为什么此查询显示错误 ORA-00923: FROM keyword not found where expected?

【问题标题】：Why is this query showing error ORA-00923: FROM keyword not found where expected?为什么此查询显示错误 ORA-00923: FROM keyword not found where expected?
【发布时间】：2023-03-03 00:45:01
【问题描述】：

我有一个 sql 查询，执行时会抛出错误：

ORA-00923: FROM keyword not found where expected

下面是 SQL：

SELECT A.Agent_key, Sum(Total_Orders) 

FROM

(SELECT A.Agent_key, Sum(Total_Orders)

     RANK() OVER (ORDER BY Sum(Total_Orders) ASC) AS Rank

     FROM Fact_Order F, Dim_Time T

     WHERE F.Time_Id = T.Time_Id AND T.Quarter= '1' AND

     TO_CHAR(SYSDATE, 'YYYY') = T.Year

     GROUP BY A.Agent_key

)

WHERE Rank < = 1;

【问题讨论】：

标签： oracle subquery oracle-apex oracle12c

【解决方案1】：

Sum(Total_Orders) 后面少了一个逗号
您还缺少子查询的别名（您在外部选择子句中使用A.Agent_key，那么A 必须是子查询的别名）
外部查询中的group by 子句丢失。（您正在使用聚合，因此需要 GROUP BY）
sum(total_agents) 的别名，正如您在外部查询中所指的那样

应该是

SELECT A.Agent_key, Sum(Total_Orders) 
FROM
(SELECT A.Agent_key, Sum(Total_Orders) as total_orders,
        RANK() OVER (ORDER BY Sum(Total_Orders) ASC) AS Rnk
   FROM Fact_Order F, Dim_Time T
  WHERE F.Time_Id = T.Time_Id
    AND T.Quarter= '1' 
    AND TO_CHAR(SYSDATE, 'YYYY') = T.Year
 GROUP BY A.Agent_key ) A
WHERE Rnk < = 1
GROUP BY A.Agent_key;

【讨论】：