关于Oracle表及字段的注释

1、给表加注释
COMMENT ON TABLE land.landsellmend IS '补办出让';

2、查看表的COMMENT
SELECT * FROM USER_TAB_COMMENTS WHERE TABLE_NAME='LANDSELLMEND';

3、给字段加注释
comment on column document.doc.bid is '批号';

4、查看字段的COMMENT：
SELECT * FROM USER_COL_COMMENTS WHERE TABLE_NAME='LANDSELLMEND';

5、查看字段的详细信息
select
A.column_name 字段名,A.data_type 数据类型,A.data_length 长度,A.data_precision 整数位,
A.Data_Scale 小数位,A.nullable 允许空值,A.Data_default 缺省值,B.comments 备注
from
user_tab_columns A,user_col_comments B
where
A.Table_Name = B.Table_Name
and A.Column_Name = B.Column_Name
and A.Table_Name = 'LANDSELLMEND'