MyBatis的增删改查操作
搭建好mybatis之后 进行对数据库的操作
添加语句
在映射文件中添加语句
insert into student(name,age,score) values(#{name},#{age},#{score})
映射文件要放在与接口一个目录下
namespace：必须是对应接口的全限定名
id ：dao中的方法名字
parameterType：传入的参数类型 可以省略
添加语句后 获取主键的值 赋值给主键
insert into student(name,age,score) values(#{name},#{age},#{score})
select @@identity
2.删除语句
update student set name=#{name} ,age=#{age},score=#{score}
where id = #{id}
3.查询语句
/**
* 静态参数
* @param student
*/
void insertStudent(StudentBean student);
List selectStudentAll();
//根据姓名模糊查询
List selectStudentByName(String name);
//多参数查询 使用map作为方法参数
List selectStuByMap1(Map map);
List selectStuByMap2(Map map);
List selectStuByParameters1(String name , int age);
List selectStuByParameters2(String name , StudentBean student);
List selectStuByParameters3(@Param("name") String name , @Param("age")int age);
List selectStuByParameters4(@Param("name") String name , @Param("student") StudentBean student);
select * from student
select * from student where name like '%' #{name} '%'
select * from student where name like '%' #{name} '%' and age>#{age}
select * from student where name like '%' #{name} '%' and age > #{student.age}
select * from student where name like '%' #{0} '%' and age > #{1}
select * from student where name like '%' #{0} '%' and age > #{1.age}
动态参数
/**
* 动态参数
*/
//mybatis 动态参数类似域jstl《c:》
//if拼接 sql语句要跟上 where 1 =1
List selectStudentByIf(StudentBean student);
select * from student where 1=1
and name like '%' #{name} '%'
and age > #{age}
//不生成 1= 1 提高效率 自动在sql语句拼接的时候加上where 关键字
List selectStudentByWhere(StudentBean student);
select * from student
and name like '%' #{name} '%'
and age > #{age}
//多选一无锡人流医院 http://www.bhnfkyy.com/
List selectStudentByChoose(StudentBean student);
select * from student
where name like '%' #{name} '%'
where age > #{age}
where 1 = 2
List selectStudentByForeachArray(int[] ids);
select * from student
where id in
#{id}
List selectStudentByForeachList(List ids);
select * from student
where id in
#{id}
List selectStudentByForeachStudent(List students);
select * from student
where id in
#{student.id}
List selectStudentBySqlFragement();
select student
* from
//统计一张表的总数据条数 分页的总条数
int selectStudentCount();
select count(*) from student
