MyBatis中SqlSession实现增删改查案例

前言

     开博客这是第一次写系列文章，从内心上讲是有点担心自己写不好，写不全，毕竟是作为java/mybatis学习的过程想把学习的路线和遇到的问题都总结下来，也让知识点在脑海里能形成一个体系。

开发环境

    idea2016、mybatis3、sqlserver2012

pom.xml、mybatis.xml、log4j.properties

   先贴上pom.xml是因为他直接和搭建开发环境和测试环境有关系，mybatis.xml则是连接数据库，log4j.properties在学习阶段配置上有助于我们观察sql的执行情况。

1、pom.xml

<dependencies>
 <dependency>
  <groupid>org.mybatis</groupid>
  <artifactid>mybatis</artifactid>
  <version>3.4.2</version>
 </dependency>
 <dependency>
  <groupid>com.microsoft.sqlserver</groupid>
  <artifactid>sqljdbc4</artifactid>
  <version>4.0</version>
 </dependency>
 <dependency>
  <groupid>commons-dbcp</groupid>
  <artifactid>commons-dbcp</artifactid>
  <version>1.4</version>
 </dependency>
 <dependency>
  <groupid>junit</groupid>
  <artifactid>junit</artifactid>
  <version>4.10</version>
 </dependency>
 <dependency>
  <groupid>log4j</groupid>
  <artifactid>log4j</artifactid>
  <version>1.2.17</version>
 </dependency>
 </dependencies>

2、mybatis.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>

 <!-- mybatis针对sqlserver进行的配置 -->
 <typealiases>
  <typealias alias="user" type="com.autohome.model.user"/>
  <typealias alias="teacher" type="com.autohome.model.teacher" />
  <typealias alias="student" type="com.autohome.model.student" />
 </typealiases>
 <environments default="development">
  <environment id="development">
   <transactionmanager type="jdbc"/>
   <datasource type="pooled">
    <property name="driver" value="com.microsoft.sqlserver.jdbc.sqlserverdriver"/>
    <property name="url" value="jdbc:sqlserver://localhost:1433;databasename=test"/>
    <property name="username" value="sa"/>
    <property name="password" value="0"/>
   </datasource>
  </environment>
 </environments>


 <mappers>
  <mapper resource="mapper/user.xml"/>
  <mapper resource="mapper/student.xml"/>
 </mappers>
</configuration>

3、log4j.properties

### log4j配置 ###
### 与spring结合需要在web.xml中指定此文件位置，并添加监听器 ###
#定义log4j的输出级别和输出目的地（目的地可以自定义名称，和后面的对应）
#[ level ] , appendername1 , appendername2
log4j.rootlogger=debug,console,file

#-----------------------------------#
#1 定义日志输出目的地为控制台
log4j.appender.console = org.apache.log4j.consoleappender
log4j.appender.console.target = system.out
log4j.appender.console.threshold=debug
####可以灵活地指定日志输出格式，下面一行是指定具体的格式 ###
#%c: 输出日志信息所属的类目，通常就是所在类的全名
#%m: 输出代码中指定的消息,产生的日志具体信息
#%n: 输出一个回车换行符，windows平台为"/r/n"，unix平台为"/n"输出日志信息换行
log4j.appender.console.layout = org.apache.log4j.patternlayout
log4j.appender.console.layout.conversionpattern=[%c]-%m%n

#-----------------------------------#
#2 文件大小到达指定尺寸的时候产生一个新的文件
log4j.appender.file = org.apache.log4j.rollingfileappender
#日志文件输出目录
log4j.appender.file.file=log/tibet.log
#定义文件最大大小
log4j.appender.file.maxfilesize=10mb
###输出日志信息###
#最低级别
log4j.appender.file.threshold=error
log4j.appender.file.layout=org.apache.log4j.patternlayout
log4j.appender.file.layout.conversionpattern=[%p][%d{yy-mm-dd}][%c]%m%n

#-----------------------------------#
#3 druid
log4j.logger.druid.sql=info
log4j.logger.druid.sql.datasource=info
log4j.logger.druid.sql.connection=info
log4j.logger.druid.sql.statement=info
log4j.logger.druid.sql.resultset=info

#4 mybatis 显示sql语句部分
log4j.logger.org.mybatis=debug
#log4j.logger.cn.tibet.cas.dao=debug
#log4j.logger.org.mybatis.common.jdbc.simpledatasource=debug#
#log4j.logger.org.mybatis.common.jdbc.scriptrunner=debug#
#log4j.logger.org.mybatis.sqlmap.engine.impl.sqlmapclientdelegate=debug#
#log4j.logger.java.sql.connection=debug
log4j.logger.java.sql=debug
log4j.logger.java.sql.statement=debug
log4j.logger.java.sql.resultset=debug
log4j.logger.java.sql.preparedstatement=debug

配置mapper.xml

   mapper.xml在mybatis.xml是专职处理sql的一个环节，各种映射和实现都在这里处理

<?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.autohome.mapper.user">
 <!-- 查询全部用户 -->
 <select id="queryusers" resulttype="com.autohome.model.user">
  select * from t_userinfo
 </select>
 <!-- 按照id查询 -->
 <select id="queryuserbyid" parametertype="int" resulttype="com.autohome.model.user">
  select * from t_userinfo where id=#{id}
 </select>
 <select id="queryuserbyaddress" resulttype="com.autohome.model.user">
  select * from t_userinfo where name=#{name,javatype=string,jdbctype=varchar} and address=#{address}
 </select>
 <!-- 添加用户 -->
 <insert id="insertusers" parametertype="com.autohome.model.user">
  insert into t_userinfo (name,address) values(#{name},#{address})
 </insert>
 <!-- 修改用户 -->
 <update id="updateusers" parametertype="com.autohome.model.user">
  update t_userinfo set name=#{name},address=#{address} where id=#{id}
 </update>
 <!-- 删除用户 -->
 <delete id="deleteusers" parametertype="int">
  delete t_userinfo where id=#{id}
 </delete>
</mapper>

建立单元测试

1、准备工作，我建立的是控制台程序，所以在使用sqlsession前先创建sqlsessionfactory。当然，还要加载log4j.properties

sqlsessionfactory sqlsessionfactory=null;
 @before
 public void beforeclass(){
  try {
   inputstream is=resources.getresourceasstream("log4j.properties");
   propertyconfigurator.configure(is);
   reader reader = resources.getresourceasreader("mybatis.xml");
   sqlsessionfactory= new sqlsessionfactorybuilder().build(reader);
  } catch (ioexception e) {
   e.printstacktrace();
  }
 }

2、queryusers

@test
  public void queryusers() throws exception {
    //线程不安全类型，放在方法体内
    sqlsession sqlsession=null;
    try {
      sqlsession=sqlsessionfactory.opensession();
      list<user> list = sqlsession.selectlist("com.autohome.mapper.user.queryusers");
      system.out.println("size:"+list.size());
    } catch (exception e) {
      e.printstacktrace();
    }finally {
      sqlsession.close();
    }
  }

3、queryuserbyid

@test
  public void queryuserbyid() {
    sqlsession sqlsession=null;
    try{
      sqlsession=sqlsessionfactory.opensession();
      user user = sqlsession.selectone("com.autohome.mapper.user.queryuserbyid",2);
      system.out.println("id:"+user.getid()+",name:"+user.getname()+","+user.getaddress());
    }catch(exception e){
      e.printstacktrace();
    }finally {
      sqlsession.close();
    }
  }

4、insertuser

@test
  public void insertuser(){
    sqlsession sqlsession=null;
    try{
      sqlsession=sqlsessionfactory.opensession();
      user user =new user();
      user.setname("kobe");
      user.setaddress("usa");
      int result = sqlsession.insert("com.autohome.mapper.user.insertusers",user);
      sqlsession.commit();
      if(result>0){
        system.out.println("insert success....");
      }else{
        system.out.println("insert error....");
      }
    }catch(exception e){
      e.printstacktrace();
    }finally {
      sqlsession.close();
    }
  }

5、updateuser

@test
 public void updateuser(){
   sqlsession sqlsession=null;
   try{
     sqlsession=sqlsessionfactory.opensession();
     user user =new user();
     user.setid(36);
     user.setname("kobe");
     user.setaddress("usa");
     int result = sqlsession.update("com.autohome.mapper.user.updateusers",user);
     sqlsession.commit();
     if(result>0){
       system.out.println("update success....");
     }else{
       system.out.println("update error....");
     }
   }catch(exception e){
     e.printstacktrace();
   }finally {
     sqlsession.close();
   }
 }

6、deleteuser

@test
  public void deleteuser(){
    sqlsession sqlsession=null;
    try{
      sqlsession=sqlsessionfactory.opensession();
      int result = sqlsession.delete("com.autohome.mapper.user.deleteusers",49);
      sqlsession.commit();
      if(result>0){
        system.out.println("delete success....");
      }else{
        system.out.println("delete error....");
      }
    }catch(exception e){
      e.printstacktrace();
    }finally {
      sqlsession.close();
    }
  }

总结

      添加、修改、删除的操作要调用sqlsession.commit(),不然数据无法入库的，我刚开始就忘记了这个。

以上所述是小编给大家介绍的mybatis中sqlsession实现增删改查案例，希望对大家有所帮助