SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function toStartOfHour (alias datetime_desc) (children 1)
     ExpressionList (children 1)
      Identifier b.datetime_value
    Function sum (alias value) (children 1)
     ExpressionList (children 1)
      Identifier b.value
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier vt (alias b)
   ExpressionList (children 1)
    Function toStartOfHour (children 1)
     ExpressionList (children 1)
      Identifier b.datetime_value
