SQL: Abfrage Tabellen mit Spaltenliste, Datentypen und Kommentaren

kleine Abfrage zu Tabellen und Spalten (inkl. Datentypen und Kommentare):

select TC.TABLE_NAME
     , TC.COLUMN_NAME
     , TC.DATA_TYPE
     , TC.DATA_LENGTH
     , COC.COMMENTS
     , TC.COLUMN_ID
  from USER_TAB_COLS TC
  join USER_COL_COMMENTS COC on TC.TABLE_NAME = COC.TABLE_NAME and TC.COLUMN_NAME = COC.COLUMN_NAME
 where TC.TABLE_NAME in ('D_1', 'D_2', 'D_3')
union all
select TABLE_NAME
     , null
     , null
     , null
     , COMMENTS
     , 0
  from USER_TAB_COMMENTS
 where TABLE_NAME in ('D_1', 'D_2', 'D_3')
 order by TABLE_NAME, COLUMN_ID
;