package cn.happy.dao;import java.util.List;import cn.happy.entity.Dept;public interface IDeptDao {//查看全部---------getAllDept要和小配置里面的id一樣public List<Dept> getAllDept();}

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="cn.happy.dao.IDeptDao"><select id="getAllDept" resultType="cn.happy.entity.Dept">select * from Dept </select></mapper>

// 01查看全部信息getMapper()接口類的方法名要和小配置的id一樣@Testpublic void testSelectAll() {SqlSession session = factory.openSession();//用的是弱類型========實體類.小配置里面的Id名稱============字符串/*List<Dept> list = session.selectList("cn.happy.dao.IDeptDao.getAllDept");for (Dept dept : list) {System.out.println(dept.getDeptName());}*/// 用getMapper方法HIbernate幫我們在內(nèi)存中代理出一個接口的實現(xiàn)類======相當于強類型//mapper是一個實現(xiàn)類對象IDeptDao mapper = session.getMapper(IDeptDao.class);List<Dept> list = mapper.getAllDept();for (Dept dept : list) {System.out.println(dept.getDeptName());}

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration><!-- Alias別名 小配置里面的type的屬性值改成別名--><typeAliases><typeAlias type="cn.resultMap.enetity.Emp" alias="emp"/></typeAliases><environments default="development"><environment id="development"><transactionManager type="JDBC" /><dataSource type="POOLED"><property name="driver" value="oracle.jdbc.OracleDriver" /><property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" /><property name="username" value="sa" /><property name="password" value="1" /></dataSource></environment></environments><!--映射文件：描述某個實體和數(shù)據(jù)庫表的對應關(guān)系 --><mappers><mapper resource="cn/resultMap/enetity/Emp.xml" /></mappers></configuration>

package cn.resultMap.dao;import java.util.List;import cn.resultMap.enetity.Emp;public interface IEmpDao {//檢索所有員工，以及隸屬部門public List<Emp> getAllEmps();}

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="cn.resultMap.dao.IEmpDao"><resultMap type="cn.resultMap.enetity.Emp" id="empMap"><id property="empId" column="EMPID"/><result property="empName" column="EMPNAME"/><result property="empCity" column="EMPCITY"/><!-- 員工角度 多的一方，嵌入一的一方的各個屬性請使用association --><association property="dept" javaType="cn.resultMap.enetity.Dept"><result property="deptName" column="DEPTNAME"/><result property="deptNo" column="DEPTNO"/></association></resultMap><select id="getAllEmps" resultMap="empMap">select e.*,d.* from Emp e,Dept dwhere e.deptNo=d.deptNo</select></mapper>

//resultMap:實體的屬性名和表的字段名保證一致用resultMap//如果報NullException查看小配置的映射關(guān)聯(lián)resultMap是否配置@Testpublic void testAllEmp(){SqlSession session=factory.openSession();IEmpDao mapper = session.getMapper(IEmpDao.class);List<Emp> allEmps = mapper.getAllEmps();for (Emp emp : allEmps) {System.out.println(emp.getEmpName()+"/t隸屬部門"+emp.getDept().getDeptName());}session.close();}

<!-- SQl標簽的使用 --><sql id="columns">d.deptNo,d.deptName</sql><!-- SQl標簽的使用 --><select id="getAllEmps" resultMap="empMap">select e.*,<include refid="columns"/>from Emp e,Dept dwhere e.deptNo=d.deptNo</select>

<!-- Alias別名 小配置里面的type的屬性值改成別名--><typeAliases><typeAlias type="cn.resultMap.enetity.Emp" alias="emp"/></typeAliases>

　if　　　　choose(when,otherwise)　　　　where 　　　　set 

package cn.resultMap.dao;import java.util.List;import cn.resultMap.enetity.Emp;public interface IEmpDao {//檢索所有員工，以及隸屬部門public List<Emp> getAllEmps();}

<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="cn.resultMap.dao.IEmpDao"><resultMap type="cn.resultMap.enetity.Emp" id="empMap"><id property="empId" column="EMPID"/><result property="empName" column="EMPNAME"/><result property="empCity" column="EMPCITY"/><!-- 員工角度 多的一方，嵌入一的一方的各個屬性請使用association --><association property="dept" javaType="cn.resultMap.enetity.Dept"><result property="deptName" column="DEPTNAME"/><result property="deptNo" column="DEPTNO"/></association></resultMap><select id="getAllEmps" resultMap="empMap">select e.*,d.* from Emp e,Dept dwhere e.deptNo=d.deptNo</select><!--查詢動態(tài)查詢 --><select id="testAllEmpBuSelect" parameterType="cn.resultMap.enetity.Emp" resultType="cn.resultMap.enetity.Emp">select * from Emp<where><if test="empId!=null">and empId=#{empId}</if><if test="empName!=null">and empName=#{empName}</if><if test="empCity!=null">and empCity=#{empCity}</if></where></select></mapper>

//動態(tài)查詢@Testpublic void testSelect(){SqlSession session=factory.openSession();Emp emp=new Emp();//emp.setEmpName("331");emp.setEmpCity("sh");List<Emp> list = session.selectList("cn.resultMap.dao.IEmpDao.testAllEmpBuSelect",emp);for (Emp emps : list) {System.out.println(emps.getEmpName());}session.close();}

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="cn.resultMap.dao.IDeptDao"><resultMap type="cn.happy.entity.Dept" id="deptResultMap"><id property="deptNo" column="deptNo"/><result property="deptName" column="deptName"/></resultMap><select id="getAllDept" resultMap="deptResultMap">select d.*，e.* from Dept d,Emp ewhere d.deptNo=e.deptNo and d.deptNo=#{deptNo}</select><!--修改動態(tài)查詢 --><select id="testUpdate" parameterType="int" resultType="cn.resultMap.enetity.Dept">update dept<set><if test="deptNo!=null">deptNo=#{deptNo},</if><if test="deptName!=null">deptName=#{deptName},</if></set>where deptNo=#{deptNo}</select></mapper> 

/*** 動態(tài)修改* */@Testpublic void testUpdate(){SqlSession session=factory.openSession();Dept dept=new Dept();dept.setDeptName("財務部");dept.setDeptNo(1);int count = session.update("cn.resultMap.dao.IDeptDao.testUpdate",dept);session.commit();System.out.println(count);session.close();}