数据库 数据的删除 SQL

-- delete  删除

-- delete from 表名  where 条件

-- 删除表中所有的数据
delete from student;

delete from student where  sid=7


delete from student where age is null

delete from student where age>28 or tid=102

-- insert  update  delete  dml语言:数据操纵语言  
-- 操纵的是数据 跟结构无关 不会影响到结构的