springboot——集成mybatis-plus(通用CRUD方法)

SpringBoot集成mybatis-plus

1. maven依赖

<!-- mybaits plus 插件 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>

2.创建表

CREATE TABLE `customer` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `customer_name` varchar(255) DEFAULT NULL COMMENT '顾客名称',
  `gender` varchar(255) DEFAULT NULL COMMENT '性别',
  `telephone` varchar(255) DEFAULT NULL COMMENT '电话号码',
  `register_time` timestamp NULL DEFAULT NULL COMMENT '注册时间',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=26 DEFAULT CHARSET=utf8 COMMENT='顾客表';

3.yml配置

### mybatis-plus相关配置
mybatis-plus:
  # xml扫描，多个目录用逗号或者分号分隔（告诉 Mapper 所对应的 XML 文件位置）
  # 如果使用baseMapper就注释mapper-locations，没有文件则会报错
  #mapper-locations: classpath:/mapper/*.xml
  type-aliases-package: com.ys.dao

4.entity

这里使用了lombok：使用可参考：https://www.cnblogs.com/yu-si/articles/15079874.html

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

@Data
@TableName("customer")// @TableName映射数据库表名
public class Customer {
    //@TableId 标识这是Id 主键
    @TableId(type = IdType.AUTO)
    private Long id;
    // 如果字段和数据库列对应可省略该注解
    // @TableField(value = "NAME",exist = true)
    private String customerName;
    private String gender;
    private String telephone;
    private String registerTime;
}

5.MybatisPlusPageConfig.java

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
//@MapperScan("com.zszxz.plus.service.*.mapper*")
@MapperScan("com.ys.dao")
public class MybatisPlusPageConfig {

    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        // 设置请求的页面大于最大页后操作， true调回到首页，false 继续请求  默认false
        // paginationInterceptor.setOverflow(false);
        // 设置最大单页限制数量，默认 500 条，-1 不受限制
        // paginationInterceptor.setLimit(500);
        return paginationInterceptor;
    }
}

6.mapper.java

继承BaseMapper<>

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.ys.entity.mybatisplus.Customer;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

@Repository
@Mapper
public interface CustomerMapper extends BaseMapper<Customer> {

}

7.Test测试类

package com.ys;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.ys.dao.CustomerMapper;
import com.ys.entity.mybatisplus.Customer;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest
public class DemoApplicationTests {
    @Resource
    CustomerMapper customerMapper;

    @Test
    public void add() {
        Customer customer = new Customer();
        customer.setGender("男");
        customer.setTelephone("66566");
        int i;
        for (i = 1; i < 20; i++) {
            customer.setCustomerName("大牛"+i);
            customerMapper.insert(customer);
        }
        System.out.println("============执行"+i+"条============");
    }

    @Test
    public void update() {
        Customer customer = new Customer();
        customer.setId(0L);
        customer.setCustomerName("二牛");
        customer.setGender("男");
        customer.setTelephone("66566");
        customerMapper.updateById(customer);
    }

    @Test
    public void delete() {
//        customerMapper.deleteById(24L);//根据id删除
        // 条件封装
        QueryWrapper<Customer> wrapper = new QueryWrapper<Customer>();
        wrapper.ge(true,"id",0L);
        int delete = customerMapper.delete(wrapper);
        System.out.println("============执行"+delete+"条============");

    }

    @Test
    public void selectById() {
        Customer customer = customerMapper.selectById(26L);
        // Customer(id=26, customerName=大牛哥, gender=男, telephone=66566, registerTime=null)
        System.out.println(customer);
    }

    @Test
    public void selectByWrapper() {
        // 条件封装
        QueryWrapper<Customer> wrapper = new QueryWrapper<Customer>();
        wrapper.eq("id",26L);
        List<Customer> customers = customerMapper.selectList(wrapper);
        // [Customer(id=26, customerName=大牛哥, gender=男, telephone=66566, registerTime=null)]
        System.out.println(customers);
    }

    @Test
    public void page() {
        Page<Customer> page = new Page<>(1, 10);
        IPage<Customer> customerIPage = customerMapper.selectPage(page, null);
        List<Customer> records = customerIPage.getRecords();
        for (Customer record : records) {
            System.out.println("========="+record.toString());
        }
    }

}