class Cql::Migrator

Reference < Object

The Migrator class is used to manage migrations and provides methods to apply, rollback, and redo migrations. The Migrator class also provides methods to list applied and pending migrations. Example Creating a new migrator

schema = Cql::Schema.define(:northwind, "sqlite3://db.sqlite3") do |s|
  table :schema_migrations do
    primary :id, Int32
    column :name, String
    column :version, Int64, index: true, unique: true
    timestamps
  end
end
migrator = Cql::Migrator.new(schema)

Example Applying migrations

migrator.up

Constants

Log

::Log.for(self)

Constructors

def new(schema : Schema)

Class Methods

def migrations

def migrations=(migrations : Array(Migration.class))

Instance Methods

def applied_migrations

Returns the applied migrations.

• @return [Array(MigrationRecord)] Example Listing applied migrations

migrator.applied_migrations

def down(steps : Int32 = Migrator.migrations.size)

Rolls back the last migration.

• @param steps [Int32] the number of migrations to roll back (default: 1) Example Rolling back migrations

migrator.down

def down_to(version : Int64)

Rolls back to a specific migration version.

• @param version [Int64] the version to roll back to Example Rolling back to a specific version

migrator.down_to(1_i64)

def last

Returns the last migration. Example Listing the last migration

migrator.last

@return [Migration.class | Nil]

def pending_migrations

Returns the pending migrations.

• @return [Array(MigrationRecord)] Example Listing pending migrations

migrator.pending_migrations

def print_applied_migrations

Prints the applied migrations. Example Listing applied migrations

migrator.print_applied_migrations

def print_pending_migrations

Prints the pending migrations. Example Listing pending migrations

migrator.print_pending_migrations

def print_rolled_back_migrations(m : Array(Migration.class))

Prints the rolled back migrations.

• @param m [Array(Migration.class)] the migrations to print

• @return [Nil] Example Listing rolled back migrations

migrator.print_rolled_back_migrations

def redo

Redoes the last migration. Example Redoing migrations

migrator.redo

def repo

def rollback(steps : Int32 = 1)

Rolls back the last migration.

• @param steps [Int32] the number of migrations to roll back (default: 1) Example Rolling back migrations

migrator.rollback

def schema

def up(steps : Int32 = Migrator.migrations.size)

Applies the pending migrations.

• @param steps [Int32] the number of migrations to apply (default: all) Example Applying migrations

migrator.up

def up_to(version : Int64)

Applies migrations up to a specific version.

• @param version [Int64] the version to apply up to Example Applying to a specific version

migrator.up_to(1_i64)