從SQL Server表中選擇與特定月份有關的詳細數據？

Question

我在生日表中有這樣的數據

Month   Employee

Jan     John
Jan     George
April   Matt
April   Maxim

我想寫一個返回的查詢

Month    Employee

Jan      John
         George
April    Matt
         Maxim

Answer 1

    DECLARE @Birthdays TABLE ( Month NVARCHAR(15), Employee NVARCHAR(20))

    INSERT INTO @Birthdays
    ( Month,  Employee )
    SELECT
    'Jan','John'
    UNION ALL
    SELECT 'Jan','George'
    UNION ALL
    SELECT 'April','Matt'
    UNION ALL
    SELECT 'April','Maxim'

    ;WITH cte
    AS(
    SELECT Month, Employee
         ,ROW_NUMBER()OVER(PARTITION BY Month ORDER BY Month) 'RN'
    FROM @Birthdays  
    )
    SELECT
        CASE WHEN C.RN = 1 THEN C.Month ELSE '' END AS 'Month'
      , C.Employee
    FROM cte C
ORDER BY C.Month DESC

Answer 2

CREATE TABLE dbo.Birthdays (
    Month VARCHAR(100)
    ,Employee VARCHAR(100)
    );

INSERT INTO dbo.Birthdays (Month,Employee)
VALUES ('Jan','John'),( 'Jan','George'),('April','Matt'),('April','Maxim');

SELECT CASE 
        WHEN b.Month = LAG(b.Month, 1, 0) OVER (
                ORDER BY b.Month
                )
            THEN ''
        ELSE b.Month
        END AS Month
    ,b.Employee
FROM dbo.Birthdays b

Answer 3

;With cte([Month],   Employee)
AS
(
SELECT 'Jan'  ,'John'    Union all
SELECT 'Jan'  ,'George'  Union all
SELECT 'April','Matt'    Union all
SELECT 'April','Maxim'
)
SELECT CASE WHEN [MonthSeq]=1 THEN [Month] ELSE '' END AS [Month], Employee  From
(
Select * , ROW_NUMBER()Over(Partition by [Month] order by [Month] ) As [MonthSeq] from cte
)Dt
Order BY dt.[Month]  desc

產量

Month   Employee
----------------
Jan     George
        John
April   Maxim
        Matt