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论坛首页 › 学习交流 › 技术交流 › Java技术交流 › 正文

[学习交流] 【上海校区】Mybatis持久层注解开发

© aqiu 中级黑马   /  2019-6-1 01:05  /  738 人查看  /  0 人回复  /   1 人收藏 转载请遵从CC协议 禁止商业使用本文

本帖最后由 aqiu 于 2019-6-14 20:55 编辑

1. 配置增删改查
[Java] 纯文本查看 复制代码
package com.wode.mapper;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.ResultMap;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import com.wode.pojo.User;

public interface UserMapper {
    //使用注解的方式新增用户
    @Insert("insert into users values(null,#{user.userName},#{user.userPwd},#{user.userType})")
    @Options(keyProperty="user.userId",useGeneratedKeys=true)
    public int addUser(@Param("user")User user);
    //注解的方式修改用户资料---多参数传递第二种方式
    @Update("update users set user_name=#{name} where user_id=#{id}")
    public int updateUserNameById(@Param("name")String name,@Param("id")int id);
    //注解的方式删除用户
    @Delete("delete from users where user_id=#{id}")
    public int delById(@Param("id") int id);

    @Select("select * from users")
/**    @Results({
        @Result(id=true,property="userId",column="user_id",javaType=Integer.class),
        @Result(property="userName",column="user_name",javaType=String.class),
        @Result(property="userPwd",column="user_pwd",javaType=String.class),
        @Result(property="userType",column="user_type",javaType=Integer.class)
    })
    */
    @ResultMap("userMap")
    public List<User> findAllUser();
}

2. 常用查询
[Java] 纯文本查看 复制代码
一对一 : @One

package com.wode.mapper;

import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.One;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.ResultMap;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import com.wode.pojo.User;

public interface UserMapper {
    //使用注解的方式新增用户
    @Insert("insert into users values(null,#{user.userName},#{user.userPwd},#{user.userType})")
    @Options(keyProperty="user.userId",useGeneratedKeys=true)
    public int addUser(@Param("user")User user);
    //注解的方式修改用户资料---多参数传递第二种方式
    @Update("update users set user_name=#{name} where user_id=#{id}")
    public int updateUserNameById(@Param("name")String name,@Param("id")int id);
    //注解的方式删除用户
    @Delete("delete from users where user_id=#{id}")
    public int delById(@Param("id") int id);

    @Select("select * from users")
/**    @Results({
        @Result(id=true,property="userId",column="user_id",javaType=Integer.class),
        @Result(property="userName",column="user_name",javaType=String.class),
        @Result(property="userPwd",column="user_pwd",javaType=String.class),
        @Result(property="userType",column="user_type",javaType=Integer.class)
    })
    */
    @ResultMap("userMap")
    public List<User> findAllUser();

    @Select("select * from users where user_id=#{id}")
    @ResultMap("userMap")
    public User findUserById(@Param("id") int id);



    //1:1
    @Select("select * from users where user_id=#{id}")
    @ResultMap("userMap")
    public User findUserAndInfo(@Param("id")int id);
}

[Java] 纯文本查看 复制代码
package com.wode.mapper;

import java.util.List;

import org.apache.ibatis.annotations.One;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;

import com.wode.pojo.UserInfo;

public interface UserInfoMapper {
    @Select("select * from userInfo")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class)
    })
    public List<UserInfo> findUserInfo();

    //user中外键查询数据
    @Select("select * from userInfo where user_id=#{id}")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class)
    })
    public UserInfo findByUser(@Param("id")int id);

    //1:1
    @Select("select * from userinfo where info_id=#{info_id}")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class),
        @Result(column="user_id",property="user",one=@One(select="com.wode.mapper.UserMapper.findUserById"))
    })
    public UserInfo findInfoAndUser(@Param("info_id") int id);

}


[Java] 纯文本查看 复制代码
一对多： @Many

public interface UserMapper {
    //使用注解的方式新增用户
    @Insert("insert into users values(null,#{user.userName},#{user.userPwd},#{user.userType})")
    @Options(keyProperty="user.userId",useGeneratedKeys=true)
    public int addUser(@Param("user")User user);
    //注解的方式修改用户资料---多参数传递第二种方式
    @Update("update users set user_name=#{name} where user_id=#{id}")
    public int updateUserNameById(@Param("name")String name,@Param("id")int id);
    //注解的方式删除用户
    @Delete("delete from users where user_id=#{id}")
    public int delById(@Param("id") int id);

    @Select("select * from users")
/**    @Results({
        @Result(id=true,property="userId",column="user_id",javaType=Integer.class),
        @Result(property="userName",column="user_name",javaType=String.class),
        @Result(property="userPwd",column="user_pwd",javaType=String.class),
        @Result(property="userType",column="user_type",javaType=Integer.class)
    })
    */
    @ResultMap("userMap")
    public List<User> findAllUser();

    @Select("select * from users where user_id=#{id}")
    @ResultMap("userMap")
    public User findUserById(@Param("id") int id);

    //一对多查询
    @Select("select * from users where user_id=#{id}")
    @Results({
        @Result(id=true,property="userId",column="user_id",javaType=Integer.class),
        @Result(property="userName",column="user_name",javaType=String.class),
        @Result(property="userPwd",column="user_pwd",javaType=String.class),
        @Result(property="userType",column="user_type",javaType=Integer.class),
        @Result(property="info",column="user_id",many=@Many(select="com.wode.mapper.UserInfoMapper.findByUser"))
    })
    public User findUserAndInfo(@Param("id")int id);
}

[Java] 纯文本查看 复制代码
public interface UserInfoMapper {
    @Select("select * from userInfo")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class)
    })
    public List<UserInfo> findUserInfo();

    //user中外键查询数据
    @Select("select * from userInfo where user_id=#{id}")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class)
    })
    public UserInfo findByUser(@Param("id")int id);

    @Select("select * from userInfo where info_id=#{infoId}")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class),
        @Result(column="user_id",property="user",one=@One(select="com.wode.mapper.UserMapper.findUserById"))
    })
    public UserInfo findInfoAndUser(@Param("infoId")int infoId);
}

[Java] 纯文本查看 复制代码
多对多： @Many 和@One

public interface UserMapper {
    //使用注解的方式新增用户
    @Insert("insert into users values(null,#{user.userName},#{user.userPwd},#{user.userType})")
    @Options(keyProperty="user.userId",useGeneratedKeys=true)
    public int addUser(@Param("user")User user);
    //注解的方式修改用户资料---多参数传递第二种方式
    @Update("update users set user_name=#{name} where user_id=#{id}")
    public int updateUserNameById(@Param("name")String name,@Param("id")int id);
    //注解的方式删除用户
    @Delete("delete from users where user_id=#{id}")
    public int delById(@Param("id") int id);

    @Select("select * from users")
/**    @Results({
        @Result(id=true,property="userId",column="user_id",javaType=Integer.class),
        @Result(property="userName",column="user_name",javaType=String.class),
        @Result(property="userPwd",column="user_pwd",javaType=String.class),
        @Result(property="userType",column="user_type",javaType=Integer.class)
    })
    */
    @ResultMap("userMap")
    public List<User> findAllUser();

    @Select("select * from users where user_id=#{id}")
    @ResultMap("userMap")
    public User findUserById(@Param("id") int id);

    //多对多查询
    @Select("select * from users where user_id=#{id}")
    @Results({
        @Result(id=true,property="userId",column="user_id",javaType=Integer.class),
        @Result(property="userName",column="user_name",javaType=String.class),
        @Result(property="userPwd",column="user_pwd",javaType=String.class),
        @Result(property="userType",column="user_type",javaType=Integer.class),
        @Result(property="course",column="user_id",many=@Many(select="com.wode.mapper.CourseMapper.findCourseByUser"))
    })
    public User findUserAndCourse(@Param("id")int id);




    @Select("select * from users where user_id in (select user_id from user_course where course_id=#{courseId})")
    @Results({
        @Result(id=true,property="userId",column="user_id",javaType=Integer.class),
        @Result(property="userName",column="user_name",javaType=String.class),
        @Result(property="userPwd",column="user_pwd",javaType=String.class),
        @Result(property="userType",column="user_type",javaType=Integer.class)
    })
    public User findUserByCourse(@Param("id")int courseId);
}

[Java] 纯文本查看 复制代码
public interface UserInfoMapper {
    @Select("select * from userInfo")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class)
    })
    public List<UserInfo> findUserInfo();

    //user中外键查询数据
    @Select("select * from userInfo where user_id=#{id}")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class)
    })
    public UserInfo findByUser(@Param("id")int id);

    @Select("select * from userInfo where info_id=#{infoId}")
    @Results({
        @Result(id=true,column="info_id",property="infoId",javaType=Integer.class),
        @Result(column="nickName",javaType=String.class,property="nickName"),
        @Result(column="email",property="email",javaType=String.class),
        @Result(column="user_id",property="user",one=@One(select="com.wode.mapper.UserMapper.findUserById"))
    })
    public UserInfo findInfoAndUser(@Param("infoId")int infoId);
}

[Java] 纯文本查看 复制代码
public interface CourseMapper {
    @Select("select * from course where course_id=#{id}")
    @Results({
        @Result(id=true,column="course_id",property="courseId",javaType=Integer.class),
        @Result(column="code",property="code",javaType=String.class),
        @Result(column="name",property="name",javaType=String.class)
    })
    public Course findCourseById(@Param("id")int id);


    @Select("select * from course where course_id in (select course_id from user_course where user_id=#{id})")
    @Results({
        @Result(id=true,column="course_id",property="courseId",javaType=Integer.class),
        @Result(column="code",property="code",javaType=String.class),
        @Result(column="name",property="name",javaType=String.class)
    })
    public Course findCourseByUser(@Param("uId")int id);


    @Select("select * from course where course_id=#{courseId}")
    @Results({
        @Result(id=true,column="course_id",property="courseId",javaType=Integer.class),
        @Result(column="code",property="code",javaType=String.class),
        @Result(column="name",property="name",javaType=String.class),
        @Result(property="users",column="course_id",many=@Many(select="com.wode.mapper.UserMapper.findUserByCourse"))
    })
    public Course findCourseAndUser(@Param("courseId")int courseId);
}

---------------------
来源：CSDN
原文：https://blog.csdn.net/m0_37779570/article/details/81514757


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