直接从 ALL_VIEWS 里查询视图定义脚本呢？

SELECT TEXT 
  FROM ALL_VIEWS 
 WHERE VIEW_NAME = 'ALL_CONS_COLUMNS'

不过视图脚本比较长，可能显示不完整

CREATE OR REPLACE  VIEW SYS.ALL_CONS_COLUMNS  AS 
    SELECT  /*+ PHC_MODE_ENFORCE(13) */
        O1.NAME OWNER, 
        O2.NAME CONSTRAINT_NAME, 
        O.NAME  TABLE_NAME,    
        COLS.NAME COLUMN_NAME,
        CASE WHEN CON.TYPE$ != 'C' THEN
                  CAST(SF_GET_INDEX_KEY_SEQ(I.KEYNUM, I.KEYINFO, COLS.COLID) AS NUMBER(10,0)) 
        ELSE 
                  CAST(NULL AS NUMBER(10,0)) 
        END POSITION 
    FROM TSYSOBJECTS O,
        TSYSOBJECTS O1,
        TSYSOBJECTS O2, 
        SYS.SYSCONS CON LEFT JOIN SYS.SYSINDEXES I ON I.ID=CON.INDEXID,
        SYS.SYSCOLUMNS COLS
    WHERE 
        O2.SUBTYPE$='CONS' AND O.SUBTYPE$ IN ('UTAB', 'STAB', 'VIEW') AND O2.PID=O.ID 
        AND O1.ID=O.SCHID  AND O1.TYPE$ = 'SCH' 
        AND CON.ID=O2.ID        
        AND COLS.ID=O.ID 
        AND (SF_COL_IS_IDX_KEY(I.KEYNUM, I.KEYINFO, COLS.COLID) = 1 OR 
             SF_COL_IS_CHECK_KEY(O2.INFO1, O2.INFO6, COLS.COLID) = 1)
  AND SF_CHECK_USER_TABLE_COL_PRIV_OPT(SYS_CONTEXT('USERENV', 'CURRENT_USERID'), SYS_CONTEXT('USERENV', 'CURRENT_USERTYPE'), O.ID, O1.PID, (SELECT INFO1 FROM TSYSOBJECTS WHERE TYPE$ = 'UR' AND ID = O1.PID), COLS.COLID, 0) = 1;

SELECT DBMS_METADATA.GET_DDL(OBJECT_TYPE => 'VIEW',NAME=>UPPER('ALL_CONS_COLUMNS'),SCHNAME => 'SYS');