(related_column, column)
Register a "virtual column".
      This method is to be called when registering any virtual column.
      A virtual column makes use internaly of multiple catalog columns.
      A related key is an example of a virtual column.

      This method internaly generates a new group id that caller must pass to
      registerRelatedKeyColumn when registering those internal (and real)
      columns. This is because the same virtual column can be used more than
      once in a query without interferences from other uses, and hence must be
      put in separate groups, without having to know that there are other uses
      for the same virtual column.

      virtual_column
        Name of the virtual column to register.
      column
        Name of the "last" real column behind the virtual column. Comparisons
        done on the virtual column will happen on that real column instead.
        For example, it's "title" for "source_title" related key.
Register a "virtual column".
      This method is to be called when registering any virtual column.
      A virtual column makes use internaly of multiple catalog columns.
      A related key is an example of a virtual column.
Register a virtual column . This method is to be called when registering any virtual column . A virtual column makes use internaly of multiple catalog columns . A related key is an example of a virtual column .
def registerRelatedKey(related_column, column):
    """
      Register a "virtual column".
      This method is to be called when registering any virtual column.
      A virtual column makes use internaly of multiple catalog columns.
      A related key is an example of a virtual column.

      This method internaly generates a new group id that caller must pass to
      registerRelatedKeyColumn when registering those internal (and real)
      columns. This is because the same virtual column can be used more than
      once in a query without interferences from other uses, and hence must be
      put in separate groups, without having to know that there are other uses
      for the same virtual column.

      virtual_column
        Name of the virtual column to register.
      column
        Name of the "last" real column behind the virtual column. Comparisons
        done on the virtual column will happen on that real column instead.
        For example, it's "title" for "source_title" related key.
    """
def registerRelatedKey ( related_column , column ) :