MyBatis三个查询方法_selectList_selectOne

mybatis-cfg.xml的配置：

<?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>

  <!-- properties加载配置文件

   -->

  <properties resource="db.properties"></properties>

  <settings>

  	<setting name="logImpl" value="LOG4J"/>

  </settings>

  	<environments default="dev">

 		<environment id="dev">

 			<transactionManager type="JDBC"/>

 			<dataSource type="POOLED">

 				<property name="driver" value="${jdbc.driver}"/>

 				<property name="url" value="${jdbc.url}"/>

 				<property name="username" value="${jdbc.username}"/>

 				<property name="password" value="${jdbc.password}"/>

 			</dataSource>

 		</environment>

  	</environments>

  	<mappers >

  		<mapper resource="com/bjsxt/mapper/UserMapper.xml"/>

  	</mappers>

  </configuration>

db.properties:

jdbc.driver=com.mysql.jdbc.Driver

jdbc.url=jdbc:mysql://192.168.5.129:3306/bjsxt

jdbc.username=root

jdbc.password=root

log4j.properties:

# Set root category priority to INFO and its only appender to CONSOLE.

log4j.rootCategory=info, CONSOLE

# log4j.rootCategory=DEBUG, CONSOLE, LOGFILE

# 单独设置SQL语句的输出级别为DEBUG级别

# 方法级别

# log4j.logger.com.bjsxt.mapper.UserMapper.selAll=DEBUG

# 类级别

# log4j.logger.com.bjsxt.mapper.UserMapper=DEBUG

# 包级别

log4j.logger.com.bjsxt.mapper=DEBUG

# CONSOLE is set to be a ConsoleAppender using a PatternLayout.

log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender

log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout

log4j.appender.CONSOLE.layout.ConversionPattern=- %m%l%n

# LOGFILE is set to be a File appender using a PatternLayout.

log4j.appender.LOGFILE=org.apache.log4j.FileAppender

log4j.appender.LOGFILE.File=d:/test.log

log4j.appender.LOGFILE.Append=true

log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout

log4j.appender.LOGFILE.layout.ConversionPattern=- %m %l%n

User实体类

package com.bjsxt.pojo;

import java.io.Serializable;

public class User implements Serializable{

	private int id;

	private String username;

	private String password;

	public int getId() {

		return id;

	}

	public void setId(int id) {

		this.id = id;

	}

	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;

	}

	@Override

	public String toString() {

		return "User [id=" + id + ", username=" + username + ", password=" + password + "]";

	}

	@Override

	public int hashCode() {

		final int prime = 31;

		int result = 1;

		result = prime * result + id;

		result = prime * result + ((password == null) ? 0 : password.hashCode());

		result = prime * result + ((username == null) ? 0 : username.hashCode());

		return result;

	}

	@Override

	public boolean equals(Object obj) {

		if (this == obj)

			return true;

		if (obj == null)

			return false;

		if (getClass() != obj.getClass())

			return false;

		User other = (User) obj;

		if (id != other.id)

			return false;

		if (password == null) {

			if (other.password != null)

				return false;

		} else if (!password.equals(other.password))

			return false;

		if (username == null) {

			if (other.username != null)

				return false;

		} else if (!username.equals(other.username))

			return false;

		return true;

	}

	public User() {

		super();

	}

}

selectList_selectOne_selectMap:

<?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.bjsxt.mapper.UserMapper">

  	<select id="sellAll" resultType="com.bjsxt.pojo.User">

  		select * from t_user

  	</select>

  	<select id="sellOne" resultType="com.bjsxt.pojo.User">

  		select * from t_user where id=2

  	</select>

  </mapper>

package com.bjsxt.TestSelect;

import java.io.IOException;

import java.io.InputStream;

import java.util.List;

import java.util.Map;

import java.util.Set;

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.bjsxt.pojo.User;

public class TestSelect {

	@Test

	public void testSelectList() throws IOException {

		InputStream is = Resources.getResourceAsStream("mybatis-cfg.xml");

		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);

		SqlSession session = factory.openSession();

		List<User> list = session.selectList("com.bjsxt.mapper.UserMapper.sellAll");

		for (User user : list) {

			System.out.println(user);

		}

		session.close();

	}

	@Test

	public void testSelectOne() throws IOException {

		InputStream is = Resources.getResourceAsStream("mybatis-cfg.xml");

		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);

		SqlSession session = factory.openSession();

		User u = session.selectOne("com.bjsxt.mapper.UserMapper.sellOne");

		System.out.println(u);

		session.close();

	}

	@Test

	public void testSelectMap() throws IOException {

		InputStream is = Resources.getResourceAsStream("mybatis-cfg.xml");

		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);

		SqlSession session = factory.openSession();

		Map<Integer, User> map = session.selectMap("com.bjsxt.mapper.UserMapper.sellAll", "id");

		Set<Integer> ks = map.keySet();

		for (Integer k : ks) {

			System.out.println(map.get(k));

		}

		session.close();

	}

}

巴特西

MyBatis三个查询方法_selectList_selectOne_selectMap

selectList_selectOne_selectMap:

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