[置顶] Mybatis基本应用实现增删改查
1.概述
Mybatis在以数据库为中心的项目中很常用，最近本的操作就是对数据表的增删改查。本文直接以Mybatis+MySql数据库为例，实现增删查。尽量不去讲太多概念，力求简单易懂。
2.搭建环境工具
首先安装MySQl；安装Eclipse；这些不是本文重点，相信大家都会。
3.建立工程结构如下：
![[置顶] Mybatis基本应用实现增删改查_第1张图片](http://img.e-com-net.com/image/info5/8616ef774a0c407e95bc5002020d2712.png)
1）需要的jar包
| mybatis-3.0.5.jar |
Mybatis访问数据库 |
| mysql-connector-java-5.1.25-bin.jar |
连接mysql数据库用 |
| log4j-1.2.13.jar slf4j-api-1.5.8.jar slf4j-log4j12-1.5.8.jar |
日志记录用 |
2）Mybatis配置
<?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> <!-- 配置别名 --> <typeAliases> <typeAlias type="com.iMybatis.use.dao.UserDao" alias="UserDao" /> <typeAlias type="com.iMybatis.model.UserDto" alias="UserDto" /> </typeAliases> <!-- 配置环境变量 --> <environments default="development"> <environment id="development"> <transactionManager type="JDBC" /> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:mysql://127.0.0.1:3306/iMybatis" /> <property name="username" value="root" /> <property name="password" value="1" /> </dataSource> </environment> </environments> <!-- 配置mappers --> <mappers> <mapper resource="com/iMybatis/use/dao/UserDao.xml" /> </mappers> </configuration>
3）日志配置
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="console" class="org.apache.log4j.ConsoleAppender">
<!-- <param name="Target" value="System.out" /> -->
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss,SSS} %-5p %c - %m%n" />
</layout>
</appender>
<appender name="file" class="org.apache.log4j.RollingFileAppender" >
<param name="File" value="iMybatis.log" />
<param name="MaxFileSize" value="100KB" />
<param name="MaxBackupIndex" value="2" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="=%d %-5p [%t] %-17c{2} (%13F:%L) %3x - %m%n" />
</layout>
</appender>
<category name="org.apache.ibatis" additivity="false">
<priority value="DEBUG" />
<appender-ref ref="console" />
</category>
<category name="java.sql" additivity="false">
<priority value="ERROR" />
<appender-ref ref="console" />
</category>
<logger name="org.apache.ibatis.common.jdbc.SimpleDataSource">
<level value="debug" />
</logger>
<logger name="org.apache.ibatis.common.jdbc.SimpleDataSource">
<level value="debug" />
</logger>
<logger name="org.apache.ibatis.common.jdbc.ScriptRunner">
<level value="debug" />
</logger>
<logger name="org.apache.ibatis.common.jdbc.SqlMapClientDelegate">
<level value="debug" />
</logger>
<logger name="java.sql.Connection">
<level value="debug" />
</logger>
<logger name="java.sql.Statement">
<level value="debug" />
</logger>
<logger name="java.sql.PreparedStatement">
<level value="debug" />
</logger>
<logger name="java.sql.ResultSet">
<level value="debug" />
</logger>
<root>
<priority value="ERROR" />
<appender-ref ref="console" />
</root>
</log4j:configuration>
4）数据库访问DAO
package com.iMybatis.use.dao;
import java.util.List;
import com.iMybatis.model.UserDto;
public interface UserDao {
public List<UserDto> queryUsers(UserDto user) throws Exception;
public int addUser(UserDto user) throws Exception;
public int deleteUser(UserDto user) throws Exception;
public int updateUser(UserDto user) throws Exception;
public List<UserDto> getAllUsers(UserDto user) throws Exception;
}
sqlmap配置代码
<?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.iMybatis.use.dao.UserDao">
<select id="queryUsers" parameterType="UserDto" resultType="UserDto"
useCache="false">
<![CDATA[
select * from t_user t where t.username = #{username}
]]>
</select>
<!-- 创建用户(Create) -->
<insert id="addUser" parameterType="UserDto">
insert into t_user(username,password,address) values(#{username},#{password},#{address})
</insert>
<!-- 删除用户(Remove) -->
<delete id="deleteUser" parameterType="int">
delete from t_user where userid=#{userid}
</delete>
<!-- 修改用户(Update) -->
<update id="updateUser" parameterType="UserDto">
update t_user set username=#{username},password=#{password},address=#{address} where userid=#{userid}
</update>
<!-- 查询全部用户-->
<select id="getAllUsers" resultType="UserDto">
select * from t_user
</select>
</mapper>
5）实体类
package com.iMybatis.model;
public class UserDto {
private Integer userid;
private String username;
private String password;
private String address;
private String createtime;
public Integer getUserid() {
return userid;
}
public void setUserid(Integer userid) {
this.userid = userid;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getCreatetime() {
return createtime;
}
public void setCreatetime(String createtime) {
this.createtime = createtime;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
6）测试类
package com.iMybatis.use;
import java.io.IOException;
import java.io.Reader;
import java.util.List;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.logging.Log;
import org.apache.ibatis.logging.LogFactory;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import com.iMybatis.model.UserDto;
import com.iMybatis.use.dao.UserDao;
public class useMybatis
{
private static final Log logger = LogFactory.getLog(useMybatis.class);
private static SqlSessionFactoryBuilder sqlSessionFactoryBuilder;
private static SqlSessionFactory sqlSessionFactory;
public static void main(String[] args) {
// TODO Auto-generated method stub
try
{
System.out.println("测试");
init();
}
catch (IOException e)
{
logger.error("", e);
}
testQueryList();//查询
//testAddUser(); // 增加
//testUpdateUser();// 修改
//testDeleteUser();// 删除
}
private static void init() throws IOException {
String resource = "mybatis-config.xml";
// System.out.println(resource);
Reader reader = Resources.getResourceAsReader(resource);
System.out.println(reader);
sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
sqlSessionFactory = sqlSessionFactoryBuilder.build(reader);
}
private static void testQueryList() {
SqlSession session = null;
try
{
session = sqlSessionFactory.openSession();
UserDao userDao = session.getMapper(UserDao.class);
UserDto user = new UserDto();
user.setUsername("iMbatis");
List<UserDto> users = userDao.queryUsers(user);
if (null != users)
{
logger.error("Find " + users.size() + " users named iMbatis.");
}
session.commit(true);
}
catch (Exception e)
{
logger.error("", e);
session.rollback(true);
}
finally
{
session.close();
}
}
private static void testAddUser() {
SqlSession session = null;
try
{
session = sqlSessionFactory.openSession();
UserDao userDao = session.getMapper(UserDao.class);
for (int k = 0; k < 10; k++)
{
UserDto user = new UserDto();
user.setUsername("zhang" + k);
user.setAddress("bei" + k);
userDao.addUser(user);
logger.error("添加" + String.valueOf(k));
}
session.commit(true);
}
catch (Exception e)
{
logger.error("", e);
session.rollback(true);
}
finally
{
session.close();
}
}
private static void testUpdateUser() {
SqlSession session = null;
try
{
session = sqlSessionFactory.openSession();
UserDao userDao = session.getMapper(UserDao.class);
UserDto user = new UserDto();
user.setUserid(6);
user.setUsername("zhang6");
user.setPassword("ps");
user.setAddress("beijing");
userDao.updateUser(user);
int retResult = userDao.updateUser(user);
logger.error("修改测试"+retResult);
session.commit(true);
}
catch (Exception e)
{
logger.error("", e);
session.rollback(true);
}
finally
{
session.close();
}
}
private static void testDeleteUser() {
SqlSession session = null;
try
{
session = sqlSessionFactory.openSession();
UserDao userDao = session.getMapper(UserDao.class);
UserDto user = new UserDto();
user.setUserid(7);
int retResult =userDao.deleteUser(user);
logger.error("删除测试"+retResult);
session.commit(true);
}
catch (Exception e)
{
logger.error("", e);
session.rollback(true);
}
finally
{
session.close();
}
}
}
4总结
访问数据库本质都是：1打开数据库连接；2执行SQL；3关闭数据库连接；
5.代码
下载代码