MySQL basics-create table _ MySQL

1. create a new table CREATETABLE table name (domain name data type column option []); mysqlcreatetablecustomer (c_idchar (5) primarykey, c_namevarchar (20), c_birthdate, c_sexchar (1) DEFAULT0 ); CREATE 1. CREATE a new table create table name (domain name data type column option [...]);

Mysql> create table customer (c_id char (5) primary key, c_name varchar (20), c_birth date, c_sex char (1)

DEFAULT '0 ');

Main options available in the create table command

Option	Description
AUTO_INCREMENT	Custom Auto-incrementing sequence
DEFAULT 'default'	Define the default value of a column
INDEX	Define indexes
[NOT] NULL	Allow/disable NULL values
PRIMARY KEY	Define column primary keys
UNIQUE	Define uniqueness
CHECK	Define the range/option of values that can be entered

Specify character set when creating a table

Mysql> create table customer (c_id char (5) primary key, c_name varchar (20), c_birth date, c_sex char (1) DEFAULT '0') CHARSET = utf-8;

2. show tables for all tables;

Mysql> show tables;

3. display the DESC table name of the table structure;

Mysql> DESC customer;

4. delete the drop table name;

Mysql> drop table customer;

5. data insertion and display

Insert data into table name (column name 1, column name 2... column name n) values (data 1, data 2... data n) into table );

Displays the data in the table. SELECT column name 1, column name 2... column name n

6. AUTO_INCREMENT auto-incrementing sequence

There are three necessary conditions for customizing the auto-increment sequence in mysql:

1. the data type must be INT, TINYINT, SMALLINT, etc.

2. use [PRIMARY_KEY] and so on to set its uniqueness (the auto-increment sequence number is generally UNIQUE and generally serves as the table's primary key or a UNIQUE column (UNIQUE ))

3. the attachment AUTO_INCREMENT keyword after Column definition

Mysql> create table goods (id INT auto_increment primary key, name varchar (30 ));
// Note: the value of AUTO_INCREMENT can be initialized. alter table name: AUTO_INCREMENT = 0;