六、插件
1、分页插件
MyBatis Plus自带分页插件，只要简单的配置即可实现分页功能
a>添加配置类
@MapperScan("com.jerry.mybatisplus.mapper") @Configuration public class MybatisPlusConfig { @Bean public MybatisPlusInterceptor mybatisPlusInterceptor(){ MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor(); interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL)); return interceptor; } }
b>测试
@Test public void testPage(){ //设置分页参数 Page<User> page = new Page<>(1, 5); userMapper.selectPage(page, null); //获取分页数据 List<User> records = page.getRecords(); records.forEach(System.out::println); System.out.println("当前页："+page.getCurrent()); System.out.println("每页显示的条数："+page.getSize()); System.out.println("总记录数："+page.getTotal()); System.out.println("总页数："+page.getPages()); System.out.println("是否有上一页："+page.hasPrevious()); System.out.println("是否有下一页："+page.hasNext()); }
八、代码生成器
1、引入依赖
<dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-generator</artifactId> <version>3.5.1</version> </dependency> <dependency> <groupId>org.freemarker</groupId> <artifactId>freemarker</artifactId> <version>2.3.31</version> </dependency>
2、快速生成
package com.jerry.mybatisplus; import com.baomidou.mybatisplus.generator.FastAutoGenerator; import com.baomidou.mybatisplus.generator.config.OutputFile; import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine; import java.util.Collections; /** * ClassName: FastAutoGeneratorTest * Package: com.jerry.mybatisplus * Description: * * @Author jerry_jy * @Create 2023-02-10 16:39 * @Version 1.0 */ public class FastAutoGeneratorTest { public static void main(String[] args) { FastAutoGenerator.create("jdbc:mysql://127.0.0.1:3306/mybatis_plus?characterEncoding=utf-8&userSSL=false", "root", "root") .globalConfig(builder -> { builder.author("jerry") // 设置作者 //.enableSwagger() // 开启 swagger 模式 .fileOverride() // 覆盖已生成文件 .outputDir("D://mybatis_plus"); // 指定输出目录 }) .packageConfig(builder -> { builder.parent("com.jerry") // 设置父包名 .moduleName("mybatisplus") // 设置父包模块名 .pathInfo(Collections.singletonMap(OutputFile.mapperXml, "D://mybatis_plus"));// 设置mapperXml生成路径 }) .strategyConfig(builder -> { builder.addInclude("user") // 设置需要生成的表名 .addTablePrefix("t_", "c_"); // 设置过滤表前缀 }) .templateEngine(new FreemarkerTemplateEngine()) // 使用Freemarker引擎模板，默认的是Velocity引擎模板 .execute(); } }
十、MyBatisX插件
MyBatis-Plus为我们提供了强大的mapper和service模板，能够大大的提高开发效率 但是在真正开发过程中，MyBatis-Plus并不能为我们解决所有问题，例如一些复杂的SQL，多表 联查，我们就需要自己去编写代码和SQL语句，
我们该如何快速的解决这个问题呢，这个时候可 以使用MyBatisX插件 MyBatisX一款基于 IDEA 的快速开发插件，为效率而生。
1、新建spring boot工程
a>引入依赖
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <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 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.7.1</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.jerry</groupId> <artifactId>mybatisplus</artifactId> <version>0.0.1-SNAPSHOT</version> <name>mybatisplus</name> <description>mybatisplus</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.5.1</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
b>配置application.yml
spring: # 配置数据源信息 datasource: # 配置数据源类型 type: com.zaxxer.hikari.HikariDataSource # 配置连接数据库的各个信息 driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://localhost:3306/mybatis_plus?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false username: root password: root
c>连接MySQL数据库
(E:/typora/image-20230210173113435.png)]
填好【用户名】、【密码】、【数据库名字】
d>MybatisX逆向生成
填好【模块路径】、【包名】、【实体类名】
2、MyBatisX快速生成CRUD
package com.jerry.mybatisplusx.mapper; import java.util.List; import org.apache.ibatis.annotations.Param; import com.jerry.mybatisplusx.pojo.User; import com.baomidou.mybatisplus.core.mapper.BaseMapper; /** * @author Admin * @description 针对表【user】的数据库操作Mapper * @createDate 2023-02-10 17:32:51 * @Entity com.jerry.mybatisplusx.pojo.User */ public interface UserMapper extends BaseMapper<User> { int insertSelective(User user);//增 int deleteByIdAndName(@Param("id") Long id, @Param("name") String name);//删 int updateAgeAndSexById(@Param("age") Integer age, @Param("sex") Integer sex, @Param("id") Long id);//改 List<User> selectAgeAndSexByAgeBetween(@Param("beginAge") Integer beginAge, @Param("endAge") Integer endAge);//查 List<User> selectAllOrderByAgeDesc();//排序 }
