The basic operation of the database defined

First, relational and non-relational

1. Relational databases: storage format can directly reflect the relationship between the entities . Relational databases and common form is quite similar to relational database tables between the table and there is a lot of complex relationships. Common relational databases have Mysql, SqlServer and so on.
2. Non-relational databases: refers to the distributed, non-relational, not ensure compliance data storage systems ACID principles, such as MongoDB, Redis, Memcache . (ACID: atomicity, consistency, independence and persistence)

Second, the operation in the terminal database

1. Log database

mysql -uroot -p123456

2. (Sql statement requires a semicolon at the end) all database queries the database server

show databases;

3. Select one database operations

use 数据库名;

4. drop out

exit

Third, create a database table data

1. Create a database

create database test;

2. View data in the database table

show tables;

3. Creating a data table

CREATE TABLE pet (
	name VARCHAR(20),
	owner VARCHAR(20),
	species VARCHAR(20),
	sex CHAR(1),
	birth DATE,
	death DATE);

4. View data table structure

describe pet;

Fourth, the common data types

1. Value Type

2. Date / Time Types

3. string type

V. CRUD

1. By INSERT

INSERT INTO pet VALUES ('Puffball','Diane','hamster','f','1999-03-30',NULL);
INSERT INTO pet VALUES ('狗蛋','刘景','狗','公','1989-03-30',NULL);

2. 删 delete

delete from pet where name='Puffball';

3. 改 update

update pet set name='旺财' where owner='刘景';

4. Search select

select * from pet;