mysql数据库编码格式设置 mysql数据库编码查询

1.查看数据库编码格式

mysql> show variableslike 'character_set_database';

2.查看数据表的编码格式

mysql> showcreate table ;

3.创建数据库时指定数据库的字符集

mysql>create database character set utf8;

4.创建数据表时指定数据表的编码格式

create table tb_books (
name varchar(45) not null,
price double not null,
bookCount int not null,
author varchar(45) not null ) default charset = utf8;

5.修改数据库的编码格式

mysql>alter database character set utf8;

6.修改数据表格编码格式

mysql>alter table character set utf8;

7.修改字段编码格式

mysql>alter table change character set utf8;
mysql>alter table user change username username varchar(20) character set utf8 not null;

8.添加外键

mysql>alter table tb_product add constraint fk_1 foreign key(factoryid) references tb_factory(factoryid);
mysql>alter table add constraint foreign key REFERENCES ;
mysql>alter table tb_people drop foreign key fk_1;
mysql>alter table drop foreign key

9.删除外键

mysql>alter table tb_people drop foreign key fk_1;
mysql>alter table drop foreign key