Question

尝试获取平均值，但不断收到错误消息：

操作数数据类型varchar对于avg运算符无效。

这是SQL：

select 
        COUNT(Amount)AS "TOTAL Sales Daily",
        MIN(Amount) AS "MIN Sales Daily", 
        MAX(Amount) AS "MAX Sales Daily",
        CAST(AVG(Amount)AS INTEGER) AS "AVG Salses Daily"          
from CMP_SalesDaily_Data;

Answer 1

CAST位置错误。

select 
        COUNT(Amount)AS "TOTAL Sales Daily",
        MIN(Amount) AS "MIN Sales Daily", 
        MAX(Amount) AS "MAX Sales Daily",
        AVG(CAST(Amount AS INTEGER)) AS "AVG Salses Daily"          
from CMP_SalesDaily_Data;

有效处理此问题的一种方法是，如果您无法控制AMOUNT的数据类型，可能会在以下路径中执行此操作：

select 
        COUNT(Amount)AS "TOTAL Sales Daily",
        MIN(Amount) AS "MIN Sales Daily", 
        MAX(Amount) AS "MAX Sales Daily",
        AVG(Amount) AS "AVG Salses Daily"          
from (
  select cast(amount as integer) as amount from CMP_SalesDaily_Data
);

但是，请记住验证CAST是否以某种方式对数据造成损害（例如，在需要干净处理的数据中没有“N / A”之类的内容）。

Answer 2

您的Amount字段可能属于VARCHAR类型。在将其传递给CAST之前，请先尝试CONVERT或AVG。

（假设这是SQL-Server）

Answer 3

试试这个：

AVG(cast(Amount AS INTEGER)) AS "AVG Salses Daily"

“AVG”上的SQL命令错误

3 个答案: