查询字段信息：
SELECT * FROM all_tab_columns WHERE OWNER = 'OWNER_NAME' AND TABLE_NAME='TABLE_NAME'-- 或者SELECT * FROM user_tab_columns WHERE TABLE_NAME='TABLE_NAME'
查询字段注释：
SELECT * FROM all_col_comments WHERE TABLE_NAME='TABLE_NAME'--或者SELECT * FROM user_col_comments WHERE TABLE_NAME='TABLE_NAME'
合起来查询：
注意：查询结果中，字段非空是 ‘N’，可为空是 ‘Y’
SELECT a.OWNER 模式,a.TABLE_NAME 表名, a.COLUMN_NAME 列名, a.DATA_TYPE 数据类型, a.DATA_LENGTH 长度, a.NULLABLE 非空, --(CASE WHEN a.NULLABLE = 'N' THEN 'Y' ELSE 'N' END) 非空,MENTS 注释FROM all_tab_columns aLEFT JOIN all_col_comments b ON a.OWNER = b.OWNER AND a.TABLE_NAME = b.TABLE_NAME AND a.COLUMN_NAME = b.COLUMN_NAMEWHERE a.OWNER = 'OWNER_NAME' AND a.TABLE_NAME = 'TABLE_NAME 'ORDER BY a.TABLE_NAME, a.COLUMN_ID--或者SELECT a.TABLE_NAME 表名, a.COLUMN_NAME 列名, a.DATA_TYPE 数据类型, a.DATA_LENGTH 长度, a.NULLABLE 非空, --(CASE WHEN a.NULLABLE = 'N' THEN 'Y' ELSE 'N' END) 非空,MENTS 注释FROM user_tab_columns aLEFT JOIN user_col_comments b ON a.TABLE_NAME = b.TABLE_NAME AND a.COLUMN_NAME = b.COLUMN_NAMEWHERE a.TABLE_NAME = 'TABLE_NAME 'ORDER BY a.COLUMN_ID
另，查询表注释：
SELECT * FROM user_tab_comments WHERE TABLE_NAME='CODE_GENERAL'
