@Test
    public void testMap(){
        Map map = new HashMap();
        map.put("cname","测试");
        map.put("password","123456");
        List list = customerMapper.selectByMap(map);
        list.forEach(System.out::println);
    }

  @Test
    public void findCondition2() {
        Customer customer = new Customer();
        customer.setPassword("777");
        customer.setCname("888");
        customer.setIdList(Arrays.asList(2,3,4));
        customer.setCid(3);
        //条件查询
        QueryWrapper<Customer> queryWrapper = new QueryWrapper<>();
        // 1) 等值查询
        queryWrapper.eq( customer.getPassword()!=null ,"password", customer.getPassword());
        // 2) 模糊查询
        queryWrapper.like(customer.getCname() != null , "cname",customer.getCname());
        // 3) in语句
        queryWrapper.in(customer.getIdList() != null , "cid",customer.getIdList());
        // 4) 大于等于
        queryWrapper.ge(customer.getCid() != null , "cid" , customer.getCid());
        //查询
        List<Customer> list = customerMapper.selectList(queryWrapper);
        //list.forEach(customer-> System.out.println(customer));
        list.forEach(System.out::println);
    }

@Test
    public void testWrapperUpdate(){
        //1 更新数据
        Customer customer = new Customer();
        customer.setVersion(1);
        //2 更新条件
        UpdateWrapper<Customer> updateWrapper = new UpdateWrapper<>();
        updateWrapper.in("cid", 1,2,3);
        //3 更新
        int update = customerMapper.update(customer, updateWrapper);
        System.out.println(update);
    }

package com.czxy.mp.config;
import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.autoconfigure.ConfigurationCustomizer;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MybatisPlusConfig {
    /**
     * 配置插件
     * @return
     */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
        // 分页插件
        mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return mybatisPlusInterceptor;
    }
    /**
     * 新的分页插件,一缓和二缓遵循mybatis的规则,需要设置 MybatisConfiguration#useDeprecatedExecutor = false 避免缓存出现问题(该属性会在旧插件移除后一同移除)
     * @return
     */
    @Bean
    public ConfigurationCustomizer configurationCustomizer() {
        return configuration -> configuration.setUseDeprecatedExecutor(false);
    }
}

@Test
    public void testPage(){
        // 分页数据
        int pageNum = 1;
        int pageSize = 3;
        Page<Customer> page = new Page<>(pageNum , pageSize);
        page.setSearchCount(true);
        // 查询
        customerMapper.selectPage(page, null);
        // 分页数据
        System.err.println("当前页码：" + page.getCurrent());
        System.err.println("每页显示记录数：" + page.getSize());
        System.err.println("总页数：" + page.getPages());
        System.err.println("总记录数：" + page.getTotal());
        System.err.println("是否有下一页：" + page.hasNext());
        System.err.println("是否有上一页：" + page.hasPrevious());
        // 分页数据列表
        page.getRecords().forEach(System.err::println);
    }

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl  #输出日志
    map-underscore-to-camel-case: true  #驼峰命名
  global-config:
    db-config:
      id-type: auto  #全局配置，id自动增强
      table-prefix: tmp_ #表名前缀
  type-aliases-package: com.czxy.mp.domain #别名包扫描路径
  mapper-locations: classpath*:/mapper/**/*.xml #映射文件位置

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.czxy.mp.mapper.CustomerMapper">
    <select id="findAll" resultType="customer">
        select * from tmp_customer
    </select>
</mapper>

package com.czxy.mp.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.czxy.mp.domain.Customer;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;
@Mapper
public interface CustomerMapper extends BaseMapper<Customer> {
    public List<Customer> findAll();
}