CLASS后跟随的ID值是这个自定义类型对象的ID，可以在SYSOBJECTS中查到类型对象名，你可以用下面这个SQL验证下

SELECT SCH.NAME AS SCHEMA_NAME
      ,TAB.NAME AS TABLE_NAME
      ,COL.COLID + 1 AS COLUMN_ID
      ,COL.NAME AS COLUMN_NAME
      ,COLCOMM.COMMENT$ AS COMMENTS
      ,CASE WHEN COL.TYPE$ NOT LIKE 'CLASS%' THEN SF_GET_TYPE_WITH_LENGTH(COL.TYPE$, COL.LENGTH$, COL.SCALE) 
            ELSE TYPESCH.NAME||'.'||TYPEOBJ.NAME
        END AS DATATYPE 
      ,CAST(CASE WHEN COL.TYPE$ NOT LIKE 'CLASS%' 
                   THEN CASE WHEN COL.TYPE$ IN ('NUMERIC','NUMBER','DEC','DECIMAL') THEN 22
                             WHEN COL.SCALE = 7 AND UNICODE() = 1 THEN COL.LENGTH$ * 4 
                             WHEN COL.SCALE = 7 AND UNICODE() = 0 THEN COL.LENGTH$ * 2
                             ELSE COL.LENGTH$ 
                         END 
             END
            AS NUMBER
           ) AS DATA_LENGTH
      ,CAST(CASE WHEN COL.TYPE$ NOT LIKE 'CLASS%' 
                   THEN CASE WHEN COL.TYPE$ IN ('NUMERIC','NUMBER','DEC','DECIMAL') THEN CASE WHEN COL.LENGTH$ = 0 THEN NULL ELSE COL.LENGTH$ END 
                             WHEN COL.TYPE$ IN ('INTERVAL YEAR TO MONTH','INTERVAL YEAR','INTERVAL MONTH','INTERVAL DAY','INTERVAL DAY TO HOUR','INTERVAL DAY TO MINUTE','INTERVAL DAY TO SECOND','INTERVAL HOUR','INTERVAL HOUR TO MINUTE','INTERVAL HOUR TO SECOND','INTERVAL MINUTE','INTERVAL MINUTE TO SECOND','INTERVAL SECOND') THEN ((COL.SCALE & 0XF0)>>4) 
                         END 
             END
            AS NUMBER
           ) AS DATA_PRECISION
      ,CAST(CASE WHEN COL.TYPE$ NOT LIKE 'CLASS%' 
                   THEN CASE WHEN COL.TYPE$ IN ('NUMERIC','NUMBER','DEC','DECIMAL') AND COL.LENGTH$=0 THEN NULL 
                             WHEN COL.TYPE$ IN ('INTERVAL YEAR TO MONTH','INTERVAL YEAR','INTERVAL MONTH','INTERVAL DAY','INTERVAL DAY TO HOUR','INTERVAL DAY TO MINUTE','INTERVAL DAY TO SECOND','INTERVAL HOUR','INTERVAL HOUR TO MINUTE','INTERVAL HOUR TO SECOND','INTERVAL MINUTE','INTERVAL MINUTE TO SECOND','INTERVAL SECOND') THEN (COL.SCALE & 0X0F) 
                             WHEN COL.TYPE$ LIKE 'TIMESTAMP%' THEN (COL.SCALE & 0XFF) 
                             ELSE COL.SCALE 
                         END 
             END
            AS NUMBER
           ) AS DATA_SCALE       
      ,COL.NULLABLE$ AS NULLALBE
      ,COL.DEFVAL AS DATADEFAULT
      ,CASE WHEN SF_COL_IS_IDX_KEY(IDXINFO.KEYNUM, IDXINFO.KEYINFO, COL.COLID) = 1 THEN 'Y' END AS PRIMARY_KEY
  FROM SYSOBJECTS TAB
  JOIN SYSOBJECTS SCH                 ON SCH.TYPE$ = 'SCH' AND SCH.ID = TAB.SCHID
  JOIN SYSCOLUMNS COL                 ON COL.ID = TAB.ID
  LEFT JOIN SYSCOLUMNCOMMENTS COLCOMM ON COLCOMM.SCHNAME = SCH.NAME AND COLCOMM.TVNAME = TAB.NAME AND COLCOMM.COLNAME = COL.NAME
  LEFT JOIN SYSCONS CONS              ON CONS.TYPE$ = 'P' AND CONS.TABLEID = TAB.ID
  LEFT JOIN SYSINDEXES IDXINFO        ON IDXINFO.ID = CONS.INDEXID
  LEFT JOIN SYSOBJECTS TYPEOBJ        ON TYPEOBJ.ID = SUBSTR(COL.TYPE$,6)
  LEFT JOIN SYSOBJECTS TYPESCH        ON TYPESCH.ID = TYPEOBJ.SCHID
 WHERE SCH.NAME = 'sbww'
   AND TAB.NAME = 'person'
   --AND COL.TYPE$ LIKE 'CLASS%'
 ORDER BY TAB.NAME,COL.COLID