SpringBoot+Mybatis-Plus+lombok整合，最清晰、最全面、专门提供给新手学习的好教材

 package com.mptest.test;

import java.text.ParseException;
import java.time.LocalDateTime;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.swing.plaf.synth.SynthSeparatorUI;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.additional.query.impl.LambdaQueryChainWrapper;
import com.baomidou.mybatisplus.extension.service.additional.update.impl.LambdaUpdateChainWrapper;
import com.baomidou.mybatisplus.extension.service.additional.update.impl.UpdateChainWrapper;
import com.mptest.entity.Job;
import com.mptest.mapper.JobMapper;
 


@RunWith(SpringRunner.class)
@SpringBootTest
public class JobSelectTest {
	
	@Autowired
	private JobMapper jobMapper;
	
	
	@Test
	public void getJobList() {
		//查询所有
		List list = jobMapper.selectList(null);
		//输出结果
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByMap() {
		//定义map
		Map columnMap = new HashMap();
		//设置id值
		columnMap.put("id", 1);
		//调用查询方法
		List list = this.jobMapper.selectByMap(columnMap);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapper() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//开始设置查询条件
		queryWrapper
		  .like("position", "工程")
		  .lt("id", 10);

		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}

	
	@Test
	public void getByWrapper2() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//开始设置查询条件
		queryWrapper
		  .like("position", "工")
		  .between("count", 1, 2)
		  .isNull("email");
			

		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	
	@Test
	public void getByWrapper3() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//开始设置查询条件
		queryWrapper
		  .likeRight("position", "软")
		  .or().ge("count", 3)
		  .orderByDesc("addtime")
		  .orderByAsc("id");
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapper4() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//开始设置查询条件
		queryWrapper
			.apply("date_format(addtime,'%Y-%m-%d')={0}", "2019-08-02")
			.inSql("id", "select id from dy_job where count>1");
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapper5() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//开始设置查询条件
		queryWrapper
			.like("position", "工程师")
			.and(
				sql->sql.le("count", 10).or().isNull("email")
				)
			.ge("id", 2);
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapper6() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//开始设置查询条件
		queryWrapper
			.like("position", "工程师")
			.or(
				sql->sql.le("count", 10).isNull("email")
				)
			.ge("id", 2);
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapper7() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//开始设置查询条件
		queryWrapper
			.nested(sql->sql.like("position", "java").or().ge("count", 3))
			.apply("date_format(addtime,'%Y-%m-%d')={0}", "2019-08-02")
			.last("limit 2");
			//.in("id", Arrays.asList(1,2,3,5,8));
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapper8() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//开始设置查询条件
		queryWrapper.select("id","position","addtime")
			.nested(sql->sql.like("position", "java").or().ge("count", 3))
			.apply("date_format(addtime,'%Y-%m-%d')={0}", "2019-08-02")
			.in("id", Arrays.asList(1,2,3,5,6,7,8,9,10))
			.last("limit 2");
			
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapper9() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		String positionKey = "C#";
		String countKey = null;
		//开始设置查询条件
		queryWrapper
		  .like(StringUtils.isNotEmpty(positionKey),"position", positionKey)
		  .ge(StringUtils.isNotEmpty(countKey),"count", countKey)
		  .orderByDesc("addtime")
		  .orderByAsc("id")
		  .select("id","position","addtime");
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapperEntity() {

		Job whereJob = new Job();
		whereJob.setId(11);
		whereJob.setPosition("C#架构师");
		//查询条件
		QueryWrapper queryWrapper = Wrappers.query(whereJob);
		//queryWrapper.eq("", "C#");
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapperAllEq() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		//创建map对象，并装入条件列
		Map whereMap = new HashMap();
		whereMap.put("position", "C#架构师");
		queryWrapper.allEq(whereMap);
		
		//调用查询
		List list = this.jobMapper.selectList(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapperMaps() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		queryWrapper
			.select("addtime as 招聘时间","count(*) as 职位数量")
			.gt("id", 1)
			.like("position", "师")
			.groupBy("招聘时间")
			.having("职位数量>{0} and 职位数量<{1}", 1,10);
		
		//调用查询
		List> list = this.jobMapper.selectMaps(queryWrapper);
		//打印输出
		list.forEach(System.out::println);
	}
	
	
	@Test
	public void getByWrapperObjs() {

		//查询条件
		QueryWrapper queryWrapper = Wrappers.query();
		queryWrapper
			.select("count(*) as 职位数量")
			.gt("id", 1)
			.like("position", "师")
			.groupBy("addtime")
			.having("职位数量>{0} and 职位数量<{1}", 1,10);
		
		//调用查询
		List