SQLPlus - 跨多个表的Count函数

Question

我正在尝试计算数据中的骑手数量。我很难搞清楚这一点。我的输出样本如下所示。数据来自许多不同的表格，我不得不加入表格，这不是我遇到的问题。我试图通过DESCRIPTION来获取EVENT的计数数量。并仍然显示如下所示的列。

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

我尝试过一堆不同的代码，但这是我尝试过的一个示例。我迷失了，所以任何帮助都会很大！

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

Answer 1

您正在寻找类似的东西：

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