Sql CTE查询失败，出现关于未知列名的错误

我正在学习CTE，我在做一个练习。请看下表：

捐赠

计划

支持者

目的是显示支持者的名字和姓氏，以及尚未成立的项目数量和金额<他们创建的最小金额

我的SQL：

WITH projects AS
( 
    SELECT 
        first_name AS firstName,
        last_name AS lastName,
        project_id,
        SUM(amount) AS amountSum,
        minimal_amount
    FROM 
        donation d
    INNER JOIN 
        project p ON p.id = d.project_id
    INNER JOIN 
        supporter s ON s.id = p.author_id
    GROUP BY 
        FIRST, LAST, project_id
)
SELECT 
    firstName,
    lastName,
    COUNT(project_id)
FROM 
    projects
WHERE 
    amountSum < minimal_amount;

我有一个错误：

第一列不存在

---

您在GROUP BY FIRST、LAST中提到列名是错误的，这在您的表中不存在，并且最小金额也需要包含在GROUP BY子句中，因为您没有对该列使用任何聚合

    WITH projects AS
      ( 
       SELECT first_name AS firstName,
               last_name AS lastName,
               project_id,
               sum(amount) AS amountSum,
               minimal_amount
       FROM donation d
       INNER JOIN project p ON p.id = d.project_id
       INNER JOIN supporter s ON s.id = p.author_id
       GROUP BY first_name ,
                last_name ,
                project_id,minimal_amount
)
    SELECT firstName,
           lastName,
           count(project_id)
    FROM projects
    WHERE amountSum < minimal_amount
   group by firstName,
           lastName

---

你的dbms是什么？你的groupby应该是名字和姓氏吗？应该是通用的，但我使用Postres@这是我的主意。在练习的描述中没有这样的要求。为什么我的问题被否决了？我得到了错误：column projects.firstname必须出现在GROUP BY子句中或用于聚合函数中。@menteith yap编辑的答案需要在GROUP BY子句中找到

+----+------------+-----------+
| id | first_name | last_name |
+----+------------+-----------+
| 1  | Marlene    | Wagner    |
| 2  | Lonnie     | Goodwin   |
| 3  | Sophie     | Peters    |
| 4  | Edwin      | Paul      |
| 5  | Hugh       | Thornton  |
| 6  | Dianne     | Harris    |
+----+------------+-----------+

WITH projects AS
( 
    SELECT 
        first_name AS firstName,
        last_name AS lastName,
        project_id,
        SUM(amount) AS amountSum,
        minimal_amount
    FROM 
        donation d
    INNER JOIN 
        project p ON p.id = d.project_id
    INNER JOIN 
        supporter s ON s.id = p.author_id
    GROUP BY 
        FIRST, LAST, project_id
)
SELECT 
    firstName,
    lastName,
    COUNT(project_id)
FROM 
    projects
WHERE 
    amountSum < minimal_amount;

    WITH projects AS
      ( 
       SELECT first_name AS firstName,
               last_name AS lastName,
               project_id,
               sum(amount) AS amountSum,
               minimal_amount
       FROM donation d
       INNER JOIN project p ON p.id = d.project_id
       INNER JOIN supporter s ON s.id = p.author_id
       GROUP BY first_name ,
                last_name ,
                project_id,minimal_amount
)
    SELECT firstName,
           lastName,
           count(project_id)
    FROM projects
    WHERE amountSum < minimal_amount
   group by firstName,
           lastName