分组依据的 SQL QUERY 错误

Posted 2023-03-27

【中文标题】分组依据的 SQL QUERY 错误

【英文标题】：ERROR IN SQL QUERY for group by

【发布时间】：2014-09-02 17:35:00

【问题描述】：

我想按部门编号和年龄选择平均工资，我使用了这个查询

SELECT 
    DEPARTMENT_NUMBER,
    ROUND((MONTHS_BETWEEN(SYSDATE, BIRTHDAY)) / 12) AS AGE,
    AVG(SALARY)
FROM 
    EMPLOYEE 
GROUP BY 
    DEPARTMENT_NUMBER, AGE;

但我收到错误：

ORA-00904：“年龄”：标识符无效

【问题讨论】：

标记的甲骨文。 . . Oracle 错误来自 Oracle 数据库。

【参考方案1】：

您不能在 Oracle 中的 group by 中使用列别名。只需使用子查询：

SELECT DEPARTMENT_NUMBER, AGE, AVG(SALARY)
FROM (SELECT e.*, ROUND((MONTHS_BETWEEN(SYSDATE,BIRTHDAY))/12) AS AGE
      FROM EMPLOYEE
     ) e
GROUP BY DEPARTMENT_NUMBER, AGE;

【参考方案2】：

你不能按别名分组，试试这个：

    SELECT DEPARTMENT_NUMBER
           ,ROUND((MONTHS_BETWEEN(SYSDATE,BIRTHDAY))/12) AS AGE
           ,AVG(SALARY)
    FROM EMPLOYEE 
    GROUP BY DEPARTMENT_NUMBER, ROUND((MONTHS_BETWEEN(SYSDATE,BIRTHDAY))/12);