SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier b
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier a
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier key
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier ID
     Literal \'1\'
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier ID
     Literal \'1\'
