Mysql 5.5 Learn to read notes from scratch

Chapter I.

1. What is a database?

The database contains two levels of meaning: the "warehouse" in which the data is stored, and the methods and techniques of data management.

2. Table

Row North is called a record, a column is called a field

3. Primary key

Primary key, which uniquely identifies each record in the table, cannot have two identical values on the primary key column

4. Database system

There are 3 main components of a database system

Database: Where the user stores data

Database management system: software for managing databases

Database application: A software supplement to the management database used to improve the processing power of the database system.

A database may contain many files, and a database system typically contains many databases.

5.SQL language

Structured query languate, structured querying language

Database definition Language (DDL): Drop,create,alter

Database manipulation Language (DML): Insert,update,delete

Database Query Language (DQL): Select

Database Control Language (DCL): Grant,revoke,commit,rollback

6. Database Access Technology

ODBC (Open database interconnect) passes a common interface for accessing different databases

A standard way to connect a database to a Java application using a JDBC (Java database connection)

7. What is MySQL

MySQL is a small relational database management system, compared with other large data u management systems such as Oracle,db2,sql server.

MySQL is small and has limited functionality, but it is small, fast, low cost, and it provides functionality that has been used for a slightly more complex application

Enough, these features are what MySQL calls the world's most popular open source database

Version 8.Mysql

Mysql Community Server (Community Edition): Completely free, but the official does not provide technical support

Mysql Enterprise Server (Corporate Edition Server): Pay, official telephone technical support

Advantages of 9.Mysql

Fast speed

MySQL is free for most personal use

Easy to use, low complexity, easy to learn

Can be run on many different system platforms, such as Windows,linux,unix,mac OS, etc.

Rich interface that provides APIs for languages such as C,c++,java,php,python,ruby

........

10. How to learn MySQL

Interest

tamping (hang) solid foundation

Learn new knowledge

Multi-Practice

Mysql 5.5 Learn to read notes from scratch