SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    Function if (alias _c) (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Literal UInt64_1
        Literal UInt64_1
      Identifier c
      Literal \'\'
    Function count (children 1)
     ExpressionList
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal \'\' (alias c)
   ExpressionList (children 1)
    Identifier _c
