MyBatis-Plus（MP）是 MyBatis 的增强工具，无需编写 SQL 即可完成 CRUD 操作，极大提升开发效率。本文带你实战 Spring Boot 整合 MyBatis-Plus。
引入依赖
<!-- pom.xml --> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.5.5</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> # application.yml spring: datasource: url: jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=utf8 username: root password: 123456 driver-class-name: com.mysql.cj.jdbc.Driver mybatis-plus: configuration: log-impl: org.apache.ibatis.logging.stdout.StdOutImpl global-config: db-config: logic-delete-field: deleted logic-delete-value: 1 logic-not-delete-value: 0回到顶部
二、实体类
@Data @TableName("user") public class User { @TableId(type = IdType.AUTO) private Long id; @TableField("username") private String username; private String email; private Integer age; @TableLogic // 逻辑删除 private Integer deleted; @TableField(fill = FieldFill.INSERT) private LocalDateTime createTime; @TableField(fill = FieldFill.INSERT_UPDATE) private LocalDateTime updateTime; }回到顶部
三、Mapper 接口
@Mapper public interface UserMapper extends BaseMapper<User> { // 继承 BaseMapper 后，自动拥有以下方法： // - insert(entity) // - deleteById(id) // - updateById(entity) // - selectById(id) // - selectList(wrapper) // - selectPage(page, wrapper) // 无需编写 XML！ }回到顶部
四、条件构造器
// 查询年龄大于18且邮箱不为空的用户 List<User> users = userMapper.selectList( new LambdaQueryWrapper<User>() .gt(User::getAge, 18) .isNotNull(User::getEmail) .orderByDesc(User::getCreateTime) ); // 模糊查询 List<User> users = userMapper.selectList( new LambdaQueryWrapper<User>() .likeRight(User::getUsername, "张") .between(User::getAge, 20, 30) ); // 更新：年龄大于30的用户状态改为1 userMapper.update(null, new LambdaUpdateWrapper<User>() .set(User::getStatus, 1) .gt(User::getAge, 30) );回到顶部
五、分页查询
// 分页配置类 @Configuration public class MyBatisPlusConfig { @Bean public MybatisPlusInterceptor mybatisPlusInterceptor() { MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor(); interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL)); return interceptor; } } // 分页查询 Page<User> page = new Page<>(1, 10); // 第1页，每页10条 userMapper.selectPage(page, new LambdaQueryWrapper<User>() .gt(User::getAge, 18) ); List<User> records = page.getRecords(); // 当前页数据 long total = page.getTotal(); // 总记录数 long pages = page.getPages(); // 总页数回到顶部
六、代码生成器
// AutoGenerator 一键生成 Entity、Mapper、Service、Controller AutoGenerator generator = new AutoGenerator(); // 全局配置 GlobalConfig globalConfig = new GlobalConfig(); globalConfig.setOutputDir(System.getProperty("user.dir") + "/src/main/java"); globalConfig.setAuthor("myname"); globalConfig.setOpen(false); generator.setGlobalConfig(globalConfig); // 数据源配置 DataSourceConfig dataSourceConfig = new DataSourceConfig.Builder( "jdbc:mysql://localhost:3306/mydb", "root", "123456" ).build(); generator.setDataSource(dataSourceConfig); // 策略配置 StrategyConfig strategyConfig = new StrategyConfig.Builder() .addInclude("user", "order") // 表名 .entityBuilder().enableLombok() .controllerBuilder().enableRestStyle() .build(); generator.setStrategy(strategyConfig); generator.execute();