mysql怎么添加一列数据类型

alter table (table_name) add (column_name) (col_type) [default|auto_increment|…]

#table_name=province, column_name=area, col_type=int

ALTER TABLE province ADD area INT;

#同时添加个字段

ALTER TABLE province ADD (

            area INT,

            population int

            );

alter table (table_name) drop COLUMN (column_name)

ALTER TABLE province DROP COLUMN area

#删除多个字段

ALTER TABLE province DROP COLUMN area, DROP COLUMN population