1. View the database encoding format
show variables like 'character_set_database';
2. Check the encoding format of the data sheet
show create table <表名>;
3. Specify the character set of the database when creating the database
create database < database name > character set utf8;
4. Specify the encoding format of the data table when creating the data table
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. Modify the encoding format of the database
alter database < database name > character set utf8;
6. Modify the data table encoding format
alter table <表名> character set utf8;
7. Modify the field encoding format
alter table < table name > change < field name > < field name > < type > character set utf8; alter table user change username username varchar(20) character set utf8 not null;
8. Add foreign keys
alter table tb_product add constraint fk_1 foreign key (factoryid) references tb_factory(factoryid); alter table < table name > add constraint < foreign key name > foreign key < field name > REFERENCES < foreign table name >< field name > ;
9. Delete foreign keys
alter table tb_people drop foreign key fk_1; alter table <表 名> drop foreign key <外 键 名> ;