Create table 表名 （(列名,数据类型),(列名,数据类型),(列名,数据类型),(列名,数据类型),);

Alter  table tableName add column columName columnType comment ‘注释‘ ;

alter table author add column name varchar(20) comment ‘注释‘;

Alter table tableName change column columnName newColumnName columnType;

alter table author change column name  names varchar(20);

Alter table tableName modify column columnName columnType comment ‘注释‘;

alter table author modify column names varchar(10);

Alter table tableName drop column columnName;

alter table author modify column names varchar(10);

Alter table tableName rename to newTableName；

alter table author rename to authors;

Create table select * from oldtable;

create copy3 select * from authors;

Create table newTable select column1，column2，column3 from oldtable;

create table copy2 select id,author from authors;

Alter table newTableName like tableName;

create table copy like authors;

drop table table1,table2,table3;

drop table copy,copy2,copy3;