sql AVERAGE函数

Question

我正在尝试让我的输出显示比总平均次数多的旅行的客户。总体平均值为2.5。任何有关正确方向的帮助/提示都会非常感激。

 SELECT 
       customer.cus_fname "Customer First Name",
       customer.cus_lname "Customer Last Name",
        AVG(count(charter.char_trip)) > 3 "Number of Flights"     
 FROM chartname.customer 
 LEFT JOIN chartname.charter ON customer.cus_code= charter.cus_code
 GROUP BY customer.cus_fname, customer.cus_lname;

Answer 1

您正在寻找having子句：

 SELECT cu.cus_fname "Customer First Name", cu.cus_lname "Customer Last Name",
        count(ch.char_trip) "Number of Flights"     
 FROM chartname.customer cu LEFT JOIN
      chartname.charter ch
      ON cu.cus_code =  ch.cus_code
 GROUP BY cu.cus_fname, cu.cus_lname
 HAVING COUNT(ch.char_trip) >= 3;

过滤条件包含where或having条款，而不是select条款。