SQL 过程中的 IF 子句

Question

我用未来 15 年的所有日期创建了日期 table...

CREATE TABLE [dbo].[All_Dates](
    [Year] [int] NOT NULL,
    [Quarter] [nvarchar](6) NOT NULL,
    [Month] [nvarchar](6) NOT NULL,
    [Week] [nvarchar](7) NOT NULL,
    [Day] [nvarchar](50) NOT NULL,
    [DayKey] [tinyint] NOT NULL,
    [DateName] [nvarchar](50) NOT NULL,
    [DateKey] [date] NOT NULL,
PRIMARY KEY CLUSTERED 
(
    [DateKey] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

这样做的目的是在某些报告程序中使用该时间段。所以，现在问题就在这里，当我需要在程序开始时有一些 IF 子句时，当需要参数时，因为我需要让客户选择月度或季度报告。对于每月，我有代码：

ALTER procedure [dbo].[proc1]

@dt date

as

declare @startdate date
        ,@enddate date
SET @StartDate = (select min(datekey) from TDW.dbo.All_Dates where month = convert(varchar(6),@dt,112))
SET @EndDate = (select max(datekey) from TDW.dbo.All_Dates where month = convert(varchar(6),@dt,112))

所以，我需要类似 if time_range=quarter then...

Answer 1

假设 '201701' 等是您的 month 列的有效值，那么您应该处理开始和结束月份，然后找到它们的日期。这是一个示例：

DECLARE @dt DATE = '2017-01-01'
DECLARE @time_range VARCHAR(10) = 'quarter'

DECLARE @startmonth VARCHAR(6) = convert(VARCHAR(6), @dt, 112) -- e.g. '201701'
IF @time_range = 'quarter' SET @dt = DATEADD(m, 2, @dt) -- Assumed it is OK to change @dt
DECLARE @endmonth   VARCHAR(6) = convert(VARCHAR(6), @dt, 112) -- e.g. '201703'

DECLARE @startdate DATE, @enddate DATE
SET @StartDate = (select min(datekey) from TDW.dbo.All_Dates where month = @startmonth)
SET @EndDate   = (select max(datekey) from TDW.dbo.All_Dates where month = @endmonth)

如果需要，您可以使用多个 IF，甚至 CASE WHEN ... THEN ... ELSE ... END 语句。

SQL 过程中的 IF 子句

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sql-server

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ssrs-2008