Mybatis框架的手动搭建以及Mybatis的常用基本应用

转载请注明出处 csdn wankaiming

1.在src下配置mybatisconfig.xml

<?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><!-- 设置属性文件 ,从中读取数据库访问所需的基本信息--><properties resource="database.properties"></properties><!-- 设置开发的环境 --><environments default="development">   <environment id="development">     <!-- 设置事务管理器 org.apache.ibatis.transaction.jdbc     JdbcTransactionFactory-->     <transactionManager type="jdbc"></transactionManager>               <!-- 设置数据源org.apache.ibatis.datasource.pooled     还有jndi要企业级应用服务器 还有unpooled -->     <dataSource type="pooled">           <!-- ognl -->        <property name="driver" value="${driver}"/>        <property name="url" value="${url}"/>        <property name="username" value="${username}"/>        <property name="password" value="${password}"/>        <property name="defaultAutoCommit" value="true"/>        <property name="poolMaximumActiveConnections" value="80"/>        <property name="poolMaximumIdleConnections" value="20"/>     </dataSource>   </environment></environments><!-- 设置映射文件 --><mappers><!-- resource不同于type,class写包名的 ，要写完整 -->   <mapper resource="testmybatis/po/Emp.xml" />   <mapper resource="testmybatis/po/Dept.xml" /></mappers></configuration>

2.database.properties属性文件配置  给出两个数据库的配置

#oracle

driver=oracle.jdbc.OracleDriver
url=jdbc:oracle:thin:@127.0.0.1:1521:orcl
username=exam
password=exam


#mysql
#driver=com.mysql.jdbc.Driver
#url=jdbc:mysql://127.0.0.1:3306/test
#username=root
#password=root

3.po文件的写法 演示常用功能

Dept.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 name="testmybatis.po.Dept">   <select id="getempbydept" parameterType="int" resultMap="deptempresult">   <!-- 不能换行 -->     Select  e.empno,e.ename,e.job,e.hiredate,e.sal,e.deptno,d.dname,d.loc From emp e Left Outer Join dept d On e.deptno=d.deptno Where d.deptno=#{deptno}   </select>      <resultMap type="testmybatis.po.Dept" id="deptempresult">       <id column="deptno" property="deptno"/>       <result column="dname" property="dname"/>        <result column="loc" property="loc"/>               <!-- 设置集合,ofType集合当中元素的类型 -->       <!-- 多个员工 用collection -->       <collection property="emp" ofType="testmybatis.po.Emp">       <id column="empno" property="empno" />       <result property="ename" column="ename" />       <result property="job" column="job" />       <result property="hiredate" column="hiredate" />       <result property="sal" column="sal" />       <result property="deptno" column="deptno" />              </collection>   </resultMap></mapper>

Emp.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"><!-- namespace必须写 DTD中虽然是可选的  namespace 可以用po名字来命名--><mapper namespace="testmybatis.po.Emp">   <!-- 配置下result可以返回数据,写上包名 -->   <!-- 结果集 主要使用在查询语句上 -->   <resultMap type="testmybatis.po.Emp" id="empresult">       <result property="empno" column="empno" />       <result property="ename" column="ename" />       <result property="job" column="job" />       <result property="hiredate" column="hiredate" />       <result property="sal" column="sal" />       <result property="deptno" column="deptno" />   </resultMap>         <!-- id名字可以自己取  查询操作 -->   <!-- 返回多行数据时，需要使用resultMap -->   <select id="getall" resultMap="empresult">     Select empno,ename,job,hiredate,sal,deptno From emp   </select>      <!-- 传递一个参数时，给出参数类型 ,返回一行数据时，使用resultType -->   <select id="getone" parameterType="int" resultType="testmybatis.po.Emp">      Select empno,ename,job,hiredate,sal,deptno From emp Where empno=#{empno}   </select>         <!-- 查询的时候多个参数的时候 如此配置 -->   <!-- 参数集 使用在查询语句的条件上 -->   <parameterMap type="testmybatis.po.Emp" id="empparameter">      <parameter property="job"/>      <parameter property="sal"/>   </parameterMap>               <!-- 查询操作 根据多个条件来查询时 需要配置perameterMap -->   <select id="getempbyjobandsal" parameterMap="empparameter" resultMap="empresult">       Select empno,ename,job,hiredate,sal,deptno From emp Where job=#{job} And Sal=#{sal}   </select>      <select id="getempbysal" parameterType="double" resultMap="empresult">       Select empno,ename,job,hiredate,sal,deptno From emp Where <![CDATA[sal<#{sql}]]>   </select>      <!-- 另外一种多个参数的方式 -->   <select id="getempbyenameandjob" parameterType="testmybatis.po.Emp" resultMap="empresult">       Select empno,ename,job,hiredate,sal,deptno From emp Where job=#{job} And ename=#{ename}   </select>      <!-- 添加操作 -->   <insert id="addemp" parameterType="testmybatis.po.Emp">           Insert Into emp(empno,ename,job,hiredate,sal,deptno) Values(#{empno},#{ename},#{job},#{hiredate},#{sal},#{deptno})   </insert>             <!-- 修改操作 -->   <update id="updateemp" parameterType="testmybatis.po.Emp">         Update emp Set sal=sal+#{sal} Where ename=#{ename}   </update>      <!-- 删除操作 -->   <delete id="deleteemp" parameterType="int">      delete from emp where empno=#{empno}   </delete>         <!-- 多表连接操作 -->   <select id="getempdept" resultMap="empdeptresult">        Select empno,ename,job,hiredate,sal,deptno,dname,loc From emp Natural Join dept   </select>      <resultMap type="testmybatis.po.Emp" id="empdeptresult">      <!-- id标示主键 -->      <id column="empno" property="empno" />       <result property="ename" column="ename" />       <result property="job" column="job" />       <result property="hiredate" column="hiredate" />       <result property="sal" column="sal" />       <result property="deptno" column="deptno" />              <!-- 必须配置dept的po文件 且在po.Emp当中关联po.Dept这个类 -->       <association property="dept" column="deptno" javaType="testmybatis.po.Dept" resultMap="deptresult"></association>   </resultMap>      <resultMap type="testmybatis.po.Dept" id="deptresult">      <id column="deptno" property="deptno"/>      <result column="dname" property="dname"/>      <result column="loc" property="loc"/>   </resultMap>               </mapper>