5.mybatisPlus

1.pom

 <dependencies>
<!--        springboot-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
<!--        mybatis-plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.1.2</version>
        </dependency>
<!--        lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <!--Mysql数据库驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.15</version>
        </dependency>
    </dependencies>

2.实体

@Data
public class User {
    
    
    private Long id;
    private String name;
    private Integer age;
    private String email;
}

3.mapper

public interface UserMapper extends BaseMapper<User> {
    
    
}

4.启动类

@SpringBootApplication
@MapperScan("com.example.demo.mapper")
public class DemoApplication {
    
    
    public static void main(String[] args) {
    
    
        SpringApplication.run(DemoApplication.class, args);
    }
}

使用细节：

userMapper.selectBatchIds(Arrays.asList(1,2,3));
Map map = new HashMap<String,Object>();
map.put("name","Tom");
map.put("age",28);
userMapper.selectByMap(map);
SELECT id,name,age,email FROM user WHERE name = ? AND age = ? 
QueryWrapper 里的方法可以写复杂的sql  具体参看mybatis-plus 条件构造器
QueryWrapper<User> wrapper = new QueryWrapper();
wrapper.eq("name","Tom").eq("age",28);
userMapper.selectOne(wrapper);

dev 表示开发环境

自动生成代码

package com.example.demo;
import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.GlobalConfig;
import com.baomidou.mybatisplus.generator.config.PackageConfig;
import com.baomidou.mybatisplus.generator.config.StrategyConfig;
import com.baomidou.mybatisplus.generator.config.po.TableFill;
import com.baomidou.mybatisplus.generator.config.rules.DateType;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;

import java.util.ArrayList;

public class kuangCode {
    
    
        public static void main(String[] args) {
    
    
// 需要构建一个 代码自动生成器 对象
            AutoGenerator mpg = new AutoGenerator();
// 配置策略
// 1、全局配置
            GlobalConfig gc = new GlobalConfig();
            String projectPath = System.getProperty("user.dir");
            gc.setOutputDir(projectPath + "/src/main/java");
            gc.setAuthor("zyf");
            gc.setOpen(false);
            gc.setFileOverride(false); // 是否覆盖
            gc.setServiceName("%sService"); // 去Service的I前缀
            gc.setIdType(IdType.ID_WORKER);
            gc.setDateType(DateType.ONLY_DATE);
            gc.setSwagger2(true);
            mpg.setGlobalConfig(gc);
//2、设置数据源
            DataSourceConfig dsc = new DataSourceConfig();
            dsc.setUrl("jdbc:mysql://localhost:3306/mall?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai");
            dsc.setDriverName("com.mysql.cj.jdbc.Driver");
            dsc.setUsername("root");
            dsc.setPassword("1234");
            dsc.setDbType(DbType.MYSQL);
            mpg.setDataSource(dsc);
//3、包的配置
            PackageConfig pc = new PackageConfig();
            pc.setModuleName("blog");
            pc.setParent("com.zyf");
            pc.setEntity("entity");
            pc.setMapper("mapper");
            pc.setService("service");
            pc.setController("controller");
            mpg.setPackageInfo(pc);
//4、策略配置
            StrategyConfig strategy = new StrategyConfig();
            strategy.setInclude("user"); // 设置要映射的表名
            strategy.setNaming(NamingStrategy.underline_to_camel);
            strategy.setColumnNaming(NamingStrategy.underline_to_camel);
            strategy.setEntityLombokModel(true); // 自动lombok；
            strategy.setLogicDeleteFieldName("deleted");
// 自动填充配置
            TableFill gmtCreate = new TableFill("gmt_create", FieldFill.INSERT);
            TableFill gmtModified = new TableFill("gmt_modified", FieldFill.INSERT_UPDATE);
            ArrayList<TableFill> tableFills = new ArrayList<>();
            tableFills.add(gmtCreate);
            tableFills.add(gmtModified);
            strategy.setTableFillList(tableFills);
// 乐观锁
//        strategy.setVersionFieldName("version");
//        strategy.setRestControllerStyle(true);
//        strategy.setControllerMappingHyphenStyle(true); //
//        localhost:
//        8080 / hello_id_2
            mpg.setStrategy(strategy);
            mpg.execute(); //执行
        }
}
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-generator</artifactId>
    <version>3.0.7.1</version>
</dependency>
<dependency>
    <groupId>org.apache.velocity</groupId>
    <artifactId>velocity-engine-core</artifactId>
    <version>2.2</version>
</dependency>