接上篇：
在搭建环境时已经有了mapper和sqlMapConfig
1,数据库建表
prompt PL/SQL Developer import fileprompt Created on 2018年6月1日 by Administratorset feedback offset define offprompt Creating T_USER...create table T_USER( T_NAME VARCHAR2(10) not null, T_PASS VARCHAR2(10), T_ID VARCHAR2(10));prompt Deleting T_USER...delete from T_USER;commit;prompt Loading T_USER...insert into T_USER (T_NAME, T_PASS, T_ID)values ('张三', 'zhangsan', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('王五', 'wangwu', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('小张', 'xiaozhang', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('刘雯2', 'liuwen2', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('刘雯', 'liuwen', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('王二麻子', 'wanger', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('刘雯1', 'liuwen1', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('刘雯3', 'liuwen3', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('王柳', 'liu', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('Jone', 'Jone', null);insert into T_USER (T_NAME, T_PASS, T_ID)values ('李四', 'lisi', null);commit;prompt 11 records loadedset feedback onset define onprompt Done.
2，导包
3，编写POJO
package com.songyan.pojo;public class Customer { private Integer id; //主键id private String username; //客户名称 private String job; //职业 private String phone; //电话 public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getJob() { return job; } public void setJob(String job) { this.job = job; } public String getPhone() { return phone; } public void setPhone(String phone) { this.phone = phone; } @Override public String toString() { // return "Customer [id=" + id + ",username=" + username + ",job=" + job + ",phone=" + phone + "]"; } } 3，与之对应的mapper
4，applicationcontext.xml
log4j.properties
log4j.appender.stdout=org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.Target=System.outlog4j.appender.stdout.layout=org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p [%t] %c{1}:%L - %m%n#\u5728\u5F00\u53D1\u73AF\u5883\u4E0B\u65E5\u5FD7\u7EA7\u522B\u8981\u8BBE\u7F6E\u6210DEBUG\uFF0C\u751F\u4EA7\u73AF\u5883\u8BBE\u7F6E\u6210info\u6216errorlog4j.rootLogger=DEBUG, stdout#log4j.rootLogger=stdout 5,测试类
package com.songyan.client;import java.io.IOException;import java.io.InputStream;import java.util.List;import javax.faces.application.Application;import javax.jms.Session;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import org.junit.Test;import com.songyan.pojo.Customer;public class Test1 { /** * 根据用户编号查询客户信息 * @throws IOException */ @Test public void selectCuById() throws IOException { //读取配置信息 String resource="applicationContext.xml"; //根据配置文件构建sqlsessionFactory InputStream in=Resources.getResourceAsStream(resource); //通过sqlsessionFactory创建sqlsession SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(in); SqlSession sqlSession =sqlSessionFactory.openSession(); //sqlsession执行sql并返回执行结果 Customer customer= sqlSession.selectOne("com.songyan.mapper.Customer.findCustomerById",1); //打印输出结果 System.out.println(customer); //关闭sqlsession sqlSession.close(); } /** * 根据用户名查询客户信息 * @throws IOException */ @Test public void findCustomerByName() throws IOException { //加载配置信息 String resource="applicationContext.xml"; //获取输入流 InputStream in=Resources.getResourceAsStream(resource); //获取工厂 SqlSessionFactory sessionFactory=new SqlSessionFactoryBuilder().build(in); //获取sqlsession对象 SqlSession sqlSession=sessionFactory.openSession(); //执行sql List customers=sqlSession.selectList("com.songyan.mapper.Customer.findCustomerByName","j"); //输出结果 for(Customer cu : customers) { System.out.println(cu); } //关闭sqlsession sqlSession.close(); } } 根据客户id查询的结果
根据客户name查询的结果
#{} 表示占位符，可以防止sql注入的问题，在执行sql的之后会自动补充单引号，他的参数可以任意的
${} 表示字符串的拼接 不可以防止sql的诸注入问题，在执行sql 的时候也没有任何添加符号，他的符号只能是value
当需要使用模糊查询，还要防止sql注入的时候可以使用下面的方式：
select * from user where username like "%"#{haha}"%" 使用#{}实现防止sql注入的问题
使用like "%"#{haha}"%"实现模糊查询
他表示的是包含haha的字段