Failed to convert property value of type ‘null‘ to required type ‘double‘ for property ‘balance‘解决方案

网上方法

源代码：

    private int id;
    private String name;
    private double balance;

只需要把int和double换成整数和小数的包装类Integer和Double就可以了

    private Integer id;
    private String name;
    private Double balance;

最后重新生成get和set方法，重新运行

 

我用了 IFNULL(max(chg),0) as chg