用MyBatis实现数据的增加、删除、修改、查询和分页

Love The Way You Lie 2021-07-24 21:44 424阅读 0赞

**一 代码位置**

[https://gitee.com/cakin24/code/tree/master/08/MybatisCURD%20Page][https_gitee.com_cakin24_code_tree_master_08_MybatisCURD_20Page]

**二 关键代码**

1 UserMapper

package com.example.demo.mapper;
    
    import com.example.demo.entity.User;
    import com.github.pagehelper.Page;
    import org.apache.ibatis.annotations.*;
    import java.util.List;
    
    @Mapper
    public interface UserMapper {
    
        @Select("SELECT * FROM user WHERE id = #{id}")
        User queryById(@Param("id") int id);
    
        @Select("SELECT * FROM user")
        List<User> queryAll();
    
        @Insert({"INSERT INTO user(name,age) VALUES(#{name},#{age})"})
        int add(User user);
    
        @Delete("DELETE FROM user WHERE id = #{id}")
        int delById(int id);
    
        @Update("UPDATE user SET name=#{name},age=#{age} WHERE id = #{id}")
        int updateById(User user);
    
        @Select("SELECT * FROM user")
        Page<User> getUserList();
    }

2 PageHelperConfig

package com.example.demo.config;
    
    import com.github.pagehelper.PageHelper;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import java.util.Properties;
    
    @Configuration
    public class PageHelperConfig {
        @Bean
        public PageHelper pageHelper(){
            PageHelper pageHelper = new PageHelper();
            Properties p = new Properties();
            //1.offsetAsPageNum:设置为true时，会将RowBounds第一个参数offset当成pageNum页码使用.
            p.setProperty("offsetAsPageNum", "true");
            //2.rowBoundsWithCount:设置为true时，使用RowBounds分页会进行count查询.
            p.setProperty("rowBoundsWithCount", "true");
            //3.reasonable：启用合理化时，如果pageNum<1会查询第一页，如果pageNum>pages会查询最后一页。
            p.setProperty("reasonable", "true");
            pageHelper.setProperties(p);
            return pageHelper;
        }
    }

**三 运行程序**

**四 测试**

1 浏览器输入： [http://localhost:8080/user/add?name=cakin&age=1][http_localhost_8080_user_add_name_cakin_age_1]

浏览器输出

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70][]

数据库输出：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 1][]

2 浏览器输入： [http://localhost:8080/user/updatebyid?name=cakin24&age=24&id=1][http_localhost_8080_user_updatebyid_name_cakin24_age_24_id_1]

浏览器输出

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 2][]

数据库输出

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 3][]

3 浏览器输入： [http://localhost:8080/user/querybyid?id=1][http_localhost_8080_user_querybyid_id_1]

浏览器输出：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 4][]

4 浏览器输入： [http://localhost:8080/user/][http_localhost_8080_user]

浏览器输出：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 5][]

5 浏览器输入： [http://localhost:8080/user/delbyid?id=1][http_localhost_8080_user_delbyid_id_1]

浏览器输出：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 6][]

6 往数据库手动加几条数据

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 7][]

浏览器输入： [http://localhost:8080/listall?start=2][http_localhost_8080_listall_start_2]

浏览器输出：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 8][]

7 浏览器输入： [http://localhost:8080/listall2?pageNum=1&pageSize=2][http_localhost_8080_listall2_pageNum_1_pageSize_2]

浏览器器输出：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 9][]

[https_gitee.com_cakin24_code_tree_master_08_MybatisCURD_20Page]: https://gitee.com/cakin24/code/tree/master/08/MybatisCURD%20Page
[http_localhost_8080_user_add_name_cakin_age_1]: http://localhost:8080/user/add?name=cakin&age=1
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70]: /images/20210724/e523aa243fd54ec9a6138d11d3ca159a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 1]: /images/20210724/61f26f587da147f488647d36a5895a5b.png
[http_localhost_8080_user_updatebyid_name_cakin24_age_24_id_1]: http://localhost:8080/user/updatebyid?name=cakin24&age=24&id=1
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 2]: /images/20210724/f8f59c7845b6451d83a2aaaadc63ae04.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 3]: /images/20210724/1f5283434f9a4f85ad4b914f746c7bc5.png
[http_localhost_8080_user_querybyid_id_1]: http://localhost:8080/user/querybyid?id=1
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 4]: /images/20210724/71a4dda835224e589f09b5459ebddcbc.png
[http_localhost_8080_user]: http://localhost:8080/user/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 5]: /images/20210724/d2eeccafe894406fb60277f0787bda5f.png
[http_localhost_8080_user_delbyid_id_1]: http://localhost:8080/user/delbyid?id=1
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 6]: /images/20210724/f41f7328850b4b33b7831d8ed368cab9.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 7]: /images/20210724/f04fe065cf324983bb24447e08b98925.png
[http_localhost_8080_listall_start_2]: http://localhost:8080/listall?start=2
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 8]: /images/20210724/0c52c19c851445af95d2894ddd664e5e.png
[http_localhost_8080_listall2_pageNum_1_pageSize_2]: http://localhost:8080/listall2?pageNum=1&pageSize=2
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NoZW5ncWl1bWluZw_size_16_color_FFFFFF_t_70 9]: /images/20210724/8335224d88fd4aea93f24c0bc4fdc09f.png