Oracle 0 first day of basic learning

First of all, we visited Oracle's official website: www.oracle.com Understand some of the site's resources, download pages and download instructions, although they have been to the official website to download the JDK and other related resources, but also just as a access to the information of the ordinary site, today, Step on the road to the database! Although the previous study of the database system tutorial, but the opportunity for the experiment is not much, after a large half a year, a variety of query, delete and so on, have been remembered. Today, it's the equivalent of a 0 foundation to start a new learning database!

Here are some basic events, here is just a simple introduction, you can search for more comprehensive:

1. Introduction to Oracle
A.oracle Company was founded in 1977, founder Ellison
B. Related events: acquisition of Sun Company in April 2009
What is C.oracle?
1) is an object-relational database management system
2) Extensive use in the areas of management information systems, enterprise data processing, Internet and e-commerce
3) Superior performance in database security and data integrity control
4) has a good cross-operating system, cross-hardware platform data interoperability capabilities
D. Company official website: www.oracle.com

Oracle Corporation (Oracle Software Systems, Inc.), the world's largest enterprise software company, is headquartered in Redwood Beach, California, USA. 1989 officially entered the Chinese market. In 2013, Oracle surpassed IBM as the world's second largest software company after Microsoft.

Almost all industries in the world are using Oracle technology, and 98 of Fortune 100 companies use Oracle technology. Oracle is the first company to develop and deploy 100% Internet-based enterprise software across the entire product line (database, business applications, and application software development and decision support tools). Oracle is the world's leading provider of information management software and the world's second largest independent software company.

3. Oracle's architecture
Oracle's architecture refers to the composition, working processes and principles of the database, as well as the organization and management of the data in the database.
Oracle servers provide development, comprehensive, and integrated information management, which is comprised of Oracle databases and Oracle instances
1) Database: A collection of physical operating system files or disks.

2) Example: A collection of background processes and memory structures that manage the database.
Consists of a set of Oracle background processes/threads and a shared memory area.

4. Oracle Network Configuration
After the Oracle product installation is complete, both the server and the client need network configuration to enable network connectivity.
Server-side configuration listener, the client configures the network service name.

Server-side listener configuration information includes listening protocols, addresses, and other related information.
The configuration information is saved in a file named Listener.ora. Automatically configure a listener when installing the server Software
The client's network service name configuration information includes the server address, the listener port number, and the database SID, and establishes a connection to the server's listener.
Configuration information is saved in a file named Tnsnames.ora
The NET Configuration assistant and Net Manager tools in Oracle can be used to configure listeners and network service names

5. Default User of Oracle
Only legitimate user accounts can access the Oracle database, and Oracle has several default database users: SYS, System, Scott
The Scott user is a demo account of the Oracle database that was created when the database was installed and the default password is Tiger

To connect to a database, you must have a user account, and each user has a default tablespace and a temporary table space.
The syntax for creating a user is as follows:
Created user <username> identified by <password>
Default Tablespace users
Temporary tablespace temp;

6, Oracle's query tool
Oracle's query tools include: SqlPlus, PL/SQL Developer, Developer

Do you have any doubts? Why not 2?

In fact, the second content is the use of Oracle installation and basic commands. Cango has been stressing: if the installation fails, do not search for any solution, directly reinstall the system, or the use of the latter will appear more serious problems, at the same time, it is also a reminder for beginners. Since the installation is not, I do not have a detailed description of how to install. Here are some of the commands to learn today:

1, connect the database: Sqlplus system/a//a is the default password, if the installation has been modified, please use your modified password

or sqlplus System/[email protected]//@ followed by the database instance name you set yourself: This is just to make it easier to see your user name when you have multiple instances

2. Exit

3. Show user view current DB instance

4, when the database instance password, with the SYS Super administrator to modify

First: Convert to Sys:conn/as SYSDBA

Then unlock: Alter user SYSTEM account unlock; This is just an example of the system user, and you can look at the hierarchy of administrators in Oracle

Last modified password: Alter user system identified by B; b is the new password, usually 8-bit, the front of the installation time is not enough to set the length, it will be reminded

After the successful modification, exit, the previous password will not successfully connect to the database

Oracle 0 first day of basic learning