如何将不同单元格中的相同值计为1而不是将1乘以1 sql

Question

我试图根据分行ID（B001，B002，B003）计算每个分支的监督总数。我试图得到像Sandy＆＃39; Sandy＆＃39;算作1和'Mandy＆＃39;计算为另一个（B001总共2个监督员），但在我执行后，结果显示3（Sandy分别计为2个不同的值，而不是1）。那么，我应该怎样做才能使B001分公司的主管总数变为2。

there are 3 B001 in that table, but the supervisors are only sandy and mandy which Supervisor Sandy is repeated. The result showed there are 3 supervisors after i executed, so how can i make it to 2?)

结果显示： 2

SELECT Staff.BranchID,Branch.Manager AS ManagerName, COUNT (staff.Supervisor) AS TotalNumberofSupervisor FROM Staff INNER JOIN Branch ON Branch.BranchID = Staff.BranchID GROUP BY Staff.BranchID,Branch.Manager

Answer 1

我认为＆＃34; COUNT（不同（staff.Supervisor））＆＃34;代替 ＆＃34; COUNT（staff.Supervisor）＆＃34;会有所帮助