View Source Vtc.Ecto.Postgres.PgFramerate.Migrations (vtc v0.17.5)

Migrations for adding framerate types, functions and constraints to a Postgres database.

Link to this section Summary

Types

Details for an individual migration to support a Postgres type.

The type of object a migration is creating.

Alias for string that indicates the returned value is a raw SQL statement.

SQL value that can be passed as an atom or a string.

Full

Adds raw SQL queries to a migration for creating the database types, associated functions, casts, operators, and operator families.

Pg Types

Creates function schema as described by the Configuring Database Objects section above.

Adds framerate composite type.

Adds framerate_tgs enum type.

Pg Operators

Creates a custom :framerate, :framerate === operator that returns true if both the playback rate AND tags of a framerate are equal.

Creates a custom :framerate, :framerate === operator that returns true if both the playback rate AND tags of a framerate are equal.

Pg Functions

Creates framerate.is_ntsc(rat) function that returns true if the framerate is an NTSC drop or non-drop rate.

Creates framerate.__private__strict_eq(a, b) that backs the === operator.

Creates framerate.__private__strict_eq(a, b) that backs the === operator.

Functions

Returns the config-qualified name of the function for this type.

Link to this section Types

@type constraint_opt() ::
  {:check_value, sql_value()}
  | {:create_positive?, boolean()}
  | {:create_ntsc_tags?, boolean()}
  | {:create_ntsc_valid?, boolean()}
  | {:create_ntsc_drop_valid?, boolean()}

Opts for create_constraints/3.

@type migration_info() :: {migration_type(), raw_sql(), raw_sql()} | :skip

Details for an individual migration to support a Postgres type.

Either {migration_type, up_command, down_command} or :skip if the migration should be skipped.

@type migration_type() ::
  :schema | :type | :function | :operator | :operator_class | :cast | :other

The type of object a migration is creating.

@type raw_sql() :: String.t()

Alias for string that indicates the returned value is a raw SQL statement.

@type sql_value() :: String.t() | atom()

SQL value that can be passed as an atom or a string.

Link to this section Full

@spec run(include: Keyword.t(atom()), exclude: Keyword.t(atom())) :: :ok

Adds raw SQL queries to a migration for creating the database types, associated functions, casts, operators, and operator families.

This migration included all migrations under the Pg Types, Pg Operators, Pg Functions, and Pg Private Functions, headings.

Safe to run multiple times when new functionality is added in updates to this library. Existing values will be skipped.

Individual migration functions return raw sql commands in an {up_command, down_command} tuple.

options

Options

  • include: A list of migration functions to include. If not set, all sub-migrations will be included.

  • exclude: A list of migration functions to exclude. If not set, no sub-migrations will be excluded.

types-created

Types Created

Calling this macro creates the following type definitions:

CREATE TYPE framerate_tags AS ENUM (
  'drop',
  'non_drop'
);
CREATE TYPE framerate AS (
  playback rational,
  tags framerate_tags[]
);

schemas-created

Schemas Created

Up to two schemas are created as detailed by the Configuring Database Objects section below.

configuring-database-objects

Configuring Database Objects

To change where supporting functions are created, add the following to your Repo configuration:

config :vtc, Vtc.Test.Support.Repo,
  adapter: Ecto.Adapters.Postgres,
  ...
  vtc: [
    framerate: [
      functions_schema: :framerate,
      functions_prefix: "framerate"
    ]
  ]

Option definitions are as follows:

  • functions_schema: The postgres schema to store framerate-related custom functions.

  • functions_prefix: A prefix to add before all functions. Defaults to "framestamp" for any function created in the :public schema, and "" otherwise.

private-functions

Private Functions

Some custom function names are prefaced with __private__. These functions should not be called by end-users, as they are not subject to any API stability guarantees.

examples

Examples

defmodule MyMigration do
  use Ecto.Migration

  alias Vtc.Ecto.Postgres.PgFramerate
  require PgFramerate.Migrations

  def change do
    PgFramerate.Migrations.run()
  end
end

Link to this section Pg Constraints

Link to this function

create_constraints(table, field_name, opts \\ [])

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@spec create_constraints(sql_value(), sql_value(), [constraint_opt()]) :: :ok

Creates basic constraints for a PgFramerate / Framerate database field.

arguments

Arguments

  • table: The table to make the constraint on.

  • field: The name of the field being validated.

options

Options

  • check_value: The target value to check. If not set, table.field will be used.

  • create_positive?: boolean Add {field}_positive constraint (see below). Default: true.

  • create_ntsc_tags?: boolean Add {field}_ntsc_tags constraint (see below). Default: true.

  • create_ntsc_valid?: boolean Add {field})_ntsc_valid constraint (see below). Default: true.

  • create_ntsc_drop_valid?: boolean Add {field})_ntsc_drop_valid constraint (see below). Default: true.

constraints-created

Constraints created:

  • {field}_positive: Checks that the playback speed is positive.

  • {field}_ntsc_tags: Checks that both drop and non_drop are not set at the same time.

  • {field}_ntsc_valid: Checks that NTSC framerates are mathematically sound, i.e., that the rate is equal to (round(rate.playback) * 1000) / 1001.

  • {field}_ntsc_drop_valid: Checks that NTSC, drop-frame framerates are valid, i.e, are cleanly divisible by 30_000/1001.

examples

Examples

create table("my_table", primary_key: false) do
  add(:id, :uuid, primary_key: true, null: false)
  add(:a, Framerate.type())
  add(:b, Framerate.type())
end

PgRational.migration_add_field_constraints(:my_table, :a)
PgRational.migration_add_field_constraints(:my_table, :b)

Link to this section Pg Types

Link to this function

create_function_schemas()

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@spec create_function_schemas() :: migration_info()

Creates function schema as described by the Configuring Database Objects section above.

@spec create_type_framerate() :: migration_info()

Adds framerate composite type.

Link to this function

create_type_framerate_tags()

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@spec create_type_framerate_tags() :: migration_info()

Adds framerate_tgs enum type.

Link to this section Pg Operators

@spec create_op_strict_eq() :: migration_info()

Creates a custom :framerate, :framerate === operator that returns true if both the playback rate AND tags of a framerate are equal.

@spec create_op_strict_neq() :: migration_info()

Creates a custom :framerate, :framerate === operator that returns true if both the playback rate AND tags of a framerate are equal.

Link to this section Pg Functions

@spec create_func_is_ntsc() :: migration_info()

Creates framerate.is_ntsc(rat) function that returns true if the framerate is an NTSC drop or non-drop rate.

@spec create_func_strict_eq() :: migration_info()

Creates framerate.__private__strict_eq(a, b) that backs the === operator.

Link to this function

create_func_strict_neq()

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@spec create_func_strict_neq() :: migration_info()

Creates framerate.__private__strict_eq(a, b) that backs the === operator.

Link to this section Functions

@spec function(atom(), Ecto.Repo.t()) :: String.t()

Returns the config-qualified name of the function for this type.