1.数据类型：字符类型：char(标准通用拉丁字符),nchar(汉字等其他字符),varchar2(长度可变字
符),nvarchar2,long;
数字类型：number(通用),integer,float
日期和时间：date,timestamps(分秒，时区)
行：rowid(逻辑地址),urowid（逻辑地址，内存地址）;
二进制:raw(size)(原始二进制数据),long raw,blob(二进制大型对象;最大 4G 字节),clob(字
符大型对象),nclob,bfile;
2.oracle WEB 管理页面：localhost:5560/isqlplus; localhost:5500/em

3.net 设置远程测试：tnsping datebasename；远程连接:sqlplus
name/password@datebasename;

4.创建表空间：create tablespace test
datafile 'test.dbf' size 10m autoextend on next 2m
maxsize unlimited
logging
permanent
extent management local autoallocate
blocksize 8k
segment space management manuaL;//段空间

5．创建用户并连接： create user "TEST" identified by "TEST"
default tablespace TEST
temporary tablespace TEMP
quota unlimited on TEST
quota unlimited on TEMP
grant "connect" to test//分配基本权限。
conn test/test;

6．重设用户密码：scott/tiger 为默认用户，alter user scott identified by tiger;
解锁：alter user scott account unlock;

7.sql 脚本的执行：@路径/filename.sql;

8.创建表：create table t1(c1 type 约束,c2 type 约束（not null,unique,check,primary
key））

9.查询：select distinct c1 from t1 where 条件 group by c1 having by 子条件
order by c1;

10．连接字符串：select c1 (as 可省) 列 1 ||c2 from t1;

11.单行函数：select lower(c1) from t1；upper 全大写，initcap 第一个字母大写，length；

12．Select Sysdate from dual(系统默认的空表)显示系统时
间,months_between(date,date);

13.round(数据,5 位数),to_date(1997-10-11,’yyyy-mm-dd’)，to_char()函数使用要转
换。

14.nvl(c1,0)把字段为空的值换为 0，nvl2(c1,1,0)不空的为 1，空的值为 0；

15.操作符：比较：=，<>,>=,<=,>,<；逻辑：and,or,not 其他：in/not in,between..and..,is null/is not null,like，exists/not exists； Eg:select count(distinct c1) as 种类 from t1 where c1 like ‘%l%’(模糊查询如 m_n)(c1 between 10 and 100) group by c1 order by c1 desc，c2 desc（不写就默认 asc） 16．聚合函数：count(*)返回所有行的记录数,min(c1),max(c1),sum(c1),avg(c1); Eg:select c1,count(*) from t1 group by c1 having by count(*)>1;(having 不能用
变量申明);等价于 select c1,count(*) as cn from t1 group by c1 where cn>1;