💕【必看】Mybatis-Plus中的SelectById(id)的实现逻辑

了解一下实现规则会避免很多的坑 🙌

//实体字段代码
@Data
@TableName("user_buyer")
public class ShoppingBuyer {
    private Long id;
    @TableField(exist = false)
    private Long cityId;
    private String openid;
    private Integer type;
    private String phone;
    private Integer isUser;
}
//Java代码
ShoppingBuyer shoppingBuyer = shoppingBuyerMapper.selectById(buyerId);
//Java代码按照MyBatis-Plus的规则会生成一条SQL
select id,city_id,opneid,type,phone isUser from user_buyer where id = #{id}

• 规则如下：

一个实体的字段如果没有被【@TableField(exist = false)】注解修饰那么他就会作为SQL查询的字段，所以我们要确保实体中未被【@TableField(exist = false)】修饰的字段一定要在MySQL的表结构中包含此字段。🤯