Mysql Note 1 _ Database Development History

Database development history

Initial Stage-File System

Initial Stage-First Generation Database: database with a mesh model and hierarchical model.

Intermediate stage-second-generation databases: relational databases and structured query statements.

Advanced Stage-Third-Generation Database: "relational-object" type database.

Database Management System (DBMS)

Structured Query Language (Strutured Query Language)

Data Definition Language (DDL)

DML (Data Management Language) Data operation Language. Mysql is automatically submitted (auto commit), and Oracle is not automatically submitted by default.

DCL (Data Control Language) Data Control Language

TC (Transaction Control) Transaction Control

MYSQL database

Information_schema: stores information about database objects in the system, such as user table information, column information, permission information, character set information, and partition information (data dictionary table ).

Mysql: stores the user permission information and help information of the system.

Test: A Test database automatically created by the system, which can be used by any user.