mybatisPlus实现CRUD

简介：

1.MyBatis-Plus,它是一个MyBatis的增强工具包，是简化MyBatis开发工作。

2.资料地址:

官方地址：https://mp.baomidou.com/

资料地址：https://baomidou.gitee.io/mybatis-plus-doc/#/

文档地址：https://baomidou.gitee.io/mybatis-plus-doc/#/quick-start

集成MybatisPlus：

1.创建数据库表

mybatisPlus实现CRUD

2.创建实体类

@TableName(value=”tablename”)与数据库表明一致

@TableId(value=””,type=IdType.auto)实体类与数据库id一致的话就不用配括号里的值

@tableFiled(value=”columnName”,exist=false)数据库别的字段

package cn.xxs.pojo;

import java.util.Date;
import java.util.List;

import com.baomidou.mybatisplus.annotations.TableField;
import com.baomidou.mybatisplus.annotations.TableId;
import com.baomidou.mybatisplus.annotations.TableName;
/**
 * 学生实体类
 * @author xxs
 */
@TableName(value="tblstudent")
public class Student {
	
	@TableId
	private Integer studentId;//学生编号
	@TableField
	private String studentName;//学生姓名
	private Integer age;//年龄
	private String studentNo;//学号
	private Date birthDay;//生日
	public Student() {
		super();
		// TODO Auto-generated constructor stub
	}
	public Student(Integer studentId, String studentName, Integer age, String studentNo, Date birthDay) {
		super();
		this.studentId = studentId;
		this.studentName = studentName;
		this.age = age;
		this.studentNo = studentNo;
		this.birthDay = birthDay;
	}
	public Integer getStudentId() {
		return studentId;
	}
	public void setStudentId(Integer studentId) {
		this.studentId = studentId;
	}
	public String getStudentName() {
		return studentName;
	}
	public void setStudentName(String studentName) {
		this.studentName = studentName;
	}
	public Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	public String getStudentNo() {
		return studentNo;
	}
	public void setStudentNo(String studentNo) {
		this.studentNo = studentNo;
	}
	public Date getBirthDay() {
		return birthDay;
	}
	public void setBirthDay(Date birthDay) {
		this.birthDay = birthDay;
	}
	@Override
	public String toString() {
		return "Student [studentId=" + studentId + ", studentName=" + studentName + ", age=" + age + ", studentNo="
				+ studentNo + ", birthDay=" + birthDay + "]";
	}
	
}

3、添加依赖

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>cn.xxs</groupId>
  <artifactId>spring_mybitsPlus</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <properties>
		<!-- jdk版本 -->
		<java-version>1.8</java-version>
		<!-- spring版本 -->
		<org.springframework-version>4.3.7.RELEASE</org.springframework-version>
		<!-- 切点版本 -->
		<org.aspectj-version>1.8.1</org.aspectj-version>
		<!-- 日志版本 -->
		<org.slf4j-version>1.6.6</org.slf4j-version>
		<!-- mybatis版本 -->
		<org.mybatis-version>3.2.8</org.mybatis-version>
		<!-- mysql连接版本 -->
		<mysql-version>5.1.45</mysql-version>
		<!-- jackson版本 -->
		<jackson-version>2.9.4</jackson-version>
	</properties>
	<dependencies>	
	<!-- mybatisplus依赖 -->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus</artifactId>
			<version>2.3</version>
		</dependency>	
		<!-- Spring -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-context</artifactId>
			<version>${org.springframework-version}</version>
			<exclusions>
				<!-- Exclude Commons Logging in favor of SLF4j -->
				<exclusion>
					<groupId>commons-logging</groupId>
					<artifactId>commons-logging</artifactId>
				 </exclusion>
			</exclusions>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-aop</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-aspects</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-beans</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
				<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-context-support</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-core</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-expression</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>	
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-instrument</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-instrument-tomcat</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-jdbc</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
				<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-jms</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>	
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-messaging</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
				<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-orm</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-oxm</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
				<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-test</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-tx</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
				<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-web</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc-portlet</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-websocket</artifactId>
			<version>${org.springframework-version}</version>
		</dependency>
												
		<!-- AspectJ -->
		<dependency>
			<groupId>org.aspectj</groupId>
			<artifactId>aspectjrt</artifactId>
			<version>1.8.9</version>
		</dependency>	
		<dependency>
			<groupId>org.aspectj</groupId>
			<artifactId>aspectjweaver</artifactId>
			<version>1.8.1</version>
		</dependency>
		
		<!-- commons -->
		<dependency>
			<groupId>commons-dbcp</groupId>
			<artifactId>commons-dbcp</artifactId>
			<version>1.4</version>
		</dependency>
		<dependency>
			<groupId>commons-fileupload</groupId>
			<artifactId>commons-fileupload</artifactId>
			<version>1.3.1</version>
		</dependency>	
		<dependency>
			<groupId>commons-io</groupId>
			<artifactId>commons-io</artifactId>
			<version>2.5</version>
		</dependency>					
		<dependency>
			<groupId>commons-logging</groupId>
			<artifactId>commons-logging</artifactId>
			<version>1.2</version>
		</dependency>	
		<dependency>
			<groupId>commons-net</groupId>
			<artifactId>commons-net</artifactId>
			<version>3.3</version>
		</dependency>
		<dependency>
			<groupId>commons-pool</groupId>
			<artifactId>commons-pool</artifactId>
			<version>1.5.5</version>
		</dependency>
		
		<!-- json -->
 		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-annotations</artifactId>
			<version>${jackson-version}</version>
		</dependency>
 		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-core</artifactId>
			<version>${jackson-version}</version>
		</dependency>
 		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-databind</artifactId>
			<version>${jackson-version}</version>
		</dependency>
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>fastjson</artifactId>
			<version>1.2.23</version>
		</dependency>
		<!-- jstl标签库 -->
 		<dependency>
			<groupId>jstl</groupId>
			<artifactId>jstl</artifactId>
			<version>1.2</version>
		</dependency>
		
		<!-- mybatis -->
 		<!-- <dependency>
			<groupId>org.mybatis</groupId>
			<artifactId>mybatis</artifactId>
			<version>3.2.8</version>
		</dependency>
 		<dependency>
			<groupId>org.mybatis</groupId>
			<artifactId>mybatis-spring</artifactId>
			<version>1.2.2</version>
		</dependency> -->
						
		<!-- mysql -->
 		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>${mysql-version}</version>
		</dependency>
																
		<!-- Logging -->
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-api</artifactId>
			<version>${org.slf4j-version}</version>
		</dependency>
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>jcl-over-slf4j</artifactId>
			<version>${org.slf4j-version}</version>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-log4j12</artifactId>
			<version>${org.slf4j-version}</version>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>log4j</groupId>
			<artifactId>log4j</artifactId>
			<version>1.2.17</version>
			<exclusions>
				<exclusion>
					<groupId>javax.mail</groupId>
					<artifactId>mail</artifactId>
				</exclusion>
				<exclusion>
					<groupId>javax.jms</groupId>
					<artifactId>jms</artifactId>
				</exclusion>
				<exclusion>
					<groupId>com.sun.jdmk</groupId>
					<artifactId>jmxtools</artifactId>
				</exclusion>
				<exclusion>
					<groupId>com.sun.jmx</groupId>
					<artifactId>jmxri</artifactId>
				</exclusion>
			</exclusions>
			<scope>runtime</scope>
		</dependency>

		<!-- @Inject -->
		<dependency>
			<groupId>javax.inject</groupId>
			<artifactId>javax.inject</artifactId>
			<version>1</version>
		</dependency>
				
		<!-- Servlet -->
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>servlet-api</artifactId>
			<version>2.5</version>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>javax.servlet.jsp</groupId>
			<artifactId>jsp-api</artifactId>
			<version>2.1</version>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>jstl</artifactId>
			<version>1.2</version>
		</dependency>
	
		<!-- Test -->
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.7</version>
			<scope>test</scope>
		</dependency>  
		
		
		      
	</dependencies>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-eclipse-plugin</artifactId>
                <version>2.9</version>
                <configuration>
                    <additionalProjectnatures>
                        <projectnature>org.springframework.ide.eclipse.core.springnature</projectnature>
                    </additionalProjectnatures>
                    <additionalBuildcommands>
                        <buildcommand>org.springframework.ide.eclipse.core.springbuilder</buildcommand>
                    </additionalBuildcommands>
                    <downloadSources>true</downloadSources>
                    <downloadJavadocs>true</downloadJavadocs>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <compilerArgument>-Xlint:all</compilerArgument>
                    <showWarnings>true</showWarnings>
                    <showDeprecation>true</showDeprecation>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.2.1</version>
                <configuration>
                    <mainClass>org.test.int1.Main</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>
	<repositories>
		<repository>
			<id>alimaven</id>
			<name>aliyun maven</name>
			<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
			<releases>
				<enabled>true</enabled>
			</releases>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>
</project>

4、创建mybatis-config.xml配置文件，放在resource下

<?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>

</configuration>

5、创建jdbc.propertis配置文件，放在resource下

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8
jdbc.username=root
jdbc.password=root

6、创建log4j.xml配置文件，放在resource下

log4j.rootLogger=DEBUG, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

7、创建bean.xml文件，放在resource下

这里我们需要 1》开启扫描

2》加载jdbc配置文件

3》配置数据源

4》配置SqlSessionFaction(更换mybatisplus使用的SqlSessionFaction)

加载mybatis核心配置文件，配置别名包扫描，注入全局策略到SqlSessionFactory

5》sql映射文件扫描

6》定义MyBatisPlus的全局策略配置

dbColumnUnderline的值2.3版本以后，默认值为true这里如果你的数据库表的字段与实体类一样且不是t_id的形式，就为false。反之为true。另外我们再配一个全局主键。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"  
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:p="http://www.springframework.org/schema/p"  
	xmlns:context="http://www.springframework.org/schema/context"  
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
	http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
	http://www.springframework.org/schema/aop 
	http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
	http://www.springframework.org/schema/tx 
	http://www.springframework.org/schema/tx/spring-tx-4.3.xsd
	http://www.springframework.org/schema/context 
	http://www.springframework.org/schema/context/spring-context-4.3.xsd">
	
	<!-- 开启扫描 -->
	<context:component-scan base-package="cn.xxs" />
	
	<!-- 加载jdbc配置文件 -->
	<context:property-placeholder location="jdbc.properties"/>
	
	<!-- 配置数据源 -->
	<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
	        <property name="driverClassName" value="${jdbc.driverClassName}"/>
	        <property name="url" value="${jdbc.url}"/>
	        <property name="username" value="${jdbc.username}"/>
	        <property name="password" value="${jdbc.password}"/>
			<!-- 连接池的最大数据库连接数 -->
			<property name="maxActive" value="10"></property>
			<!-- 最大空闲数 -->
			<property name="minIdle" value="5"></property>
	</bean>

	<!-- 配置SqlSessionFactionBean -->
	<bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean">
		
		<property name="dataSource" ref="dataSource"></property>
		<!-- 加载mybatis核心配置文件 -->
		<property name="configLocation" value="classpath:SqlMapConfig.xml" />
		<!-- 配置别名包扫描 -->
		<property name="typeAliasesPackage" value="cn.xxs.pojo"></property>
		<!-- 注入全局策略 -->
		<property name="globalConfig" ref="globalConfiguration"></property>
	</bean>
	<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
		<!-- sql映射文件扫描 -->
		<property name="basePackage" value="cn.xxs.mapper"></property>
	</bean>
	
	<!-- 定义MyBatisPlus的全局策略配置 -->
		<bean id="globalConfiguration" class="com.baomidou.mybatisplus.entity.GlobalConfiguration">
			<!-- 2.3版本以后，默认值为true -->
			<property name="dbColumnUnderline" value="false"></property>
			
			<!-- 全局主键  -->
			<property name="idType" value="0"></property>
		</bean>
</beans>

8.编写接口，继承BaseMapper接口

这里与mybatis最大的不同就是它不需要创建sql映射文件或者是写注解

public interface UserMapper extends BaseMapper<Student>{
	
}

9.创建获取SqlSessionFactory工具类

public class SqlSessionFactoryUtil {

	private static SqlSessionFactory sqlSessionFactory;

	static {					
			sqlSessionFactory = (SqlSessionFactory) new ClassPathXmlApplicationContext("bean.xml").getBean("sqlSessionFactory");				
	}
	
	public static SqlSessionFactory getSqlSessionFactory() {
		return sqlSessionFactory;
	}	
}

10.创建测试类

/**
	 * 查询学生信息
	 * @throws IOException 
	 */
	@org.junit.Test
	public void selectById() throws IOException {
		
		//通过输入流创建SqlSessionFactory
		SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtil.getSqlSessionFactory();	
		//创建SqlSession对象
		SqlSession ss = sqlSessionFactory.openSession();		
		//多态的运用,为掉方法做准备			
		UserMapper userMapper = ss.getMapper(UserMapper.class);					
		//查询学生信息
		Student s = userMapper.selectById(4);		
			//控制台输出
		System.out.println(s);							
		//释放资源
		ss.close();	
	}

11.控制台打印结果：

mybatisPlus实现CRUD

由此可见，我们直接用方法selectById（）就可以了，很方便。

除此之外，还有很多我们可以直接用的方法，比如insert，deleteById，updateById，selectBatchIds等。

当然了我们也可以根据自己所需自己在接口编写其他方法。

mybatisPlus实现CRUD

继续阅读

Mybatis Plus 分页

Mybatis-plus快速开始核心功能

Mybatis Plus ---入门初体验Mybatis Plus —入门初体验（集成MybatisPlus）

MyBatis-Plus基础--入门程序（一）

Mybatis Plus：简介及快速入门

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mybatisPlus条件构造器AbstractWrapper

整合微服务Mybatis plus快速上手增删改查整合微服务Mybatis plus

mybatis Plus根据两个字段的和并排序

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Springboot + MyBatis Plus自动生成代码工具类，简单好用。

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