java学习--Mybatis使用方法

一、需要的包：mybatis,spring-jdbc,junit

二、需要添加的配置文件：主要是连接池的配置和映射文件的位置。

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE configuration PUBLIC "-//ibatis.apache.org//DTD Config 3.0//EN" 
    "http://ibatis.apache.org/dtd/ibatis-3-config.dtd">
<!-- 设置连接池 -->
<configuration>
    <environments default="environment">
        <environment id="environment">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="oracle.jdbc.driver.OracleDriver" />
                <property name="url"
                    value="jdbc:oracle:thin:@localhost:1521:xe" />
                <property name="username" value="system" />
                <property name="password" value="921407164a" />
            </dataSource>
        </environment>
    </environments>
    <!-- 指定映射文件的位置 -->
    <mappers>
        <mapper resource="entity/EmpMapper.xml" />
    </mappers>
</configuration>

三、写实体类

　注意：实体类的属性名与表的字段名要一样（大小写可以忽略）

 

四、添加映射文件，写sql语句

    映射文件格式：

<mapper namespace="dept">
    <!-- 
        id:要求唯一
        parameterType:参数类型，这写实体类的完整名字
     -->
    <insert id="insert" parameterType="entity.Dept">
        insert into t_dept 
                 values(t_dept_seq.nextval,#{deptName},#{addr})
    </insert>
    
    <select id="findAll" resultType="entity.Dept"> 
        select * from t_dept
    </select>
    
    <select id="findByid" parameterType="int" resultType="entity.Dept">
        select * from t_dept where id = #{id2}
    </select>
    
    <update id="update" parameterType="entity.Dept">
        update t_dept SET deptName = #{deptName},addr = #{addr} WHERE id = #{id} 
    </update>
    
    <delete id="delete" parameterType="int">
        delete from t_dept where id = #{id1}
    </delete>
    
</mapper>

 

<!-- 返回map类型的结果 -->
    <!-- 
         map是java.util.Map的简写形式。
     -->
    <select id="findById2" parameterType="int" resultType="map">
        Select * From t_emp Where id = #{id1}
    </select>
    
    <!-- 使用resultMap解决表的字段名与实体类的属性名不一致的情况 -->
    <resultMap type="entity.emp" id="empResultMap">
        <result property="empNo" column="id"/>
        <result property="ename" column="name"/>
    </resultMap>
    
    <select id="findByid3" parameterType="int" resultMap="empResultMap">
        select * from t_emp where id = #{id}
    </select>

 

五、 调用SqlSession对象提供的方法来访问数据库

测试方法内容

  1 package test;
  2 
  3 import java.util.List;
  4 import java.util.Map;
  5 
  6 import org.apache.ibatis.session.SqlSession;
  7 import org.apache.ibatis.session.SqlSessionFactory;
  8 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
  9 import org.junit.Before;
 10 import org.junit.Test;
 11 
 12 import entity.Dept;
 13 import entity.Employee;
 14 import entity.emp;
 15 import oracle.net.ns.SessionAtts;
 16 
 17 public class TestCase {
 18     SqlSession session;
 19     @Before
 20     public void init() {
 21         String config = "SqlMapConfig.xml";
 22         SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
 23         SqlSessionFactory ssf = ssfb.build(TestCase.class.getClassLoader()
 24                 .getResourceAsStream(config));
 25         session = ssf.openSession();
 26     }
 27     @Test
 28     public void test1() {
 29         String config = "SqlMapConfig.xml";
 30         //创建SqlSessionFactoryBuidler
 31         SqlSessionFactoryBuilder ssfb = 
 32                 new SqlSessionFactoryBuilder();
 33         
 34         //创建SqlSeeionFactory对象
 35         SqlSessionFactory ssf = 
 36                 ssfb.build(TestCase.class
 37                             .getClassLoader()
 38                                 .getResourceAsStream(config));
 39         //获得SqlSession对象
 40         SqlSession session =
 41                 ssf.openSession();
 42         //调用sqlsession对象提供的方法访问数据库
 43         Employee emp = new Employee();
 44         emp.setName("lisi");
 45         emp.setAge(33);
 46         session.insert("test.save", emp);
 47         //添加修改删除需要提交事务
 48         session.commit();
 49         //关闭SqlSession
 50         session.close();
 51     }
 52     
 53     @Test
 54     public void test2() {
 55         String config = "SqlMapConfig.xml";
 56         SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
 57         SqlSessionFactory ssf = ssfb.build(TestCase
 58                 .class.getClassLoader()
 59                     .getResourceAsStream(config));
 60         SqlSession session = ssf.openSession();
 61         Employee emp = new Employee();
 62         emp.setAge(21);
 63         emp.setName("王五");
 64         session.update("test.insert", emp);
 65         session.commit();
 66         session.close();
 67     }
 68     
 69     @Test
 70     public void test3() {
 71         List<Employee> list = session.selectList("test.findAll");
 72         System.out.println(list);
 73         //session归还连接
 74         session.close();
 75     }
 76     
 77     @Test
 78     public void test4() {
 79         Employee e  = session.selectOne("test.findByid", 1);
 80         System.out.println(e);
 81         session.close();
 82     }
 83     
 84     @Test
 85     public void test5() {
 86         Employee e  = session.selectOne("test.findByid", 1);
 87         e.setAge(e.getAge()*2);
 88         session.update("test.modify", e);
 89         session.commit();
 90         session.close();
 91     }
 92     
 93     @Test
 94     public void test6() {
 95         session.delete("test.delete",21);
 96         session.commit();
 97         session.close();
 98     }
 99     
100     @Test
101     public void test7() {
102         String config = "SqlMapConfig.xml";
103         SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
104         SqlSessionFactory ssf = ssfb.build(TestCase
105                 .class.getClassLoader()
106                     .getResourceAsStream(config));
107         SqlSession session = ssf.openSession();
108         Dept d1 = new Dept();
109         d1.setDeptName("研发");
110         d1.setAddr("北京");
111         Dept d2 = new Dept();
112         d2.setDeptName("销售");
113         d2.setAddr("北京");
114         session.insert("dept.insert", d1);
115         session.insert("dept.insert", d2);
116         session.commit();
117         session.close();
118     }
119     
120     @Test
121     public void test8() {
122         List<Dept> list = session.selectList("dept.findAll");
123         System.out.println(list);
124         session.close();
125     }
126     
127     @Test
128     public void test9() {
129         Dept d = session.selectOne("dept.findByid",1);
130         System.out.println(d);
131         session.close();
132     }
133     
134     @Test
135     public void test10() {
136         Dept d = session.selectOne("dept.findByid",1);
137         d.setAddr("上海");
138         session.update("dept.update", d);
139         session.commit();
140         session.close();
141     }
142     
143     @Test
144     public void test11() {
145         session.delete("dept.delete", 2);
146         session.commit();
147         session.close();
148     }
149     
150     @Test
151     //测试返回值是map类型的结果
152     public void test12 () {
153         Map date = 
154         session.selectOne("test.findById2",1);
155         //注意orcale数据库会将字段名统一变成大写格式
156         System.out.println(date.get("NAME"));
157         session.close();
158     }
159     
160     @Test
161     //测试 使用resultMap
162     public void test13() {
163         emp e = session.selectOne("test.findByid3",1);
164         System.out.println(e);
165     }
166 }
View Code

 

posted @ 2019-04-02 17:05  LLLLCCDD  阅读(428)  评论(0)  编辑  收藏  举报