实际项目中，使用mybatis plus，我们经常会创建一个实体类用来和表对应，示列如下：
 

package com.arcade.earth.po;


import com.arcade.po.BaseInfo;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableName;
import com.fasterxml.jackson.annotation.JsonInclude;
import io.swagger.annotations.ApiModel;
import lombok.*;

import java.math.BigDecimal;

@EqualsAndHashCode(callSuper = true)
@TableName("tbl_site_contractor")
@ApiModel(value="SiteContractorInfo对象")
@JsonInclude(JsonInclude.Include.NON_NULL)
public class SiteContractorInfo extends BaseInfo {
    private static final long serialVersionUID = 1L;

    private String siteId;

    private String contractorId;

    private String rateType;

    private BigDecimal price;

    private String status;

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public String getSiteId() {
        return siteId;
    }

    public void setSiteId(String siteId) {
        this.siteId = siteId;
    }

    public String getContractorId() {
        return contractorId;
    }

    public void setContractorId(String contractorId) {
        this.contractorId = contractorId;
    }

    public String getRateType() {
        return rateType;
    }

    public void setRateType(String rateType) {
        this.rateType = rateType;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "SiteContractorInfo{" +
                "siteId='" + siteId + '\'' +
                ", contractorId='" + contractorId + '\'' +
                ", rateType='" + rateType + '\'' +
                ", price=" + price +
                '}';
    }
}

该实体中的属性一一对应表 tbl_site_contractor的字段，但是有时候其他查询需要用到此实体，可能额外需要添加其他属性，并不和表字段对应，比如添加projectName属性，可能会报错，具体解决办法如下

@TableField(exist = false)
private String projectName;

 在属性上添加注解@TableField(exist = false)，这样反射时就不会要求此字段必须和表字段对应了