Module: MiniRecord::AutoSchema::ClassMethods

Defined in:
lib/mini_record/auto_schema.rb

Instance Method Summary collapse

Instance Method Details

#add_foreign_keys ⇒ Object

Add foreign keys for indexes with :foreign=>true option, if the key doesn't exists



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# File 'lib/mini_record/auto_schema.rb', line 143

def add_foreign_keys
  indexes.each do |name, options|
    if options[:foreign]
      column = options[:column].to_s
      unless foreign_keys.detect { |fk| fk[:options][:column] == column }
        to_table = reflect_on_all_associations.detect { |a| a.foreign_key.to_s==column }.table_name
        connection.add_foreign_key(table_name, to_table, options)
        foreign_keys << { :options=> { :column=>column } }
      end
    end
  end
end

#add_index(column_name, options = {}) ⇒ Object Also known as: index 



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# File 'lib/mini_record/auto_schema.rb', line 102

def add_index(column_name, options={})
  index_name = connection.index_name(table_name, :column => column_name)
  indexes[index_name] = options.merge(:column => column_name) unless indexes.key?(index_name)
  index_name
end

#auto_upgrade! ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 156

def auto_upgrade!
  return unless connection?

  if self == ActiveRecord::Base
    descendants.each(&:auto_upgrade!)
    clear_tables!
  else
    # If table doesn't exist, create it
    unless connection.tables.include?(table_name)
      # TODO: create_table options
      class << connection; attr_accessor :table_definition; end unless connection.respond_to?(:table_definition=)
      connection.table_definition = table_definition
      connection.create_table(table_name)
      connection.table_definition = ActiveRecord::ConnectionAdapters::TableDefinition.new(connection)
    end

    # Add this to our schema tables
    schema_tables << table_name unless schema_tables.include?(table_name)

    # Generate fields from associations
    if reflect_on_all_associations.any?
      reflect_on_all_associations.each do |association|
        foreign_key = association.options[:foreign_key] || "#{association.name}_id"
        type_key    = "#{association.name.to_s}_type"
        case association.macro
        when :belongs_to
          field foreign_key, :as => :integer unless fields.key?(foreign_key.to_s)
          if association.options[:polymorphic]
            field type_key, :as => :string unless fields.key?(type_key.to_s)
            index [foreign_key, type_key]
          else
            index foreign_key
          end
        when :has_and_belongs_to_many
          table = if name = association.options[:join_table]
                    name.to_s
                  else
                    [table_name, association.name.to_s].sort.join("_")
                  end
          unless connection.tables.include?(table.to_s)
            foreign_key             = association.options[:foreign_key] || association.foreign_key
            association_foreign_key = association.options[:association_foreign_key] || association.association_foreign_key
            connection.create_table(table, :id => false) do |t|
              t.integer foreign_key
              t.integer association_foreign_key
            end
            index_name = connection.index_name(table, :column => [foreign_key, association_foreign_key])
            index_name = index_name[0...connection.index_name_length] if index_name.length > connection.index_name_length
            connection.add_index table, [foreign_key, association_foreign_key], :name => index_name, :unique => true
          end
          # Add join table to our schema tables
          schema_tables << table unless schema_tables.include?(table)
        end
      end
    end

    # Add to schema inheritance column if necessary
    if descendants.present?
      field inheritance_column, :as => :string unless fields.key?(inheritance_column.to_s)
      index inheritance_column
    end

    # Remove fields from db no longer in schema
    (fields_in_db.keys - fields.keys & fields_in_db.keys).each do |field|
      column = fields_in_db[field]
      connection.remove_column table_name, column.name
    end

    # Add fields to db new to schema
    (fields.keys - fields_in_db.keys).each do |field|
      column  = fields[field]
      options = {:limit => column.limit, :precision => column.precision, :scale => column.scale}
      options[:default] = column.default unless column.default.nil?
      options[:null]    = column.null    unless column.null.nil?
      connection.add_column table_name, column.name, column.type.to_sym, options
    end

    # Change attributes of existent columns
    (fields.keys & fields_in_db.keys).each do |field|
      if field != primary_key #ActiveRecord::Base.get_primary_key(table_name)
        changed  = false  # flag
        new_type = fields[field].type.to_sym
        new_attr = {}

        # First, check if the field type changed
        if fields[field].sql_type.to_s.downcase != fields_in_db[field].sql_type.to_s.downcase
          logger.debug "[MiniRecord] Detected schema change for #{table_name}.#{field}#type from " +
                       "#{fields[field].sql_type.to_s.downcase.inspect} in #{fields_in_db[field].sql_type.to_s.downcase.inspect}" if logger
          changed = true
        end

        # Special catch for precision/scale, since *both* must be specified together
        # Always include them in the attr struct, but they'll only get applied if changed = true
        new_attr[:precision] = fields[field][:precision]
        new_attr[:scale]     = fields[field][:scale]

        # If we have precision this is also the limit
        fields[field][:limit] ||= fields[field][:precision]

        # Next, iterate through our extended attributes, looking for any differences
        # This catches stuff like :null, :precision, etc
        fields[field].each_pair do |att,value|
          next if att == :type or att == :base or att == :name # special cases
          value = true if att == :null && value.nil?
          if value != fields_in_db[field].send(att)
            logger.debug "[MiniRecord] Detected schema change for #{table_name}.#{field}##{att} "+
                         "from #{fields_in_db[field].send(att).inspect} in #{value.inspect}" if logger
            new_attr[att] = value
            changed = true
          end
        end

        # Change the column if applicable
        connection.change_column table_name, field, new_type, new_attr if changed
      end
    end

    remove_foreign_keys if connection.respond_to?(:foreign_keys)

    # Remove old index
    (indexes_in_db.keys - indexes.keys).each do |name|
      connection.remove_index(table_name, :name => name)
    end

    # Add indexes
    indexes.each do |name, options|
      options = options.dup
      unless connection.indexes(table_name).detect { |i| i.name == name }
        connection.add_index(table_name, options.delete(:column), options)
      end
    end

    add_foreign_keys if connection.respond_to?(:foreign_keys)

    # Reload column information
    reset_column_information
  end
end

#clear_tables! ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 116

def clear_tables!
  (connection.tables - schema_tables).each do |name|
    connection.drop_table(name)
    schema_tables.delete(name)
  end
end

#connection? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mini_record/auto_schema.rb', line 109

def connection?
  !!connection
rescue Exception => e
  puts "\e[31m%s\e[0m" % e.message.strip
  false
end

#field(*args) ⇒ Object Also known as: key, property, col 



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# File 'lib/mini_record/auto_schema.rb', line 50

def field(*args)
  return unless connection?

  options    = args.extract_options!
  type       = options.delete(:as) || options.delete(:type) || :string
  index      = options.delete(:index)

  args.each do |column_name|

    # Allow custom types like:
    #   t.column :type, "ENUM('EMPLOYEE','CLIENT','SUPERUSER','DEVELOPER')"
    if type.is_a?(String)
      # will be converted in: t.column :type, "ENUM('EMPLOYEE','CLIENT')"
      table_definition.column(column_name, type, options.reverse_merge(:limit => 0))
    else
      # wil be converted in: t.string :name
      table_definition.send(type, column_name, options)
    end

    # Get the correct column_name i.e. in field :category, :as => :references
    column_name = table_definition.columns[-1].name

    # Parse indexes
    case index
    when Hash
      add_index(options.delete(:column) || column_name, index)
    when TrueClass
      add_index(column_name)
    when String, Symbol, Array
      add_index(index)
    end
  end
end

#fields ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 36

def fields
  table_definition.columns.inject({}) do |hash, column|
    hash[column.name] = column
    hash
  end
end

#fields_in_db ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 43

def fields_in_db
  connection.columns(table_name).inject({}) do |hash, column|
    hash[column.name] = column
    hash
  end
end

#foreign_keys ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 123

def foreign_keys
  # fk cache to minimize quantity of sql queries
  @foreign_keys ||= {}
  @foreign_keys[:table_name] ||= connection.foreign_keys(table_name)
end

#indexes ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 23

def indexes
  return superclass.indexes unless superclass == ActiveRecord::Base

  @_indexes ||= {}
end

#indexes_in_db ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 29

def indexes_in_db
  connection.indexes(table_name).inject({}) do |hash, index|
    hash[index.name] = index
    hash
  end
end

#remove_foreign_keys ⇒ Object

Remove foreign keys for indexes with :foreign=>false option



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# File 'lib/mini_record/auto_schema.rb', line 130

def remove_foreign_keys
  indexes.each do |name, options|
    if options[:foreign]==false
      foreign_key = foreign_keys.detect { |fk| fk.options[:column] == options[:column].to_s }
      if foreign_key
        connection.remove_foreign_key(table_name, :name => foreign_key.options[:name])
        foreign_keys.delete(foreign_key)
      end
    end
  end
end

#reset_table_definition! ⇒ Object Also known as: reset_schema! 



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# File 'lib/mini_record/auto_schema.rb', line 91

def reset_table_definition!
  @_table_definition = nil
end

#schema {|table_definition| ... } ⇒ Object

Yields:



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# File 'lib/mini_record/auto_schema.rb', line 96

def schema
  reset_table_definition!
  yield table_definition
  table_definition
end

#schema_tables ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 9

def schema_tables
  @@_schema_tables ||= []
end

#table_definition ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 13

def table_definition
  return superclass.table_definition unless superclass == ActiveRecord::Base

  @_table_definition ||= begin
                           tb = ActiveRecord::ConnectionAdapters::TableDefinition.new(connection)
                           tb.primary_key(primary_key)
                           tb
                         end
end

#timestamps ⇒ Object 



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# File 'lib/mini_record/auto_schema.rb', line 87

def timestamps
  field :created_at, :updated_at, :as => :datetime, :null => false
end