Introduction to Database
First, the basic idea of the database: data, database, database management systems, database systems
- Data: Data (Data) may be used to record the information identification code is information specific forms.
- Database: (1) a database (Database, DB) refers to long-term storage in the computer, an organized collection of data may be shared. Simply put, the warehouse is used to store data.
(2) data in the database according to certain mathematical model that describes and storage, it has a smaller redundancy, higher data independence and easy scalability, can be shared for various users.
- Database management system: (1) a database management system (Database Management System, referred to as DBMS) is software for manipulating and managing large databases, between applications and the operating system for establishing, using and maintaining a database, comprising data definition, data manipulation, database management and database run establishment and maintenance.
(2) its database for unified management and control, in order to ensure the security and integrity of the database.
(3) users, database administrators perform database maintenance by DBMS DBMS data by accessing the database.
(4) which enables multiple applications to users using different methods and at the same time or different times to create, modify and query a database.
(5) database management system is the core database system is a database management software.
(6) The database management system is to achieve the abstract sense the user data processing logic, computer software specifically converted into a physical data processing. With database management system, users can process data in an abstract sense, without regard to the layout and the physical location of the data on your computer.
(7) Most DBMS provides data definition language DDL and data manipulation language DML, structure and mode permissions for user-defined constraint database, implement the additional data, and delete files.
(8) common database management software: Oracle's Oracle, IBM's db2,
SQL server, Access, Sybase, MySQL (open source, free, cross-platform).
- Database Systems: (1) Database Systems (Data Base System, referred to as DBS) is a software, database administrators and data components.
(2) As long as the software including the operating system, various host languages, utilities, and database management systems.
(3) a database managed by the unified database management system, data insertion, modification, and retrieval to be performed by both database management systems.
(4) database administrator is responsible for creating, monitoring and maintenance of the entire database, the data can be used by any person is entitled to effective use.
Second, the relational database
1. Relational Databases
2. relational database storage structures
3. Common relational database products
Three, SQL language
SQL (Structured Query Language, Structured Query Language) is a standard relational database language, have access to data, query data, update data and so on. It is divided into different functions according to the data definition language, a data manipulation language data and control language.
- Data Definition Language
(1) Data Definition Language (Data Delinition Language, referred to as DDL) for creating databases and database objects, providing an object database operations.
(2) DDL major SQL statements include CREATE (create a database, data sheets, etc.), ALTER (change the definition of the table), DROP (delete the database, delete a table)
- Data Manipulation Language
(1) data manipulation language (Data Manipulation Language, referred to as DML) for manipulating data in the database.
(2) The main statements include: INSERT (insert data), UPDATE (modifying data), DELETE (delete data), SELECT database query language (one or more data according to user need to query from the database)
- Data Control Language
(1) Data Control Language (Data Control Language, short DCL) as long as the object that implements access control and operation of the database transaction. (That is, to control user access rights)
(2) The main statements include: GRANT (to recover the user's permission) (to increase user permissions), REVOKE,
COMMIT (commit the transaction), ROLLBACK (roll back the transaction).
4. Database Query Language (supplement)
(1) database query language (Data Query Language, referred DQL) is mainly used to query language, which is the SELECT statement.
One or more data (2) SELECT statement to query the database.
Two, MySQL installation and configuration
1. MySQL characteristics; (1) portability (2) strong data protection (3) providing a plurality of memory engine (4) powerful (5) to support large databases (6) run faster
2. MySQL installation (windows system)
(1) download MySQL
(2) Open the folder MySQL-Front_Setup
(3) Double-click the MySQL-Front Setup
(4) Click Next.
(5) Click Next.
(6) Click Install
(7) Click Install
(8) When finished, there will be the image below
（9）
Fill in localhost in the server where the character set in a click.
Click OK, it will pop up a password box, the password for root, after determining that the following
(10)
At this point, the download installed.
Method Two:
(1) Download
(2) Open the folder
（3）
Click Next.
(4) Click Next.
（5）
Click Next.
（6）
Click Next.
(7) Click Next.
(8) Click Install content will appear below the picture, with a green dot to the right,
(9) Click the Other Options menu, choose MySQL tool, select the MySQL command line, the picture will appear below the content
（10）
Enter the root, the picture will appear below the content
At this point, the installation is complete.
Method three: (1) Download
(1) Open the folder
(2) choose to register
(3) Open the folder key.txt, there is activation code
(4) the activation code copy and paste it into navicat for MySQL, click OK just fine.
The third recommendation software more useful
As used herein: I installed the software to send teachers