1.查询分页数据：
a.使用注解
mapper:
<select id="selectBlogByPage2" resultMap="blogResultMap">
select * from blog limit #{offset},#{pagesize}
</select>
接口：注解的value值要和mapper的占位参数一致。
List<Blog> selectBlogByPage2(@Param(value="offset") int offset, @Param(value="pagesize") int pagesize);
b.使用Map
mapper中的参数占位符要和测试中的map中的key一一对应
mapper:
<select id="selectBlogByPage2" resultMap="blogResultMap">
select * from blog limit #{offset},#{pagesize}
</select>
接口：
List<Blog> selectBlogByPage3(Map<String,Object> map);
测试：
@Test
public void testSelectBlogBySort(){
SqlSession session=MyBatisUtil.getSqlSession();
BlogMapper blogMapper=session.getMapper(BlogMapper.class);
Map<String,Object> map=new HashMap<String,Object>();
map.put("offset", 2);
map.put("pagesize", 3);
List<Blog> blogList=blogMapper.selectBlogByPage3(map);
session.close();
System.out.println(blogList);
}
2.插入-获取刚刚插入的id(自增id)
方式一：在mapper中配置 insert节点的属性 useGeneratedKeys="true" keyProperty=" "
<insert id="insertBlog" parameterType="Blog" useGeneratedKeys="true" keyProperty="id">
insert into blog
(title,author_id,state,featured,style)
values(
#{title},#{authorId},#{state},#{featured},#{style}
)
</insert>
方式二：
在全局配置文件配置settings选项
<settings>
<setting name="useGeneratedKeys" value="true"/>
</settings>
并且在mapper的insert节点配置属性 keyProperty=" "
方式三：适用于没有自增属性的数据库
<insert id="insertmMysql" parameterType="Blog">
<selectKey resultType="java.lang.Integer" order="AFTER" keyProperty="id">
SELECT LAST_INSET_ID()
</selectKey>
insert into blog
(title,author_id,state,featured,style)
values(
#{title},#{authorId},#{state},#{featured},#{style}
)
</insert>
3.批量删除
mapper:
<delete id="deleteBlogList" parameterType="java.util.List">
delete from blog where id in
<foreach collection="list" item="item" open="(" close=")" separator=",">
#{item}
</foreach>
</delete>
接口：
int deleteBlogList(List<Integer> ids)
测试：
@Test
public void testDeleteBlogList(){
SqlSession session=MyBatisUtil.getSqlSession();
BlogMapper blogMapper=session.getMapper(BlogMapper.class);
List<Integer> ids=Arrays.asList(4,5,7);
int blogList=blogMapper.deleteBlogList(ids);
session.commit();
session.close();
System.out.println(blogList);
}
原文：https://www.cnblogs.com/jyy599/p/12548215.html