Module: ChronoModel::Adapter::Migrations

Included in:
ChronoModel::Adapter
Defined in:
lib/chrono_model/adapter/migrations.rb

Instance Method Summary collapse

Instance Method Details

#add_column(table_name) ⇒ Object

If adding a column to a temporal table, creates it in the table in the temporal schema and updates the triggers.



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# File 'lib/chrono_model/adapter/migrations.rb', line 137

def add_column(table_name, *)
  return super unless is_chrono?(table_name)

  transaction do
    # Add the column to the temporal table
    on_temporal_schema { super }

    # Update the triggers
    chrono_public_view_ddl(table_name)
  end
end

#add_index(table_name, column_name, options = {}) ⇒ Object

If adding an index to a temporal table, add it to the one in the temporal schema and to the history one. If the ‘:unique` option is present, it is removed from the index created in the history table.



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# File 'lib/chrono_model/adapter/migrations.rb', line 109

def add_index(table_name, column_name, options = {})
  return super unless is_chrono?(table_name)

  transaction do
    on_temporal_schema { super }

    # Uniqueness constraints do not make sense in the history table
    options = options.dup.tap {|o| o.delete(:unique)} if options[:unique].present?

    on_history_schema { super table_name, column_name, options }
  end
end

#change_column(table_name) ⇒ Object

If removing a column from a temporal table, we are forced to drop the view, then change the column from the table in the temporal schema and eventually recreate the triggers.



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# File 'lib/chrono_model/adapter/migrations.rb', line 169

def change_column(table_name, *)
  return super unless is_chrono?(table_name)
  drop_and_recreate_public_view(table_name) { super }
end

#change_column_default(table_name) ⇒ Object

Change the default on the temporal schema table.



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# File 'lib/chrono_model/adapter/migrations.rb', line 176

def change_column_default(table_name, *)
  return super unless is_chrono?(table_name)
  on_temporal_schema { super }
end

#change_column_null(table_name) ⇒ Object

Change the null constraint on the temporal schema table.



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# File 'lib/chrono_model/adapter/migrations.rb', line 183

def change_column_null(table_name, *)
  return super unless is_chrono?(table_name)
  on_temporal_schema { super }
end

#change_table(table_name, options = {}, &block) ⇒ Object

If changing a temporal table, redirect the change to the table in the temporal schema and recreate views.

If the ‘:temporal` option is specified, enables or disables temporal features on the given table. Please note that you’ll lose your history when demoting a temporal table to a plain one.



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# File 'lib/chrono_model/adapter/migrations.rb', line 66

def change_table(table_name, options = {}, &block)
  transaction do

    # Add an empty proc to support calling change_table without a block.
    #
    block ||= proc { }

    case options[:temporal]
    when true
      if !is_chrono?(table_name)
        chrono_make_temporal_table(table_name, options)
      end

      drop_and_recreate_public_view(table_name, options) do
        super table_name, options, &block
      end

    when false
      if is_chrono?(table_name)
        chrono_undo_temporal_table(table_name)
      end

      super table_name, options, &block
    end

  end
end

#create_table(table_name, options = {}) ⇒ Object

Creates the given table, possibly creating the temporal schema objects if the ‘:temporal` option is given and set to true.



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# File 'lib/chrono_model/adapter/migrations.rb', line 8

def create_table(table_name, options = {})
  # No temporal features requested, skip
  return super unless options[:temporal]

  if options[:id] == false
    logger.warn "ChronoModel: Temporal Temporal tables require a primary key."
    logger.warn "ChronoModel: Adding a `__chrono_id' primary key to #{table_name} definition."

    options[:id] = '__chrono_id'
  end

  transaction do
    on_temporal_schema { super }
    on_history_schema { chrono_history_table_ddl(table_name) }

    chrono_public_view_ddl(table_name, options)
  end
end

#drop_table(table_name) ⇒ Object

If dropping a temporal table, drops it from the temporal schema adding the CASCADE option so to delete the history, view and triggers.



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# File 'lib/chrono_model/adapter/migrations.rb', line 97

def drop_table(table_name, *)
  return super unless is_chrono?(table_name)

  on_temporal_schema { execute "DROP TABLE #{table_name} CASCADE" }

  chrono_drop_trigger_functions_for(table_name)
end

#remove_column(table_name) ⇒ Object

If removing a column from a temporal table, we are forced to drop the view, then drop the column from the table in the temporal schema and eventually recreate the triggers.



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# File 'lib/chrono_model/adapter/migrations.rb', line 192

def remove_column(table_name, *)
  return super unless is_chrono?(table_name)
  drop_and_recreate_public_view(table_name) { super }
end

#remove_index(table_name) ⇒ Object

If removing an index from a temporal table, remove it both from the temporal and the history schemas.



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# File 'lib/chrono_model/adapter/migrations.rb', line 125

def remove_index(table_name, *)
  return super unless is_chrono?(table_name)

  transaction do
    on_temporal_schema { super }
    on_history_schema { super }
  end
end

#rename_column(table_name) ⇒ Object

If renaming a column of a temporal table, rename it in the table in the temporal schema and update the triggers.



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# File 'lib/chrono_model/adapter/migrations.rb', line 152

def rename_column(table_name, *)
  return super unless is_chrono?(table_name)

  # Rename the column in the temporal table and in the view
  transaction do
    on_temporal_schema { super }
    super

    # Update the triggers
    chrono_public_view_ddl(table_name)
  end
end

#rename_table(name, new_name) ⇒ Object

If renaming a temporal table, rename the history and view as well.



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# File 'lib/chrono_model/adapter/migrations.rb', line 29

def rename_table(name, new_name)
  return super unless is_chrono?(name)

  clear_cache!

  transaction do
    # Rename tables
    #
    on_temporal_schema { rename_table_and_pk(name, new_name) }
    on_history_schema  { rename_table_and_pk(name, new_name) }

    # Rename indexes
    #
    chrono_rename_history_indexes(name, new_name)
    chrono_rename_temporal_indexes(name, new_name)

    # Drop view
    #
    execute "DROP VIEW #{name}"

    # Drop functions
    #
    chrono_drop_trigger_functions_for(name)

    # Create view and functions
    #
    chrono_public_view_ddl(new_name)
  end
end