SQL：使用SUM和COUNT函数的结果异常

Question

考虑到“无限制的前导和当前行之间的范围”的概念，我使用了代码中所见的SUM和COUNT函数，如果您查看我的结果，在TotalSalary下，我希望第一行为1000，第二行似乎是正确的，即1000 + 1000 = 2000，第三行又是不正确的，即1000 + 1000 + 2000应该是4000，但它是6000，这是您的想法，类似地，计数似乎也给出了错误的结果，我希望， 1,2,3,4,5,6 ..

DECLARE @Employees TABLE
(   EmpId INT Identity(1,1) NOT NULL, 
    EmpName VARCHAR(50) NULL,
    EmpGender VARCHAR(10),
    EmpSalary INT
);

INSERT INTO @Employees VALUES ('Rehan','Male', 2000 );
INSERT INTO @Employees VALUES ('Rohan','Male', 3000 );
INSERT INTO @Employees VALUES ('Donna','Female', 2500 );
INSERT INTO @Employees VALUES ('Mark','Male', 1000);
INSERT INTO @Employees VALUES ('Aarav','Female', 1000);
INSERT INTO @Employees VALUES ('Nick','Male', 2000);

SELECT 
    EmpId, EmpName, EmpGender, EmpSalary
    , SUM(EmpSalary) OVER (ORDER BY EmpSalary) 'TotalSalary'
    , COUNT(EmpSalary) OVER (ORDER BY EmpSalary) 'Count'
FROM @Employees;

Answer 1

您需要添加ROWS UNBOUNDED PRECEDING，默认值为RANGE。

所以

SELECT 
    EmpId, EmpName, EmpGender, EmpSalary
    , SUM(EmpSalary) OVER (ORDER BY EmpSalary ROWS UNBOUNDED PRECEDING) 'TotalSalary'
    , COUNT(EmpSalary) OVER (ORDER BY EmpSalary ROWS UNBOUNDED PRECEDING) 'Count'
FROM @Employees;

返回类似

+-------+---------+-----------+-----------+-------------+-------+
| EmpId | EmpName | EmpGender | EmpSalary | TotalSalary | Count |
+-------+---------+-----------+-----------+-------------+-------+
|     4 | Mark    | Male      |      1000 |        1000 |     1 |
|     5 | Aarav   | Female    |      1000 |        2000 |     2 |
|     6 | Nick    | Male      |      2000 |        4000 |     3 |
|     1 | Rehan   | Male      |      2000 |        6000 |     4 |
|     3 | Donna   | Female    |      2500 |        8500 |     5 |
|     2 | Rohan   | Male      |      3000 |       11500 |     6 |
+-------+---------+-----------+-----------+-------------+-------+

在绑定EmpSalary的情况下，哪一行排在第一位是任意的

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