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alter table tbl_name add col_name type
例如,給表增加一列weight
mysql>alter table pet add weight int
刪除列
alter table tbl_name drop col_name
例如，刪除列weight：
mysql>alter table pet drop weight
改變列
alter table tbl_name modify col_name type
例如，改變weight的類型：
mysql> alter table pet modify weight samllint
另一種方法是：
alter table tbl_name change old_col_name col_name type
例如：
mysql> alter table pet change weight weight samllint
給列更名
mysql>alter table pet change weight wei
給表更名
alter table tbl_name rename new_tbl
例如，把pet表更名為animal
mysql>alter table pet rename animal
