Question

我正在尝试创建存储过程，该存储过程将返回行WHERE在“开始”和“结束”值之间的创建日期。但是我想考虑存储过程为空值的可能性，因此我需要默认值。

CREATE PROCEDURE [dbo].[GetProjectsRatingByCreationDateInterval]
    @Start DATETIME = GETDATE,
    @End DATETIME = DATEADD(MONTH, -1, GETDATE())
AS
    SELECT 
        ID, ProjectName, Rating, CreationDateTime 
    FROM 
        Projects 
    WHERE 
        CreationDateTime BETWEEN @Start AND @End

试图这样做，但收到此错误：

'（'附近的语法不正确。

它引用DATEADD声明中的@End函数调用。

Answer 1

请将该值设置为Null并在内部程序中进行如下设置

CREATE PROCEDURE [dbo].[GetProjectsRatingByCreationDateInterval]

    @Start DATETIME  NULL,
    @End DATETIME NULL
AS

IF @Start is null   
    SET @Start = GETDATE()

IF @End is null     
SET @End = DATEADD(MONTH, -1, GETDATE())

    SELECT 
        ID, ProjectName, Rating, CreationDateTime 
    FROM 
        Projects 
    WHERE 
        CreationDateTime BETWEEN @Start and @End

Answer 2

问题在这里

@Start DATETIME = GETDATE,

getdate是一个函数，因此将其写为GETDATE（）

@Start DATETIME = GETDATE(),

过程看起来像这样

    CREATE PROCEDURE [dbo].[GetProjectsRatingByCreationDateInterval]
        @Start DATETIME = GETDATE(),
        @End DATETIME = DATEADD(MONTH, -1, GETDATE())
    AS
    BEGIN
        SELECT 
            ID, ProjectName, Rating, CreationDateTime 
        FROM 
            Projects 
        WHERE 
            CreationDateTime BETWEEN @Start AND @End
     END

Answer 3

您可以根据需要使用以下代码。

CREATE PROCEDURE [dbo].[GetProjectsRatingByCreationDateInterval]
    @Start DATETIME = CURRENT_TIMESTAMP,
    @End DATETIME = NULL
AS
    SELECT 
        ID, ProjectName, Rating, CreationDateTime 
    FROM 
        Projects 
    WHERE 
        CreationDateTime BETWEEN @Start AND (CASE WHEN @End IS NULL THEN DATEADD(MONTH, -1, @Start) ELSE @End END)

Answer 4

如果传递的是ISNULL()，您还可以使用NULL函数将其默认设置为一个值：

CREATE PROCEDURE dbo.GetProjectsRatingByCreationDateInterval
    @Start DATETIME NULL, @End DATETIME NULL
AS
BEGIN
    SET @Start = ISNULL(@Start, GETDATE());
    SET @End = ISNULL(@Start, DATEADD(MONTH, -1, GETDATE()));

    SELECT ID, ProjectName, Rating, CreationDateTime
    FROM Projects
    WHERE CreationDateTime BETWEEN @Start AND @End;
END;

计算存储过程的默认日期时间参数

4 个答案: