Class JoinClause

tests/comparison/query.py:567–606

A representation of a JOIN clause. Ex: SELECT * FROM foo JOIN [ON ] The member variable boolean_expr will be an instance of a boolean func defined below.

class JoinClause(object):
  '''A representation of a JOIN clause.

     Ex: SELECT * FROM foo <join_type> JOIN <table_expr> [ON <boolean_expr>]

     The member variable boolean_expr will be an instance of a boolean func
     defined below.

  ''&#x27;

  JOINS_TYPES = [
      'INNER',
      'LEFT',
      'RIGHT',
      'LEFT SEMI',
      'LEFT ANTI',
      'RIGHT SEMI',
      'RIGHT ANTI',
      'FULL OUTER',
      'CROSS']

  def __init__(self, join_type, table_expr, boolean_expr=None):
    self.join_type = join_type
    self.table_expr = table_expr
    self.boolean_expr = boolean_expr
    # This is used for nested types. It means that we are joining with an earlier aliased
    # element in the from clause. For example, "From customer t1 INNER JOIN t1.orders t2"
    # or "FROM customer t1 INNER JOIN t1.orders.lineitems t2 ON t1.comment = t2.comment"
    # are both lateral joins. However, "FROM customer t1 INNER JOIN customer.orders t2 ON
    # (t1.comment = t2.comment)" is not a lateral join.
    # TODO: consider renaming to is_nested_join
    self.is_lateral_join = False

  def __deepcopy__(self, memo):
    other = JoinClause(
        self.join_type,
        deepcopy(self.table_expr, memo),
        deepcopy(self.boolean_expr, memo))
    other.is_lateral_join = self.is_lateral_join
    return other


class WhereClause(object):