MyBatis.3.CRUD
【摘要】
<?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...
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
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"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
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<mapper namespace="org.mybatis.example.dao.DeptMapper">
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<select id="selectOne" parameterType="int"
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resultType="org.mybatis.example.dao.Dept">
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select * from dept where deptno=#{id}
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</select>
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<insert id="insertDept" parameterType="org.mybatis.example.dao.Dept"
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useGeneratedKeys="true" keyProperty="dept">
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insert into dept(dname,loc)
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values(
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#{dname,jdbcType=VARCHAR},
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#{loc,jdbcType=VARCHAR})
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</insert>
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<update id="updateDept" parameterType="org.mybatis.example.dao.Dept">
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update dept set dname=#{dname},loc=#{loc}
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where deptno=#{deptno}
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</update>
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<delete id="deleteDept" parameterType="java.lang.Integer">
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delete from dept where deptno=#{id}
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</delete>
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</mapper>
JAVA就业套餐课：https://edu.csdn.net/combo/detail/1230
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package org.mybatis.example.dao;
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public interface DeptMapper {
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public Dept selectOne(int id);
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public int insertDept(Dept dept);
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public int updateDept(Dept dept);
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public int deleteDept(int id);
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}
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import java.io.IOException;
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import java.io.Reader;
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import org.apache.ibatis.io.Resources;
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import org.apache.ibatis.session.SqlSession;
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import org.apache.ibatis.session.SqlSessionFactory;
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import org.apache.ibatis.session.SqlSessionFactoryBuilder;
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import org.mybatis.example.dao.Dept;
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import org.mybatis.example.dao.DeptMapper;
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public class Test2 {
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public static void main(String[] args) throws IOException {
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String resource="mybatisConfig.xml";
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Reader reader=Resources.getResourceAsReader(resource);
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SqlSessionFactory sqlMapper=new SqlSessionFactoryBuilder().build(reader);
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SqlSession session=sqlMapper.openSession();
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try {
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DeptMapper mapper=session.getMapper(DeptMapper.class);
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//1.查询
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// Dept dept=mapper.selectOne(2);
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// System.out.println(dept.getDname());
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//2.插入操作
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Dept dept=new Dept();
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dept.setDname("张沅湲");
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dept.setLoc("郑州");
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mapper.insertDept(dept);
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session.commit();//实现增加 修改 删除
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//3.更新操作;
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// Dept dept=new Dept();
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// dept.setDeptno(3);
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// dept.setDname("张沅湲");
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// dept.setLoc("湖南");
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// mapper.updateDept(dept);
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// session.commit();
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//4.删除操作;
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// int i=mapper.deleteDept(3);
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// session.commit();
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// System.out.println(i);
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} catch (Exception e) {
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e.printStackTrace();
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}finally{
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session.close();
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}
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}
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}
复杂的查询，在项目开发中，可以使用一个工具类来封装这些复杂的步骤：
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package org.mybatis.example.dao;
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import java.io.Reader;
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import org.apache.ibatis.io.Resources;
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import org.apache.ibatis.session.SqlSession;
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import org.apache.ibatis.session.SqlSessionFactory;
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import org.apache.ibatis.session.SqlSessionFactoryBuilder;
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public class SqlSessionFactoryUtil {
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private static SqlSessionFactory factory;
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public SqlSessionFactoryUtil() {}
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static{
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Reader reader=null;
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try {
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reader=Resources.getResourceAsReader("mybatisConfig.xml");
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factory=new SqlSessionFactoryBuilder().build(reader);
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} catch (Exception e) {
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e.printStackTrace();
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}finally{
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try {
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if(reader!=null)reader.close();
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} catch (Exception e2) {
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e2.printStackTrace();
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}
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}
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}
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public static SqlSession getSqlSession(){
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return factory.openSession();
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}
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}
DeptMapper接口的完全代码：
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package org.mybatis.example.dao;
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import java.util.List;
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public interface DeptMapper {
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public Dept selectOne(int id);
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public int insertDept(Dept dept);
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public int updateDept(Dept dept);
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public int deleteDept(int id);
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public List<Dept>selectAllDepts();
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public List<Dept>selectByCriteria(String deptName);
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}
1.查询所有部门信息参考代码;
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<select id="selectAllDepts" resultType="org.mybatis.example.dao.Dept" >
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select deptno,dname,loc from dept
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</select>
测试代码；
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import java.util.List;
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import org.apache.ibatis.session.SqlSession;
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import org.mybatis.example.dao.Dept;
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import org.mybatis.example.dao.DeptMapper;
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import org.mybatis.example.dao.SqlSessionFactoryUtil;
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public class Test3 {
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public static void main(String[] args) {
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SqlSession session=SqlSessionFactoryUtil.getSqlSession();
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try {
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DeptMapper mapper=session.getMapper(DeptMapper.class);
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List<Dept>depts=mapper.selectAllDepts();
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for(Dept dept:depts){
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System.out.println("部门名称:"+dept.getDname());
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}
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} catch (Exception e) {
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e.printStackTrace();
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}finally{
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session.close();
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}
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}
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}
2.按条件查询，映射文件做以下修改，新增条件为模糊查询方法：
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<!-- 按条件查询 -->
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<select id="selectByCriteria" parameterType="java.lang.String"
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resultType="org.mybatis.example.dao.Dept">
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select deptno,dname,loc from dept
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where dname like '%${_parameter}%'
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</select>
测试代码
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import java.util.List;
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import org.apache.ibatis.session.SqlSession;
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import org.mybatis.example.dao.Dept;
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import org.mybatis.example.dao.DeptMapper;
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import org.mybatis.example.dao.SqlSessionFactoryUtil;
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//按照条件进行查询;
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public class Test4 {
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public static void main(String[] args) {
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SqlSession session=SqlSessionFactoryUtil.getSqlSession();
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try {
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DeptMapper mapper=session.getMapper(DeptMapper.class);
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List<Dept>depts=mapper.selectByCriteria("网络部");
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for(Dept dept:depts){
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System.out.println("部门名称:"+dept.getDname());
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}
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} catch (Exception e) {
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e.printStackTrace();
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}finally{
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session.close();
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}
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}
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}
文章来源: aaaedu.blog.csdn.net，作者：tea_year，版权归原作者所有，如需转载，请联系作者。
原文链接：aaaedu.blog.csdn.net/article/details/54910360
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