Sql 如何在WHERE子句中使用Distinct

我有这个查询来计算员工一个月内收到的礼物数量

SELECT DISTINCT 
    COUNT([Attendance].[Status])
FROM
    [HRM].[tbl_EmployeeAttendance] [Attendance], [HRM].[tbl_EmployeeInfo] [Info]
WHERE 
    [Attendance].[Status] IN ('Early Left', 'Present', 'Half Day', 'Late In')
    AND [Info].[ID] = [Attendance].[EmpCode] 
    AND [Attendance].[EmpCode] = 266 
    AND CAST([Attendance].[AttendanceTimeIn] AS DATE) >= '2018-08-01' 
    AND CAST([Attendance].[AttendanceTimeOut] AS DATE) <= '2018-08-15'

---

现在是两次计数日期4，但它应该一次计数。

DISTINCT

应该在

count（）中。

因此，它将是：

SELECT COUNT(DISTINCT [Attendance].[Status]), 
       COUNT(DISTINCT CAST([Attendance].[AttendanceTimeIn] AS Date))
. . .

但是，我建议在

FROM

子句中使用适当的标准、明确的

JOIN

语法，而不是逗号：

SELECT COUNT(DISTINCT [Attendance].[Status]),
       COUNT(DISTINCT CAST([Attendance].[AttendanceTimeIn] AS Date))
FROM [HRM].[tbl_EmployeeAttendance] [Attendance] INNER JOIN
     [HRM].[tbl_EmployeeInfo] [Info]
     ON [Info].[ID] = [Attendance].[EmpCode] 
WHERE [Attendance].[Status] IN ('Early Left', 'Present', 'Half Day', 'Late In') AND 
      [Attendance].[EmpCode] = 266 AND 
      CAST([Attendance].[AttendanceTimeIn] AS DATE) >= '2018-08-01'AND 
      CAST([Attendance].[AttendanceTimeOut] AS DATE) <= '2018-08-15'

选择计数（不同的[出勤][状态]，
计数（不同的演员阵容（[出席人数][出席人数]截止日期））
来自[HRM].[tbl_员工考勤][考勤]内部加入
[HRM].[tbl_员工信息][信息]
在[信息].[ID]=[出席].[EmpCode]上
其中【出席】【状态】在（‘提前离开’、‘现在’、‘半天’、‘迟到’）和
[出席人数].[EmpCode]=266和
演员阵容（[出席人数][出席人数]截止日期）>='2018-08-01'和
强制转换（[Attention].[AttendanceTimeOut]作为日期）尝试此操作以强制转换到日期并执行不同的

SELECT COUNT(DISTINCT CAST([Attendance].[AttendanceTimeIn] as Date))
FROM [HRM].[tbl_EmployeeAttendance] [Attendance], [HRM].[tbl_EmployeeInfo] [Info]
WHERE [Attendance].[Status] IN ('Early Left', 'Present', 'Half Day', 'Late In')
AND [Info].[ID] = [Attendance].[EmpCode] AND [Attendance].[EmpCode] = 266 
AND CAST([Attendance].[AttendanceTimeIn] AS DATE) >= '2018-08-01' 
AND CAST([Attendance].[AttendanceTimeOut] AS DATE) <= '2018-08-15'

选择计数（不同的演员阵容（[Attention]。[AttentindaceTimein]作为日期））
来自[HRM].[tbl_EmployeeAttement][Attement]，[HRM].[tbl_EmployeeInfo][Info]
其中[出席].[状态]在（'提前离开'，'现在'，'半天'，'迟到'）
[Info].[ID]=[attention].[EmpCode]和[attention].[EmpCode]=266
和演员（[出席人数][出席人数]截止日期）>='2018-08-01'
和CAST（[Attention].[AttendanceTimeOut]AS DATE）只有一个状态，我认为他们不需要不同的状态是的，我需要不同的日期是时候开始使用ANSI-92样式的联接了。它们已经存在了25年多了。逗号分隔的表列表非常糟糕，原因有很多。
SELECT COUNT(DISTINCT CAST([Attendance].[AttendanceTimeIn] as Date))
FROM [HRM].[tbl_EmployeeAttendance] [Attendance], [HRM].[tbl_EmployeeInfo] [Info]
WHERE [Attendance].[Status] IN ('Early Left', 'Present', 'Half Day', 'Late In')
AND [Info].[ID] = [Attendance].[EmpCode] AND [Attendance].[EmpCode] = 266 
AND CAST([Attendance].[AttendanceTimeIn] AS DATE) >= '2018-08-01' 
AND CAST([Attendance].[AttendanceTimeOut] AS DATE) <= '2018-08-15'