Method: Gadget.dependencies

Defined in:
lib/gadget.rb

.dependencies(conn, *args) ⇒ Object

Return a collection enumerating the dependencies between tables in a database. A table a is considered to be dependent on a table b if a has a foreign key constraint that refers to b.

Usage

dependencies = Gadget.dependencies(conn)

Parameters

  • conn - a PG::Connection to the database

Returns

  • a Hash:

    table name

    an Array of table names



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# File 'lib/gadget.rb', line 257

def self.dependencies(conn, *args)
  _ = args.extract_options!

  tables = self.tables(conn)
  foreign_keys = self.foreign_keys(conn)
  tables.reduce({}) do | h, (tablename, _) |
    h[tablename] = []
    refs = foreign_keys[tablename]
    unless refs.nil?
      refs[:refs].each { | ref | h[tablename] << ref[:ref_name] }
    end
    h
  end
end