First Operation MySQL

where is the error----the MySQL command?

The answer semicolon should be in English environment and not in Chinese;

NOTICES:A: A single quotation mark to be used in a table and a backslash

1. Table creation: Createtabkle table name

(

Type of column name [constraint ],

Type of column name [constraint ],

Type of column name [constraint ],

);

Create a student id,name,age;

CREATE TABLE ' tb_student '

(

' id ' bigint DEFAULT NULL,

' Name ' VARCHAR (DEFAULT NULL),

' Age ' INT (one) DEFAULT NULL

) Engine=innodb DEFAULT Charset=utf8;

2, the constraint of the table:

A, non-null constraint DEFAULT not NULL

B, UNIQUE constraint:unique

Unique the contents of the column in the table must be unique

CREATE TABLE ' tb_student '

(

' id ' bigint DEFAULT NULL,

The ' name ' VARCHAR ( UNIQUE) is not NULL,

' Age ' INT (one) DEFAULT NULL

) Engine=innodb DEFAULT Charset=utf8;

Constraints on the C primary key :

1PRIMARY KEY is non-null and unique

2auto_increment. starting from 1. Step is 1,

The design of a primary key that uniquely identifies a row of data

1: Single Field primary key:

Composite PRIMARY Key

2 primary keys are divided into two types

1, Natural primary key

2, Proxy primary key

CREATE TABLE ' tb_student '

(

' id ' bigint DEFAULT NULL,

The ' name ' VARCHAR (UNIQUE) is not NULL,

' Age ' INT (one) DEFAULT NULL,

Primery KEY (' id ')

) Engine=innodb DEFAULT Charset=utf8;

Constraints on foreign keys

First Operation MySQL