ORACLE数据库导出表，字段名，长度，类型，字段注释，表注释语句

 --数据库导出表，字段名，长度，类型，字段注释，表注释语句
 SELECT T1.TABLE_NAME 英文表名,
       T1.COLUMN_NAME  字段名,
       T1.DATA_TYPE || '(' || T1.DATA_LENGTH || ')'  字段类型及长度,
       T2.COMMENTS  字段注释,
    t3.COMMENTS  表注释
  FROM USER_TAB_COLS T1, USER_COL_COMMENTS T2,user_tab_comments t3
 WHERE T1.TABLE_NAME = T2.TABLE_NAME
   AND T1.COLUMN_NAME = T2.COLUMN_NAME  and  t3.TABLE_NAME = t1.TABLE_NAME and    t1.TABLE_NAME LIKE 'GM_%'

--用这个好，可以查全部的

 SELECT
 c.table_name 英文表名 ,
 t.COMMENTS 中文表名称,
 cc.COLUMN_NAME 字段名,
 cc.COMMENTS 字段注释 ,
 c.DATA_TYPE || '(' || c.DATA_LENGTH || ')' 字段类型及长度
FROM
 dba_tab_columns c
 LEFT JOIN dba_col_comments cc ON c.table_name = cc.table_name
 AND c.column_name = cc.column_name
 LEFT JOIN dba_tab_comments t ON c.table_name = t.table_name
WHERE
 c.OWNER = 'S_GMJXK'
 AND c.TABLE_NAME LIKE 'GM_%'
ORDER BY
 c.table_name;