FeistelCipher.Migration (feistel_cipher v0.2.0)
View SourceMigrations create functions FeistelCipher needs to function.
Usage
To use migrations in your application you'll need to generate an Ecto.Migration
that wraps
calls to FeistelCipher.Migration
:
mix ecto.gen.migration add_feistel_cipher
Open the generated migration in your editor and call the up
and down
functions on
FeistelCipher.Migration
:
defmodule MyApp.Repo.Migrations.AddFeistelCipher do
use Ecto.Migration
def up, do: FeistelCipher.Migration.up()
def down, do: FeistelCipher.Migration.down()
end
This will run all of FeistelCipher's versioned migrations for your database.
Now, run the migration to create the table:
mix ecto.migrate
Isolation with Prefixes
FeistelCipher supports namespacing through PostgreSQL schemas, also called "prefixes" in Ecto. With prefixes your jobs table can reside outside of your primary schema (usually public) and you can have multiple separate job tables.
To use a prefix you first have to specify it within your migration:
defmodule MyApp.Repo.Migrations.AddPrefixedFeistelIdJobsTable do
use Ecto.Migration
def up, do: FeistelCipher.Migration.up(prefix: "private")
def down, do: FeistelCipher.Migration.down(prefix: "private")
end
In some cases, for example if your "private" schema already exists and your database user in production doesn't have permissions to create a new schema, trying to create the schema from the migration will result in an error. In such situations, it may be useful to inhibit the creation of the "private" schema:
defmodule MyApp.Repo.Migrations.AddPrefixedFeistelIdJobsTable do
use Ecto.Migration
def up, do: FeistelCipher.Migration.up(prefix: "private", create_schema: false)
def down, do: FeistelCipher.Migration.down(prefix: "private")
end
Migrating Without Ecto
If your application uses something other than Ecto for migrations, be it an external system or another ORM, it may be helpful to create plain SQL migrations for FeistelCipher database schema changes.
The simplest mechanism for obtaining the SQL changes is to create the migration locally and run
mix ecto.migrate --log-migrations-sql
. That will log all of the generated SQL, which you can
then paste into your migration system of choice.
Alternatively, if you'd like a more automated approach, try using the feistel_id_migations_sql
project to generate up
and down
SQL migrations for you.
Summary
Functions
Run the down
changes.
Returns the SQL for dropping a trigger for a table to encrypt a source
field to a target
field.
Run the up
changes.
Returns the SQL for creating a trigger for a table to encrypt a source
field to a target
field.
Functions
Run the down
changes.
Example
Run migrations in an alternate prefix:
FeistelCipher.Migration.down(prefix: "payments")
Returns the SQL for dropping a trigger for a table to encrypt a source
field to a target
field.
Example
FeistelCipher.Migration.down_sql_for_table("posts", source: "seq", target: "id")
Run the up
changes.
Example
Run migrations in an alternate prefix:
FeistelCipher.Migration.up(prefix: "payments")
Returns the SQL for creating a trigger for a table to encrypt a source
field to a target
field.
Example
FeistelCipher.Migration.up_sql_for_table("posts", source: "seq", target: "id")