# `mix pgflow.gen.flow_migration`
[🔗](https://github.com/agoodway/pgflow/blob/v0.1.0/lib/mix/tasks/pgflow.gen.flow_migration.ex#L1)

Generates an Ecto migration that registers a PgFlow flow in the database.

## Usage

    mix pgflow.gen.flow_migration MyApp.Flows.ArticleFlow
    mix pgflow.gen.flow_migration MyApp.Flows.ArticleFlow --migrations-path priv/repo/migrations

## Options

  * `--migrations-path` - Path to the migrations directory.
    Defaults to `priv/repo/migrations`.

## Generated SQL

The migration executes SQL statements that:
1. Create the flow record and PGMQ queue
2. Add each step with its dependencies and configuration

Example generated migration:

    defmodule MyApp.Repo.Migrations.CompileArticleFlow do
      use Ecto.Migration

      def up do
        execute "SELECT pgflow.create_flow('article_flow', 3, 5, 120)"
        execute "SELECT pgflow.add_step('article_flow', 'fetch_article', ARRAY[]::text[], NULL, NULL, NULL, NULL, 'single')"
        execute "SELECT pgflow.add_step('article_flow', 'summarize', ARRAY['fetch_article']::text[], NULL, NULL, NULL, NULL, 'single')"
      end

      def down do
        execute "DELETE FROM pgflow.deps WHERE flow_slug = 'article_flow'"
        execute "DELETE FROM pgflow.steps WHERE flow_slug = 'article_flow'"
        execute "DELETE FROM pgflow.flows WHERE flow_slug = 'article_flow'"
        execute "SELECT pgmq.drop_queue('article_flow')"
      end
    end

## Requirements

The flow module must:
1. Use `PgFlow.Flow`
2. Define a valid flow with `@flow` and at least one step
3. Be compilable (no syntax errors)

## Example

    # Define a flow
    defmodule MyApp.Flows.ArticleFlow do
      use PgFlow.Flow

      @flow slug: :article_flow, max_attempts: 3

      step :fetch do
        fn input, _ctx -> %{data: input} end
      end

      step :process, depends_on: [:fetch] do
        fn deps, _ctx -> %{result: deps.fetch} end
      end
    end

    # Generate the migration
    $ mix pgflow.gen.flow_migration MyApp.Flows.ArticleFlow

    # Run the migration
    $ mix ecto.migrate

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*Consult [api-reference.md](api-reference.md) for complete listing*