dbt-sql-draw-archive-test

This dbt project holds macros and models for drawing bitmaps via SQL.

Shapes (circle, square, oval, etc)

These are intended to define a boundary of pixels, without an opinion on colour or size. They return a conditional express, which will be true when the coordinate falls within the boundary of the shape. The user chooses the colour Use like: update bitmap_pixels set colour = 'red' where {{ the_macro() }} or update bitmap_pixels set colour = case when {{ the_macro() }} then 'red' else 'green' end

Objects (rainbow, brick wall, dog, tree, etc)

These are intended to draw something specific, with defined colours. Ideally, they will also be scale-agnostic. They return a when..then statement which includes the colour.

Use like: update bitmap_pixels set colour = case {{ rainbow() }} else colour end

Filters (blur,anti-alias,invert)

These are intended to output colours based on the existing colour at each pixel, possibly also using neighbouring colours. Like objects, they return a when..then statement which includes the colour.

Local development

Prerequisites

• python 3
• dbt
• docker (for running postgres)

Creating a database

Spin up a local postgres container in docker:

docker run --name postgres-dbt-local -e POSTGRES_PASSWORD=my_password -p 5432:5432 -d postgres:13.2-alpine

Configure your ~/.dbt/profiles.yml to contain:

dbt_sql_draw:
  target: localpostgres
  outputs:
    localpostgres:
      type: postgres
      host: localhost
      user: postgres
      pass: my_password
      port: 5432
      dbname: postgres
      schema: sql_draw

Build the models

Install dbt, then:

dbt run --target localpostgres

Generate images

pip3 install -r requirements.txt
export POSTGRES_DB_NAME=postgres
export POSTGRES_USERNAME=postgres
export POSTGRES_PASSWORD=my_password
export POSTGRES_HOSTNAME=localhost
export POSTGRES_SCHEMA_NAME='sql_draw'

python3 ci/render_images_from_db.py

Now check the images/ directory

When finished

Remove local postgres container:

docker rm postgres-dbt-local