Question

我试图在我的数据库（sql server）中分配一年中明智的叶子，但它在我的尝试代码下面失败了

select count(*)(SELECT DATEPART(yyyy,Date) AS OrderYear,
DATEPART(mm,Date) AS OrderMonth,
DATEPART(dd,Date) AS OrderDay
FROM Leaves
WHERE EmployeeID=37) FROM Leaves where OrderYear = '2016'

Answer 1

以下代码将执行您需要执行的操作。只需对上面的代码做一些小改动：

您将需要一个内部查询，它将提取日期部分，然后需要选择它们。
外部查询需要从内部查询中选择并过滤新的日期部分字段。

我将如何做到这一点：

select 
    count(*)
FROM
(
    SELECT 
        DATEPART(yyyy, Date) AS OrderYear,
        DATEPART(mm, Date) AS OrderMonth,
        DATEPART(dd, Date) AS OrderDay
    FROM 
        Leaves
    WHERE 
        EmployeeID = 37
) A
WHERE 
    OrderYear = '2016';

Answer 2

您可以寻找：

;WITH CTE AS(

 SELECT 1 as MonthNumber 
 UNION ALL
 SELECT MonthNumber+1 AS MonthNumber
 FROM CTE
 WHERE MonthNumber<=12
)
SELECT MonthNumber,COUNT(*) 
FROM CTE
LEFT JOIN Leaves ON MONTH(DATE) = MonthNumber AND EmployeeID=37 AND YEAR(Date)=2016 
GROUP BY MonthNumber

我试图将一年中明智的叶子分配给我的数据库（sql server），但它失败了。下面是我试过的代码

2 个答案: