Class: Chicago::Database::MigrationFileWriter Private

Inherits:
Object
  • Object
show all
Defined in:
lib/chicago/database/migration_file_writer.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Writes Sequel migrations for the star schema

Instance Method Summary collapse

Constructor Details

#initialize(db, migration_directory) ⇒ MigrationFileWriter

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Creates a new migration file writer, given a Sequel::Database connection and a directory. If the directory does not exist, an error will be raised.



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# File 'lib/chicago/database/migration_file_writer.rb', line 10

def initialize(db, migration_directory)
  @db = db
  @migration_directory = migration_directory
end

Instance Method Details

#migration_file ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns the path the migration file has been written to.



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# File 'lib/chicago/database/migration_file_writer.rb', line 28

def migration_file
  @file ||= File.join(@migration_directory, 
                      "#{Time.now.strftime("%Y%m%d%H%M%S")}_auto_migration.rb")
end

#write_migration_file(schema) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Writes the migration file necessary for all defined facts and dimensions.



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# File 'lib/chicago/database/migration_file_writer.rb', line 17

def write_migration_file(schema)
  @file = nil
  type_converter = TypeConverters::DbTypeConverter.for_db(@db)
  tables = SchemaGenerator.new(type_converter).traverse(schema)

  File.open(migration_file, "w") do |fh|
    fh.write Sequel::MigrationBuilder.new(@db).generate_migration(tables)
  end
end