There are two reasons for this error
1. A certain attribute name of your entity class does not correspond to the field name of the database (either use the same name, or use ResultMap to establish a mapping relationship) 2.
If you make sure that you are all corresponding, that is: entity class No no-argument constructs! !
It is really a very inexplicable problem. After all, I made sure that I did not convert the xx type to xx type and the name of the attribute column of the database is also correct.
Because I want to pass parameters to save trouble, I customized the construction methods of some entity classes without writing no-argument structures, which would cause problems like the title when selecting, so you add
a no-argument structure to your entity class and you are done.
/**
* @ClassName Cart
* @Description TODO 购物车实体类
* @Date 2022/7/19
* @Author JayeXue
* @Version 1.0
*/
@EqualsAndHashCode(callSuper = true)
@Data
@ToString(callSuper = true)
public class Cart extends BaseEntity{
@ApiModelProperty("购物车id")
private Integer cid;
@ApiModelProperty("商品id")
private Integer pid;
@ApiModelProperty("用户id")
private Integer uid;
@ApiModelProperty("价格")
private Long price;
@ApiModelProperty("数量")
private Integer num;
public Cart() {
}
public Cart(String createdUser, Date createdTime, String changeUser, Date changeTime, Integer pid, Integer uid, Long price, Integer num) {
super(createdUser, createdTime, changeUser, changeTime);
this.pid = pid;
this.uid = uid;
this.price = price;
this.num = num;
}
}