Mybatis关联表查询_5

谁践踏了优雅 2023-10-17 07:47 48阅读 0赞

使用Mybatis实现关联查询，分为一对一和一对多两种情况，最后并对ResultMap进行一个简要说明。

#### 创建表和数据 ####

创建教师表,班级表,学生表，

假设一个老师只负责教一个班，那么老师和班级之间的关系是一对一的关系。

假设一个班级有多个学生，那么班级和学生之间的关系是一对多的关系。

CREATE TABLE teacher(
        t_id number(5) PRIMARY KEY, 
        t_name VARCHAR2(20)
    );
    CREATE TABLE class(
        c_id number(5) PRIMARY KEY ,
        c_name VARCHAR2(20), 
        teacher_id number(5) references teacher(t_id)
    );
      
    --创建序列
    create sequence teacher_seq;
    create sequence class_seq;
    
    INSERT INTO teacher VALUES(teacher_seq.nextval,'mike');
    INSERT INTO teacher VALUES(teacher_seq.nextval,'john');
    
    INSERT INTO class VALUES(class_seq.nextval,'Java10', 1);
    INSERT INTO class VALUES(class_seq.nextval,'Java11', 2);
    commit;
    
    select * from teacher;
    select *from class;
    
    select * from teacher t,class s where t.t_id = s.teacher_id and s.c_id=1
    
    
    --学生表
    CREATE TABLE student(
        s_id number(5) PRIMARY KEY ,
        s_name VARCHAR2(20), 
        class_id number(5)
    );
    create sequence student_seq;--序列
    --FK
    alter table student add constraint fk_cid foreign key(class_id) references class(c_id)
    
    INSERT INTO student VALUES(student_seq.nextval,'zhangsan', 1);
    INSERT INTO student VALUES(student_seq.nextval,'wangwu', 1);
    INSERT INTO student VALUES(student_seq.nextval,'liufei', 1);
    INSERT INTO student VALUES(student_seq.nextval,'cuihua', 2);
    INSERT INTO student VALUES(student_seq.nextval,'zhangfei', 2);
    INSERT INTO student VALUES(student_seq.nextval,'xionger', 2);
    
    
    
    select * from student;
      --查询某一个班级的老师，学生信息
     SELECT * FROM class c, teacher t,student s where c.c_id = s.class_id and t.t_id=c.teacher_id and c.c_id=1

#### 一、一对一关联    ####

#### (1)、定义实体类 ####

package com.hlx.entity;
    
    import java.util.List;
    
    /**
     * Classes 班级表
     * 
     * 一个班级有多个学生
     * 
     * @author Administrator
     * 
     */
    public class Classes {
    	private int id; // c_id
    	private String name; // c_name
    
    	/**
    	 * class表中有一个teacher_id字段，所以在Classes类中定义一个teacher属性，
    	 * 用于维护teacher和class之间的一对一关系，通过这个teacher属性就可以知道这个班级是由哪个老师负责的
    	 */
    	private Teacher teacher;//
    
    	//使用一个List<Student>集合属性表示班级拥有的学生
    	public int getId() {
    		return id;
    	}
    
    	public void setId(int id) {
    		this.id = id;
    	}
    
    	public String getName() {
    		return name;
    	}
    
    	public void setName(String name) {
    		this.name = name;
    	}
    
    	public Teacher getTeacher() {
    		return teacher;
    	}
    
    	public void setTeacher(Teacher teacher) {
    		this.teacher = teacher;
    	}
    
    	public Classes(int id, String name, Teacher teacher) {
    		super();
    		this.id = id;
    		this.name = name;
    		this.teacher = teacher;
    	}
    
    	public Classes(int id) {
    		super();
    		this.id = id;
    	}
    
    	public Classes() {
    		super();
    	}
    
    	
    	@Override
    	public String toString() {
    		return "Classes [id=" + id + ", name=" + name + ", teacher=" + teacher
    				+ "]";
    	}
    	
    }

package com.hlx.entity;
    /**
     * teachar 老师类
     * @author Administrator
     *
     */
    public class Teacher {
    	private int id; // t_id
    	private String name; // t_name
    
    	public int getId() {
    		return id;
    	}
    
    	public void setId(int id) {
    		this.id = id;
    	}
    
    	public String getName() {
    		return name;
    	}
    
    	public void setName(String name) {
    		this.name = name;
    	}
    
    	public Teacher(int id, String name) {
    		super();
    		this.id = id;
    		this.name = name;
    	}
    
    	public Teacher(int id) {
    		super();
    		this.id = id;
    	}
    
    	@Override
    	public String toString() {
    		return "Teacher [id=" + id + ", name=" + name + "]";
    	}
    
    	public Teacher() {
    		super();
    	}
    	
    
    }

#### (2)定义sql映射文件ClassesMapper.xml ####

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.hlx.mapping.ClassesMapper">
    
     <select id="getClass" parameterType="int" resultMap="classMap">
     	select * from class s, teacher t where t.t_id = s.teacher_id and s.c_id=#{id}
     </select>
     
     
     <resultMap type="com.hlx.entity.Classes" id="classMap">
     <id property="id" column="c_id"/> 
     <result property="name" column="c_name"/> 
     
     <association property="teacher" javaType="com.hlx.entity.Teacher">
      <id property="id" column="t_id"/>
      <result property="name" column="t_name"/>
     </association>
     </resultMap>
     
     
     
      <select id="getClass2" parameterType="int" resultMap="ClassMap2">
        select * from class where c_id=#{id}
      </select>
      
      
      <resultMap type="com.hlx.entity.Classes" id="ClassMap2">
        <id property="id" column="c_id"/>
        <result property="name" column="c_name"/>
        
        <association property="teacher" column="teacher_id" select="getTeacher"/>
      </resultMap>
       
       
       <select id="getTeacher" parameterType="int" resultType="Teacher">
          select t_id id,t_name name from teacher where t_id=#{id}
       </select>
       
    </mapper>

在mybatis-conf.xml文件中注册ClassesMapper.xml

<mappers>
         <mapper resource="com/hlx/mapping/ClassesMapper.xml"/>
       </mappers>

**(3)测试类**

package com.hlx.test;
    
    import java.io.InputStream;
    import java.util.List;
    
    import org.apache.ibatis.io.Resources;
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    import org.apache.log4j.Logger;
    import org.junit.Test;
    
    import com.hlx.entity.Classes;
    import com.hlx.util.MyBatisUtil;
    
    
    /**
     * 测试类
     *s
     * 
     * @author Administrator
     * 
     */
    public class ClassesTest {
    	// 日志对象
    	private Logger logger = Logger.getLogger(ClassesTest.class);
    
    	
    
    	
    	/**
    	 * Classes [id=2, name=Java11, teacher=Teacher [id=2, name=john]]
    	 */
    	@Test
    	public void getId() {
    
    		SqlSession session = null;
    		try {
    			// 获得会话
    			session = MyBatisUtil.getSqlSession(true);
    
    			
    			// 映射sql的标识字符串
    			String statement = "com.hlx.mapping.ClassesMapper.getClass";
    
    			// 执行插入操作
    			Classes userinfos = session.selectOne(statement, 2);
    
    			logger.debug("查询数据!");
    
    			System.out.println(userinfos);
    
    		} catch (Exception e) {
    			// TODO: handle exception
    			e.printStackTrace();
    		} finally {
    			session.close(); // 对应一次数据库会话，会话结束必须关闭
    
    		}
    
    	}
    	/**
    	 * Classes [id=1, name=Java10, teacher=Teacher [id=1, name=mike]]
    	 */
    	@Test
    	public void getId2() {
    		
    		SqlSession session = null;
    		try {
    			// 获得会话
    			session = MyBatisUtil.getSqlSession(true);
    			
    			
    			// 映射sql的标识字符串
    			String statement = "com.hlx.mapping.ClassesMapper.getClass2";
    			
    			// 执行插入操作
    			Classes userinfos = session.selectOne(statement, 1);
    			
    			logger.debug("查询数据!");
    			
    			System.out.println(userinfos);
    			
    		} catch (Exception e) {
    			// TODO: handle exception
    			e.printStackTrace();
    		} finally {
    			session.close(); // 对应一次数据库会话，会话结束必须关闭
    			
    		}
    		
    	}
    }

#### 二、一对多关联 ####

#### (1)、定义实体类 ####

package com.hlx.entity;
    
    import java.util.List;
    
    /**
     * Classes 班级表
     * 
     * 一个班级有多个学生
     * 
     * @author Administrator
     * 
     */
    public class Classes {
    	private int id; // c_id
    	private String name; // c_name
    
    	/**
    	 * class表中有一个teacher_id字段，所以在Classes类中定义一个teacher属性，
    	 * 用于维护teacher和class之间的一对一关系，通过这个teacher属性就可以知道这个班级是由哪个老师负责的
    	 */
    	private Teacher teacher;//
    
    	//使用一个List<Student>集合属性表示班级拥有的学生
    	private List<Student> students;
    	
    	public List<Student> getStudents() {
    		return students;
    	}
    
    	public void setStudents(List<Student> students) {
    		this.students = students;
    	}
    
    	public int getId() {
    		return id;
    	}
    
    	public void setId(int id) {
    		this.id = id;
    	}
    
    	public String getName() {
    		return name;
    	}
    
    	public void setName(String name) {
    		this.name = name;
    	}
    
    	public Teacher getTeacher() {
    		return teacher;
    	}
    
    	public void setTeacher(Teacher teacher) {
    		this.teacher = teacher;
    	}
    
    	public Classes(int id, String name, Teacher teacher) {
    		super();
    		this.id = id;
    		this.name = name;
    		this.teacher = teacher;
    	}
    
    	public Classes(int id) {
    		super();
    		this.id = id;
    	}
    
    	public Classes() {
    		super();
    	}
    
    	@Override
    	public String toString() {
    		return "Classes [id=" + id + ", name=" + name + ", teacher=" + teacher
    				+ ", students=" + students + "]";
    	}
    
    	//注意添加学生集合后，必须重新生成写入
    }

package com.hlx.entity;
    /**
     * 学生类
     * @author Administrator
     *
     */
    public class Student {
    	private int id; // s_id
    	private String name; // s_name
    
    	public int getId() {
    		return id;
    	}
    
    	public void setId(int id) {
    		this.id = id;
    	}
    
    	public String getName() {
    		return name;
    	}
    
    	public void setName(String name) {
    		this.name = name;
    	}
    
    	public Student(int id, String name) {
    		super();
    		this.id = id;
    		this.name = name;
    	}
    
    	public Student() {
    		super();
    	}
    	
    
    	public Student(int id) {
    		super();
    		this.id = id;
    	}
    
    	@Override
    	public String toString() {
    		return "Student [id=" + id + ", name=" + name + "]";
    	}
    	
    	
    
    }

#### (2)定义sql映射文件ClassesMapper.xml ####

<select id="getOneToMany" parameterType="int" resultMap="ClassMap3">
            select * from class c, teacher t,student s where c.teacher_id=t.t_id and c.c_id=s.class_id and  c.c_id=#{id}
       </select>
       
       <resultMap type="com.hlx.entity.Classes" id="ClassMap3">
        <id property="id" column="c_id"/>
        <result property="name" column="c_name"/>
        
        <association property="teacher" column="teacher_id" javaType="com.hlx.entity.Teacher">
         <id property="id"  column="t_id"/>
         <result property="name" column="t_name"/>
        </association>
        
        <collection property="students" ofType="com.hlx.entity.Student">
         <id property="id" column="s_id"/>
         <result property="name" column="s_name"/>
        </collection>
       </resultMap>
       
    
     
     <select id="getOneToMany2" parameterType="int" resultMap="ClassMap4">
       select * from class where c_id=#{id}
     </select>
      
      <resultMap type="com.hlx.entity.Classes" id="ClassMap4">
       <id property="id" column="c_id"/>
       <result property="name" column="c_name"/>
       
       <association property="teacher" column="teacher_id" select="getTeacher2"/> 
        
       <collection property="students" ofType="com.hlx.entity.Student" column="c_id" select="getStudent"/>
      </resultMap>
    
    
      <select id="getTeacher2" parameterType="int" resultType="Teacher">
       select t_id id,t_name name from  teacher where t_id=#{id}
      </select>
      
    
      <select id="getStudent" parameterType="int" resultType="Student">
       select s_id id,s_name name from  student where class_id=#{id}
      </select>

**(3)测试类**

/**
    	 * Classes [id=2, name=Java11, teacher=Teacher [id=2, name=john], students=[Student [id=4, name=cuihua], Student [id=5, name=zhangfei], Student [id=6, name=xionger]]]
    	 */
    	@Test
    	public void getOneToMany1() {
    		
    		SqlSession session = null;
    		try {
    			// 获得会话
    			session = MyBatisUtil.getSqlSession(true);
    			
    			
    			// 映射sql的标识字符串
    			String statement = "com.hlx.mapping.ClassesMapper.getOneToMany";
    			
    			// 执行插入操作
    			Classes userinfos = session.selectOne(statement, 2);
    			
    			logger.debug("查询数据!");
    			
    			System.out.println(userinfos);
    			
    		} catch (Exception e) {
    			// TODO: handle exception
    			e.printStackTrace();
    		} finally {
    			session.close(); // 对应一次数据库会话，会话结束必须关闭
    			
    		}
    		
    	}
    	/**
    	 * 
    	 * Classes [id=1, name=Java10, teacher=Teacher [id=1, name=mike], students=[Student [id=1, name=zhangsan], Student [id=2, name=wangwu], Student [id=3, name=liufei]]]
    	 * */
    	@Test
    	public void getOneToMany2() {
    		
    		SqlSession session = null;
    		try {
    			// 获得会话
    			session = MyBatisUtil.getSqlSession(true);
    			
    			
    			// 映射sql的标识字符串
    			String statement = "com.hlx.mapping.ClassesMapper.getOneToMany2";
    			
    			// 执行插入操作
    			Classes userinfos = session.selectOne(statement, 1);
    			
    			logger.debug("查询数据!");
    			
    			System.out.println(userinfos);
    			
    		} catch (Exception e) {
    			// TODO: handle exception
    			e.printStackTrace();
    		} finally {
    			session.close(); // 对应一次数据库会话，会话结束必须关闭
    			
    		}
    		
    	}

其他的步骤省略.............

**三、ResultMap标签**

SQL 映射XML 文件一些初级的元素

<table style="list-style:none; width:616px; font-size:14px; color:rgb(51,51,51); border:0px!important; padding:0px!important; margin:0px!important; bottom:auto!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; min-height:auto!important; background:none!important"> 
 <tbody style="border:0px!important; bottom:auto!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; background:none!important"> 
  <tr style="list-style:none; border:0px!important; padding:0px!important; margin:0px!important; bottom:auto!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; background:none!important"> 
   <td style="list-style:none; border:0px!important; padding:0px!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:rgb(175,175,175)!important; background:none!important"> 
    <div style="list-style:none; border-width:0px 3px 0px 0px!important; padding:0px 0.5em 0px 1em!important; margin:0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important">
      2 
    </div> 
    <div style="list-style:none; border-width:0px 3px 0px 0px!important; padding:0px 0.5em 0px 1em!important; margin:0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important">
      3 
    </div> 
    <div style="list-style:none; border-width:0px 3px 0px 0px!important; padding:0px 0.5em 0px 1em!important; margin:0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important">
      4 
    </div> 
    <div style="list-style:none; border-width:0px 3px 0px 0px!important; padding:0px 0.5em 0px 1em!important; margin:0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important">
      5 
    </div> 
    <div style="list-style:none; border-width:0px 3px 0px 0px!important; padding:0px 0.5em 0px 1em!important; margin:0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important">
      6 
    </div> 
    <div style="list-style:none; border-width:0px 3px 0px 0px!important; padding:0px 0.5em 0px 1em!important; margin:0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important">
      7 
    </div> 
    <div style="list-style:none; border-width:0px 3px 0px 0px!important; padding:0px 0.5em 0px 1em!important; margin:0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important">
      8 
    </div> </td> 
   <td style="list-style:none; width:584px; border:0px!important; padding:0px!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; background:none!important"> 
    <div style="list-style:none; border:0px!important; padding:0px!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; background:none!important"> 
     <div style="list-style:none; border:0px!important; padding:0px 1em!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">1. cache – 配置给定模式的缓存</code> 
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     <div style="list-style:none; border:0px!important; padding:0px 1em!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">2. cache-ref – 从别的模式中引用一个缓存</code> 
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     <div style="list-style:none; border:0px!important; padding:0px 1em!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">3. resultMap – 这是最复杂而却强大的一个元素了，它描述如何从结果集中加载对象</code> 
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     <div style="list-style:none; border:0px!important; padding:0px 1em!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">4. sql – 一个可以被其他语句复用的SQL 块</code> 
     </div> 
     <div style="list-style:none; border:0px!important; padding:0px 1em!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">5.</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-weight:bold!important; font-size:1em!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">insert</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">– 映射</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-weight:bold!important; font-size:1em!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">INSERT</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">语句</code> 
     </div> 
     <div style="list-style:none; border:0px!important; padding:0px 1em!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">6.</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-weight:bold!important; font-size:1em!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">update</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">– 映射</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-weight:bold!important; font-size:1em!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">UPDATE</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">语句</code> 
     </div> 
     <div style="list-style:none; border:0px!important; padding:0px 1em!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">7.</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-weight:bold!important; font-size:1em!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">delete</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">– 映射DELEETE 语句</code> 
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     <div style="list-style:none; border:0px!important; padding:0px 1em!important; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-size:1em!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">8.</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-weight:bold!important; font-size:1em!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">select</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">- 映射</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-weight:bold!important; font-size:1em!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">SELECT</code> 
      <code style="border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; margin:0px!important; outline:0px!important; overflow:visible!important; padding:0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; min-height:auto!important; color:black!important; background:none!important">语句</code> 
     </div> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

resultMap属性：type为java实体类；id为此resultMap的标识。  
resultMap可以设置的映射：

`1. constructor – 用来将结果反射给一个实例化好的类的构造器`

`a) idArg – ID 参数；将结果集标记为ID，以方便全局调用`

`b) arg –反射到构造器的通常结果`

`2. id – ID 结果，将结果集标记为ID，以方便全局调用`

`3. result – 反射到JavaBean 属性的普通结果`

`4. association – 复杂类型的结合；多个结果合成的类型`

`a) nested result mappings – 几resultMap 自身嵌套关联，也可以引用到一个其它上`

`5. collection –复杂类型集合a collection` `of` `complex types`

`6. nested result mappings – resultMap 的集合，也可以引用到一个其它上`

`7. discriminator – 使用一个结果值以决定使用哪个resultMap`

`a)` `case` `– 基本一些值的结果映射的` `case` `情形`