MySQL Learning Note 1

1. The mainstream database

Oracle

IBM DB2

MySQL (acquired by Oracle)

Microsoft SQL Server

Sybase company Sybase

University of California, Berkeley, PostgreSQL

Open source && cross-platform: mysql,postgresql

Commercial && non-cross platform: SQL Server;

Cross-platform && not open Source: DB2 Oracle Sybase;

2. Enter the theme

MySQL Service name mysqld Port 3306;

Catalog:/var/lib/mysql

MySQL initial three databases; {Mysql,test,information_schema}

The data in the Information--schema library does not occupy disk space;

MySQL and test are saved on disk;

Common data types for 3.mysql:

Numeric type: int float;

Character type: char varchar (variable length);

Event Type: Year, Time, datetime (date + time)

Enum Type: Set (multiple selection) enum (radio);

Hey, eat at noon, next write

This article is from the "9379746" blog, please be sure to keep this source http://9389746.blog.51cto.com/9379746/1573969

MySQL Learning Note 1