God works. 上帝的安排。
Not so bad. 不错。
No way! 不可能！
Don’t flatter me. 过奖了。
Hope so. 希望如此。
Go down to business. 言归正传。
I’m not going. 我不去了。
Does it serve your purpose？ 对你有用吗？
I don’t care. 我不在乎。
None of my business. 不关我事。
It doesn’t work. 不管用。
Your are welcome. 你太客气了。
It is a long story. 一言难尽。
Between us. 你知，我知。
Sure thing! 當然！
Talk truly. 有话直说。
查询表信息
select * from tab;
查询表空间信息
select * from dba_data_files;
查询表在哪个表空间中
select tablespace_name from dba_tables where table_name = your_tablename’ and owner=’表的owner’;
创建个用户表空间同时指定使用该表空间
create table your_table(name,type) tablespace your_tablespacename(name,type);
表的创建时间
select object_name,created from user_objects where object_name=upper(‘&table_name’);
表的大小
select sum(bytes)/(1024*1024) as “size(M)” from user_segments
where segment_name=upper(‘&table_name’);
看各个表空间的自由空间
select tablespace_name,sum(bytes)/1024/1024 free_Mbytes
from dba_free_space
group by tablespace_name
order by free_Mbytes
查看各个表空间占用磁盘情况
SQL> col tablespace format a20
SQL> select
b.file_id 文件ID号,
b.tablespace_name 表空间名,
b.bytes 字节数,
(b.bytes-sum(nvl(a.bytes,0))) 已使用,
sum(nvl(a.bytes,0)) 剩余空间,
sum(nvl(a.bytes,0))/(b.bytes)*100 剩余百分比
from dba_free_space a,dba_data_files b
where a.file_id=b.file_id
group by b.tablespace_name,b.file_id,b.bytes
order by b.file_id
快速做一个和原表一样的备份表
create table new_table as (select * from old_table);
查看表与表之间的关系
从两个数据字典中查，all_constraints(user_constraints)和all_cons_columns(user_cons_columns)
查外键：
select * from all_constraints
where constraint_type = ‘R’;
查外键中的关联字段：
select * from all_cons_columns;
Today,I upgrade the website from 2.3.2 to 2.5.1.Everything is ok except the Chinese posts appear garbled characters for a while(maybe 10 minutes).Then they are OK.
Day 1:
初始化表的位置：
cd $ORACLE_HOME/rdbms cd demo summit2.sql
这个角本可以初始化练习用的表
set LANG = AMERICAN_AMERICA.US7ASCII
*********************************
我们目前使用的是oralce 9i 9201 版本
恢复练习表命令：
sqlplus openlab/open123 @summit2.sql
登陆oracle的命令：
sqlplus 用户名/密码
show user 显示当前登陆的身份.
set pause on
set pause off 分页显示.
oracle中默认日期和字符是左对齐，数字是右对齐
table or view does not exist ; 表或示图不存在
The first strong rays of sunshine after the dark winter months lure many people outside, and as they sun themselves, the light prompts their bodies to produce feel-good hormones and vitamin D to stimulate their nervous system.
But the sun’s rays are also dangerous as is evidenced by sunburn. The UV rays destroy or alter cell nuclei. The skin can compensate only for part of the damage before it turns red, even when it has its own level of protection.
This level of protection varies depending on skin type and the intensity of the sunlight. It’s about 20 minutes for skin that has little or no natural brown. Therefore, the skin needs extra protection. A good way to protect the skin from the UV rays that can cause a burn is to avoid intense sunlight, says Swen Malte John, professor of dermatology at the Osnabrck university.
The most intense sunlight occurs at midday in the height of summer. But the sun can be strong enough at other times of day to seriously damage the skin.
It is nearly impossible to completely protect the body from sunlight, especially during a summer vacation.
“Clothing should cover as much skin as possible,” says Heidrun Holstein, a medical specialist at Germany’s consumer center in Karlsruhe. She recommends wide-brimmed hats and long-sleeved shirts made of light material and UV-proof material that lets in only a fraction of sunlight.
Those parts of the skin which are not covered by clothing, such as the face and hands, should be protected with sunblock. The most important criteria when selecting a sunblock is skin type. People with darker complexions have a higher level of protection in their skin and can thus select a lower protection factor, says Holstein.
Generally, the sun protection factor (SPF) should be 15 or higher. When going to the beach or into a snowy setting, where the sunlight is reflected, a higher SPF is recommended. It also helps to check the UV index, which places a numerical value on the expected peak sunburn-causing UV rays. In some countries it’s possible to find the forecast UV index on the Internet, and sometimes the index is given as part of the weather report.
A sunblock’s description should also contain a few key words and should indicate that the product protects not only against UV-B rays, but also UV-A. It also should provide some information about whether the product is water resistant.
There also are major differences in the ingredients of sunblocks. Dermatologists recommend so-called physical protection. Such products contain crystals made of micro-sized minerals that reflect UV rays, says John. The more chemical substances contained in the product, the greater the risk of an allergic reaction.
After exposure to sunlight the skin needs calm and care.
“A cool bath or a cold shower is especially good,” says Grohn. “Then use a moisturizing lotion or gel with a high amount of aloe vera.”