mybatis-注解及其他

翻译 于 2017-12-18 09:18:56 发布 · 210 阅读 · 0

本文详细介绍MyBatis框架的高级应用技巧，包括如何通过注解实现增删改查操作，一对一、一对多及多对多关系的处理方法，并提供具体的代码示例。

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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<properties resource="datasource.properties"></properties>
<settings>
    <setting name="cacheEnabled" value="true"/>
</settings>
    <!-- 将我们的pojo注册到配置文件 -->
    <typeAliases>
        <package name="com.wode.pojo" />
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <package name="com/wode/mapper" />
    </mappers>
</configuration>

 

二：普通增删改查

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();
}

 

二：常用查询

2.1：一对一

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);
}




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);
    
}

 

2.2：一对多

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);
}




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);
}

2.3： 多对多

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);
}




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);
}




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);
}

在mapper包中的接口和xml文件链接，需：

SqlSession session = DbUtil.getSession();
    UserInfoMapper mapper = session.getMapper(UserInfoMapper.class);

通过mapper.findUserInfoById(id)等方式实现增删改查

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