SELECT RS.表名称,
                RS.表备注,
                RS.字段名称,
                RS.字段类型,
                CASE WHEN 字段类型 NOT IN ( 'NUMBER' , 'DATE')  THEN RS.数据长度/2 
                           ELSE RS.数据长度 END AS 字段长度,
               RS.整数位,
               RS.DATA_SCALE,
               RS.字段备注
FROM 
(
SELECT T.TABLE_NAME  AS 表名称,
        C1.COMMENTS AS 表备注,
        C2.COLUMN_NAME AS 字段名称,
        C2.DATA_TYPE AS 字段类型,
      --  C2.DATA_LENGTH AS 字段长度,
        C2.数据长度,
        C2.整数位,
        C2.DATA_SCALE,
        C3.COMMENTS AS 字段备注
 FROM 
 -- 查询指定用户下的表名称
 (SELECT TABLE_NAME FROM ALL_ALL_TABLES WHERE OWNER = 'GDBDCKXK') T 
 LEFT JOIN 
 -- 查询指定用户下的表注释
 (SELECT TABLE_NAME , 
         COMMENTS 
  FROM ALL_TAB_COMMENTS  -- 表注释
  WHERE OWNER = 'GDBDCKXK'
  ) C1 ON T.TABLE_NAME = C1.TABLE_NAME
 LEFT JOIN
 -- 查询指定用户下的表字段名称 
 (
 SELECT TABLE_NAME , 
        COLUMN_NAME,
        DATA_TYPE,
        DATA_LENGTH,
        DATA_LENGTH  AS 数据长度, 
         DATA_PRECISION AS 整数位  ,
         DATA_SCALE
  FROM ALL_TAB_COLUMNS WHERE OWNER = 'GDBDCKXK'
 )C2  ON T.TABLE_NAME = C2.TABLE_NAME 
 LEFT JOIN 
 -- 查询指定用户下的字段注释
 (
 SELECT TABLE_NAME ,
        COLUMN_NAME , 
        COMMENTS   -- 字段注释
 FROM ALL_COL_COMMENTS 
  WHERE OWNER = 'GDBDCKXK'
 ) C3
 ON T.TABLE_NAME = C3.TABLE_NAME 
 AND C2.COLUMN_NAME = C3.COLUMN_NAME
 ORDER BY T.TABLE_NAME
 ) RS 
 WHERE RS.表名称 = 'QL_TDSYQ'