SQLPlus - 跨多个表的计数函数

Question

我正在尝试计算我的数据中的骑手人数。我很难弄清楚这一点。我的输出示例如下所示。数据来自许多不同的表，我必须加入这些表，这不是我遇到的问题。我正在尝试通过 EVENT by DESCRIPTION 获取 RIDERS 的计数。并且仍然显示如下所述的列。

SQL> SELECT EVENTNAME, DESCRIPTION, RIDERS2  FROM ERP_REPORT;

EVENTNAME              DESCRIPTION                              RIDERS
------------------------------ ------------------------------ 
Ace Rental Car - Fair Hill Inv Day 1 Race on Fair Hill's Easy   Aaron Adams
itational                       level Course

Ace Rental Car - Fair Hill Inv Day 1 Race on Fair Hill's Easy   Aaron Adams
itational                       level Course

Ace Rental Car - Fair Hill Inv Day 2 Race on Fair Hill's Inte   Aaron Adams
itational                      rmediate level Course

Huffy's Mountain Trip          Weekend 1 Race 1 on Huffy Moun   Sam Adams
                           tain's Easy level Course

Valley Spring Water Mountain B Day 3 Race on Hoola Hut Gorge'   Jay Gillgan
ike Extravaganza               s Intermediate level Course

我尝试了一堆不同的代码，但这是我尝试过的一个示例。我对此感到迷茫，所以任何帮助都会很大！

SELECT COUNT(DISTINCT RIDERS) as "RIDERS"
2  FROM ERP_REPORT;

Answer 1

您是否正在寻找类似的东西：

SELECT COUNT(riders) AS rider_count, eventname, description
  FROM erp_report
  GROUP BY eventname, description;