查看表结构
select COLUMN_NAME,DATA_TYPE,DATA_LENGTH from user_tab_columns where table_name='表名';
查看表的注释
select * from user_tab_comments where Table_Name='表名';
查看表的字段注释
select * from user_col_comments where Table_Name='表名';
查看表的索引
select t.*,i.index_type from user_ind_columns t,user_indexes i
where t.index_name = i.index_name and t.table_name = i.table_name
and t.table_name = '表名';