MySQL Note 1_ database history

History of Database

The embryonic stage-file system

Primary stage-First generation database: Mesh model, hierarchical model database.

Intermediate stage-second generation database: relational database and structured query statement.

Advanced stage-third generation database: Relational-Object type database.

Database management System (DBMS)

　SQL (strutured query Language) Structured Query Language

DDL (data definition Language) Definition language

DML (Data Management Language) manipulation language. MySQL autocommit (auto commit), Oracle is not automatically committed by default.

DCL (Data Control Language)-controlled language

TC (Transaction control) thing controls

MySQL comes with a database

　　INFORMATION_SCHEMA: It mainly stores some database object information in the system, such as user table information, column information, permission information, character set information, partition information, etc. (Data dictionary table).

Mysql: Stores user rights and help information for the system.

Test: The system automatically creates a testing database that can be used by any user.