-on: Step-by-Step Beginner-Friendly Setup Guide<\/h3>\n\n\n\n
This guide demonstrates setting up a data contract using dbt and Great Expectations for a simple orders<\/code> table.<\/p>\n\n\n\n\n- Set Up dbt Project<\/strong>:\n
\n- Install dbt:
pip install dbt-core dbt-snowflake<\/code> (assuming Snowflake as the data platform).<\/li>\n\n\n\n- Initialize a dbt project:
dbt init my_project<\/code>.<\/li>\n\n\n\n- Configure
profiles.yml<\/code> for your data warehouse connection.<\/li>\n<\/ul>\n<\/li>\n\n\n\n- Define the Data Contract<\/strong>:
- Create a YAML file in
models\/schema.yml<\/code> to define the contract.<\/li><\/ul><\/li>\n<\/ol>\n\n\n\nversion: 2\nmodels:\n - name: orders\n config:\n materialized: table\n contract:\n enforced: true\n columns:\n - name: order_id\n data_type: string\n constraints:\n - type: not_null\n - type: unique\n description: \"Unique identifier for the order\"\n - name: order_date\n data_type: timestamp\n constraints:\n - type: not_null\n description: \"Date the order was placed\"\n - name: customer_id\n data_type: string\n constraints:\n - type: not_null\n description: \"Unique customer identifier\"\n tests:\n - dbt_utils.recency:\n field: order_date\n datepart: day\n interval: 1<\/code><\/pre>\n\n\n\n2. Define the Data Contract<\/strong>:<\/p>\n\n\n\n\n- Create a YAML file in models\/schema.yml to define the contract.<\/li>\n<\/ul>\n\n\n\n
version: 2\nmodels:\n - name: orders\n config:\n materialized: table\n contract:\n enforced: true\n columns:\n - name: order_id\n data_type: string\n constraints:\n - type: not_null\n - type: unique\n description: \"Unique identifier for the order\"\n - name: order_date\n data_type: timestamp\n constraints:\n - type: not_null\n description: \"Date the order was placed\"\n - name: customer_id\n data_type: string\n constraints:\n - type: not_null\n description: \"Unique customer identifier\"\n tests:\n - dbt_utils.recency:\n field: order_date\n datepart: day\n interval: 1<\/code><\/pre>\n\n\n\n3. Create the dbt Model<\/strong>:<\/p>\n\n\n\nIn models\/orders.sql, define the model:<\/p>\n\n\n\n
SELECT\n order_id,\n order_date,\n customer_id\nFROM {{ ref('raw_orders') }}<\/code><\/pre>\n\n\n\n4. Set Up Great Expectations<\/strong>:<\/p>\n\n\n\nInstall: pip install great_expectations.<\/p>\n\n\n\n
Initialize: great_expectations init.<\/p>\n\n\n\n
Create an expectation suite for the orders table:<\/p>\n\n\n\n
import great_expectations as ge\n\ndf = ge.from_pandas(pd.read_csv('sample_orders.csv'))\ndf.expect_column_values_to_not_be_null('order_id')\ndf.expect_column_values_to_match_regex('order_id', '^ORD[0-9]{10}$')\ndf.save_expectation_suite('orders_expectations.json')<\/code><\/pre>\n\n\n\n5. Integrate with CI\/CD<\/strong>:<\/p>\n\n\n\nAdd a GitHub Action to validate the contract on push:<\/p>\n\n\n\n
name: Validate Data Contract\non: [push]\njobs:\n validate:\n runs-on: ubuntu-latest\n steps:\n - uses: actions\/checkout@v3\n - run: dbt run --profiles-dir .\n - run: great_expectations checkpoint run orders_checkpoint<\/code><\/pre>\n\n\n\n6. Test the Setup<\/strong>:<\/p>\n\n\n\nRun great_expectations checkpoint run orders_checkpoint to validate data.<\/p>\n\n\n\n
Run dbt run to materialize the model.<\/p>\n\n\n\n
This setup enforces schema constraints and quality checks, ensuring reliable data for consumers.<\/p>\n\n\n\n
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