ALTER TABLE 表名 MODIFY COLUMN 字段名 字段类型定义;
//修改字段类型
alter table aos_orgn modify column CGUID varchar(20),
modify column CPARENTID varchar(20),
modify column CCREATORID varchar(20);
//查询字段类型
show fields from `table_name` where field = 'filed_name'; show full columns from `table_name`;