Getting Started with dbt (data build tool)

What dbt does

dbt manages the T in ELT. You write SELECT statements; dbt compiles them into CREATE TABLE AS or CREATE VIEW AS statements and handles dependency ordering.

Project structure

models/
  staging/     # 1:1 with source tables, light renaming
  intermediate/ # joins and business logic
  marts/       # final wide tables for analytics

Ref function

{{ ref('stg_orders') }} creates a dependency between models. dbt builds a DAG and executes in correct order. This replaces brittle hardcoded schema.table references.

Tests

- name: order_id
  tests:
    - unique
    - not_null

Run dbt test after every build. Add custom SQL tests for business logic assertions.

Documentation

dbt docs generate && dbt docs serve produces a browsable data catalog with lineage graphs, column descriptions, and test results. Share the URL with analysts so they understand the data without asking engineers.