alter table tbl_name add col_name type

例如,给表增加一列weight

mysql>alter table pet add weight int

删除列

alter table tbl_name drop col_name

例如，删除列weight：

mysql>alter table pet drop weight

改变列

alter table tbl_name modify col_name type

例如，改变weight的类型：

mysql> alter table pet modify weight samllint

另一种方法是：

alter table tbl_name change old_col_name col_name type

例如：

mysql> alter table pet change weight weight samllint

给列更名

mysql>alter table pet change weight wei

给表更名

alter table tbl_name rename new_tbl

例如，把pet表更名为animal

mysql>alter table pet rename animal

-alter table tbl_name add col_name type for example, to form an increase in weight mysql>　alter table pet add weight int　Remove Columns alter table tbl_name drop col_name For example, the deletion of column weight: mysql>　alter table pet drop weight　change out alter table tbl_name modify col_name type for example, the type of weight change: mysql>　alter table pet modify weight samllint　Another method is: alter table tbl_name change old_col_name col_name type for example: mysql>　alter table pet change weight weight samllint　to the column name mysql>　alter table pet change weight wei　renamed to table alter table tbl_name rename new_tbl for example, changed its name to the pet table animal mysql>　alter table pet rename animal