ORACLE生成数据字典的语句

SELECT COL.TABLE_NAME,
       --COL.COLUMN_ID AS COLORDER,
       TT.COMMENTS,
       COL.COLUMN_NAME AS COLUMNNAME,
       CASE
         WHEN PKCOL.COLUMN_POSITION > 0 THEN
          '√'
         ELSE
          ''
       END AS ISPK,
       COL.DATA_TYPE AS TYPENAME,
       --DECODE(COL.DATA_TYPE, 'NUMBER', COL.DATA_PRECISION, COL.DATA_LENGTH) AS LENGTH,
       COL.DATA_LENGTH    占用字节数,
       COL.DATA_PRECISION AS PRECI,
       COL.DATA_SCALE     AS SCALE,
      
       CASE
         WHEN COL.NULLABLE = 'Y' THEN
          '√'
         ELSE
          ''
       END AS CISNULL,
      
       -- '' AS ISIDENTITY,
      
       COL.DATA_DEFAULT AS DEFAULTVAL,
       CCOM.COMMENTS    AS DETEXT /*,
COL.NUM_DISTINCT AS NUM_DISTINCT*/
  FROM USER_TAB_COLUMNS COL,
       USER_COL_COMMENTS CCOM,
       (SELECT AA.TABLE_NAME,
               AA.INDEX_NAME,
               AA.COLUMN_NAME,
               AA.COLUMN_POSITION
          FROM USER_IND_COLUMNS AA, USER_CONSTRAINTS BB
         WHERE BB.CONSTRAINT_TYPE = 'P'
           AND AA.TABLE_NAME = BB.TABLE_NAME
           AND AA.INDEX_NAME = BB.CONSTRAINT_NAME
        /*AND AA.TABLE_NAME IN ('AA')*/
        ) PKCOL,
       USER_TAB_COMMENTS TT
 WHERE COL.TABLE_NAME = CCOM.TABLE_NAME
   AND COL.COLUMN_NAME = CCOM.COLUMN_NAME
   AND COL.TABLE_NAME = TT.TABLE_NAME(+)
      -- AND COL.TABLE_NAME = 'AA'
   AND COL.COLUMN_NAME = PKCOL.COLUMN_NAME(+)
   AND COL.TABLE_NAME = PKCOL.TABLE_NAME(+)
 ORDER BY COL.TABLE_NAME,col.column_id