用MyBatis通过SQL语句连接数据库代码：
一、创建User类：
package cn.tedu.domain;
import java.io.Serializable;
public class User implements Serializable{
private int id;
private String name;
private int age;
public User() {
}
public User(int id, String name, int age) {
this.id = id;
this.name = name;
this.age = age;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return “User [id=” + id + “, name=” + name + “, age=” + age + “]”;
}
}
二、创建UserMapper类：
package cn.tedu.Mapper;
import java.util.List;
import cn.tedu.domain.User;
public interface UserMapper {
public User selectOne(int id);
public List selectAll();
}
三、创建Test01测试类：
package cn.tedu.test;
import java.io.InputStream;
import java.util.List;
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 cn.tedu.Mapper.UserMapper;
import cn.tedu.domain.User;
public class Test01 {
@Test
public void test01() throws Exception {
//获取SqlSession
InputStream in = Resources.getResourceAsStream(“sqlMapConfig.xml”);
SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
SqlSession session = factory.openSession();
//获取Mapper
UserMapper userMapper = session.getMapper(UserMapper.class);
//调用方法
List list = userMapper.selectAll();
System.out.println(list);
User user = userMapper.selectOne(4);
System.out.println(user);
}
}
四、创建log4j配置文件:
log4j.rootLogger = debug,stdout
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%m%n
五、创建sqlMapConfig.xml配置：
<?xml version="1.0" encoding="utf-8"?> 六、创建userMapper.xml配置： <?xml version="1.0" encoding="UTF-8" ?> select * from user where id = #{id}; select * from user; 七、创建数据库： create database mybatisdb05; 八、创建表： use mybatisdb05; create table user( id int, name char(20), age int ); 九、插入数据： insert into user (id,name,age) values (1,'liaoliu',12), (2,'liaoliuliu',14), (3,'liaowen',16), (4,'liaoliu',12), (5,'liaoliuliu',14), (6,'liaowen',16);十、运行Test01类的test01方法得出结果：
[DEBUG] 2019-12-09 18:51:00,066 method:org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:132)> Preparing: select * from user;
[DEBUG] 2019-12-09 18:51:00,102 method:org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:132)> Parameters:
[User [id=1, name=liaoliu, age=12], User [id=2, name=liaoliuliu, age=14], User [id=3, name=liaowen, age=16], User [id=4, name=liaoliu, age=12], User [id=5, name=liaoliuliu, age=14], User [id=6, name=liaowen, age=16]]
[DEBUG] 2019-12-09 18:51:00,150 method:org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:132)ooo Using Connection [[email protected]]
[DEBUG] 2019-12-09 18:51:00,151 method:org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:132)> Preparing: select * from user where id = ?;
[DEBUG] 2019-12-09 18:51:00,152 method:org.apache.ibatis.logging.jdbc.BaseJdbcLogger.debug(BaseJdbcLogger.java:132)> Parameters: 4(Integer)
User [id=4, name=liaoliu, age=12]
用MyBatis通过SQL语句连接数据库图片：
工程目录：在这里插入图片描述
一、创建User类：
二、创建UserMapper类：
三、创建Test01测试类：
四、创建log4j配置文件:
五、创建sqlMapConfig.xml配置：
六、创建userMapper.xml配置：
七、创建数据库：
八、创建表：
九、插入数据：
十、运行Test01类的test01方法得出结果：
十一：数据库表