MyBatis 快速入门

MyBatis介绍

MyBatis的前身就是iBatis,iBatis本是apache的一个开源项目，2010年这个项目由apahce sofeware foundation 迁移到了google code，并且改名为MyBatis。

MyBatis优缺点

优点：简单、灵活、高效

缺点：移植性差

开发环境搭建

1、下载需要的MyBatis jar包

2、部署MyBatis jar包

3、编写MyBatis配置文件

<?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>
        <typeAliases>
        <typeAlias alias="Emp" type="com.accp.entity.Emp"/>
        </typeAliases>
    <environments default="development">
        <environment id="development">
        <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
            <property name="driver" value="oracle.jdbc.driver.OracleDriver"/>
            <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"/>
            <property name="username" value="scott"/>
            <property name="password" value="tiger"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/accp/uitl/EmpDaoMapper.xml"/>
    </mappers>
</configuration>
mybatis-config.xml

 4、创建持久化类和数据库接口 

 1 package com.accp.entity;
 2 
 3 import java.util.Date;
 4 
 5 
 6 public class Emp implements java.io.Serializable {
 7 
 8     // Fields
 9     
10     private int empno;
11     private String ename;
12     private String job;
13     private int mgr;
14     private Date hiredate;
15     private Double sal;
16     private Double comm;
17     private int deptno;
18     // Constructors
19     /** default constructor */
20     public Emp() {
21     }
22     
23     public Emp(int empno, String ename, String job, int mgr, Date hiredate,
24             Double sal, Double comm, int deptno) {
25         super();
26         this.empno = empno;
27         this.ename = ename;
28         this.job = job;
29         this.mgr = mgr;
30         this.hiredate = hiredate;
31         this.sal = sal;
32         this.comm = comm;
33         this.deptno = deptno;
34     }
35 
36     public int getEmpno() {
37         return empno;
38     }
39     public void setEmpno(int empno) {
40         this.empno = empno;
41     }
42     public String getEname() {
43         return ename;
44     }
45     public void setEname(String ename) {
46         this.ename = ename;
47     }
48     public String getJob() {
49         return job;
50     }
51     public void setJob(String job) {
52         this.job = job;
53     }
54     public int getMgr() {
55         return mgr;
56     }
57     public void setMgr(int mgr) {
58         this.mgr = mgr;
59     }
60     public Date getHiredate() {
61         return hiredate;
62     }
63     public void setHiredate(Date hiredate) {
64         this.hiredate = hiredate;
65     }
66     public Double getSal() {
67         return sal;
68     }
69     public void setSal(Double sal) {
70         this.sal = sal;
71     }
72     public Double getComm() {
73         return comm;
74     }
75     public void setComm(Double comm) {
76         this.comm = comm;
77     }
78     public int getDeptno() {
79         return deptno;
80     }
81     public void setDeptno(int deptno) {
82         this.deptno = deptno;
83     }
84 
85 
86 
87 
88 }
Emp持久化类
1 package com.accp.dao;
2 
3 import com.accp.entity.Emp;
4 
5 public interface IEmpDao {
6     public void insertEmp(Emp emp);
7     public void updateEmp(Emp emp);
8 }
数据库接口

5、创建SQL映射文件

<?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.accp.dao.IEmpDao">
    <insert id="insertEmp" parameterType="Emp" >
        INSERT INTO emp(empno,ename,job,mgr,hiredate,sal,comm,deptno)VALUES(#{empno},#{ename},#{job},#{mgr},#{hiredate},#{sal},#{comm},#{deptno})
    </insert>
    <update id="updateEmp" parameterType="Emp">
        UPDATE emp SET ename=#{ename},job=#{job},mgr=#{mgr},sal=#{sal} WHERE empno=#{empno}
    </update>
</mapper>
EmpDaoMapper.xml

6、创建书库接口和实现类

 1 package com.accp.daoImpl;
 2 
 3 import java.io.IOException;
 4 import java.io.Reader;
 5 
 6 import org.apache.ibatis.io.Resources;
 7 import org.apache.ibatis.session.SqlSession;
 8 import org.apache.ibatis.session.SqlSessionFactory;
 9 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
10 
11 import com.accp.dao.IEmpDao;
12 import com.accp.entity.Emp;
13 /**
14  * @author 孙洪雨
15  */
16 public class IEmpDaoImpl implements IEmpDao {
17     SqlSession session=null;
18     SqlSessionFactory sf=null;
19     Reader reader=null;
20     @Override
21     public void insertEmp(Emp emp) {
22             try {
23                 String resource="mybatis-config.xml";
24                 reader=Resources.getResourceAsReader(resource);
25                 SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
26                 sf=builder.build(reader);
27                 session=sf.openSession();
28                 IEmpDao dao=session.getMapper(IEmpDao.class);
29                 dao.insertEmp(emp);
30                 session.commit();
31             } catch (IOException e) {
32                 // TODO Auto-generated catch block
33                 e.printStackTrace();
34             }finally{
35                 if(session!=null){
36                     session.close();
37                 }
38             }
39         
40     }
41     @Override
42     public void updateEmp(Emp emp) {
43         try {
44             String resource="mybatis-config.xml";
45             reader=Resources.getResourceAsReader(resource);
46             SqlSessionFactoryBuilder bulder=new SqlSessionFactoryBuilder();
47             sf=bulder.build(reader);
48             session=sf.openSession();
49             IEmpDao dao=session.getMapper(IEmpDao.class);
50             dao.updateEmp(emp);
51             session.commit();
52         } catch (IOException e) {
53             // TODO Auto-generated catch block
54             e.printStackTrace();
55         }finally{
56             if(session!=null){
57                 session.close();
58             }
59         }
60     }
61 
62 }
IEmpDaoImpl

7、编写测试类进行测试

使用MyBatis实现数据表的查询

<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.accp.dao.IEmpDao">

<select id="findEmpByEmpNo" parameterType="int" resultType="com.accp.entity.Emp" >
    SELECT empno,ename,job,mgr,hiredate,sal,comm from Emp where  empno= #{empno}
</select>
</mapper>
select元素

select元素有如下设置：

1.使用selectOne方法

 1 package com.accp.daoImpl;
 2 
 3 import java.io.IOException;
 4 import java.io.Reader;
 5 
 6 import org.apache.ibatis.io.Resources;
 7 import org.apache.ibatis.session.SqlSession;
 8 import org.apache.ibatis.session.SqlSessionFactory;
 9 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
10 
11 import com.accp.dao.IEmpDao;
12 import com.accp.entity.Emp;
13 
14 public class IEmpDaoImpl implements IEmpDao {
15     SqlSessionFactory sf=null;
16     SqlSession session=null;
17     Reader reader=null;
18     @Override
19     public Emp findEmpByEmpNo(int empno) {
20         String resource="mybatis-config.xml";
21         Emp emp=null;
22         try {
23             reader=Resources.getResourceAsReader(resource);
24             SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
25             sf=builder.build(reader);
26             session=sf.openSession();
27             emp=session.selectOne("com.accp.dao.IEmpDao.findEmpByEmpNo", empno);
28         } catch (IOException e) {
29             // TODO Auto-generated catch block
30             e.printStackTrace();
31         }
32         return emp;
33     }
34 
35 }
selectOne()

2.session.getMapper()方法实现

 1 package com.accp.daoImpl;
 2 
 3 import java.io.IOException;
 4 import java.io.Reader;
 5 
 6 import org.apache.ibatis.io.Resources;
 7 import org.apache.ibatis.session.SqlSession;
 8 import org.apache.ibatis.session.SqlSessionFactory;
 9 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
10 
11 import com.accp.dao.IEmpDao;
12 import com.accp.entity.Emp;
13 
14 public class IEmpDaoImpl implements IEmpDao {
15     SqlSessionFactory sf=null;
16     SqlSession session=null;
17     Reader reader=null;
18     @Override
19     public Emp findEmpByEmpNo(int empno) {
20         String resource="mybatis-config.xml";
21         Emp emp=null;
22         try {
23             reader=Resources.getResourceAsReader(resource);
24             SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
25             sf=builder.build(reader);
26             session=sf.openSession();
27             IEmpDao dao=session.getMapper(IEmpDao.class);
28             emp=dao.findEmpByEmpNo(empno);
29         } catch (IOException e) {
30             // TODO Auto-generated catch block
31             e.printStackTrace();
32         }
33         return emp;
34     }
35 
36 }
getMapper()

 使用MyBatis实现结果映射

<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.accp.dao.IEmpDao">

<resultMap type="com.accp.entity.Emp" id="ResultMap">
    <id property="empno" column="empno"/>
    <result property="ename" column="ename"/>
    <result property="job" column="job"/>
    <result property="mgr" column="mgr"/>
    <result property="hiredate" column="hiredate"/>
    <result property="sal" column="sal"/>
    <result property="comm" column="comm"/>
</resultMap>
<select id="empResultMap" resultMap="ResultMap">
    select * from EMP 
</select>
</mapper>
ResultMap

  使用MyBatis实现数据表增删改操作

MyBatis的官方网站是https://code.google.com/p/mybatis/

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原文地址：https://www.cnblogs.com/sunhongyu/p/3663145.html