Answers:
您可以在SQL Server中创建日期维度或日历表并对其进行查询
--demo setup
drop table if exists #dim
DECLARE @StartDate DATE = '20000101', @NumberOfYears INT = 30;
-- prevent set or regional settings from interfering with
-- interpretation of dates / literals
SET DATEFIRST 7;
SET DATEFORMAT mdy;
SET LANGUAGE US_ENGLISH;
DECLARE @CutoffDate DATE = DATEADD(YEAR, @NumberOfYears, @StartDate);
-- this is just a holding table for intermediate calculations:
CREATE TABLE #dim
(
[date] DATE PRIMARY KEY,
[day] AS DATEPART(DAY, [date]),
[month] AS DATEPART(MONTH, [date]),
FirstOfMonth AS CONVERT(DATE, DATEADD(MONTH, DATEDIFF(MONTH, 0, [date]), 0)),
[MonthName] AS DATENAME(MONTH, [date]),
[week] AS DATEPART(WEEK, [date]),
[ISOweek] AS DATEPART(ISO_WEEK, [date]),
[DayOfWeek] AS DATEPART(WEEKDAY, [date]),
[quarter] AS DATEPART(QUARTER, [date]),
[year] AS DATEPART(YEAR, [date]),
FirstOfYear AS CONVERT(DATE, DATEADD(YEAR, DATEDIFF(YEAR, 0, [date]), 0)),
Style112 AS CONVERT(CHAR(8), [date], 112),
Style101 AS CONVERT(CHAR(10), [date], 101)
);
-- use the catalog views to generate as many rows as we need
INSERT #dim([date])
SELECT d
FROM
(
SELECT d = DATEADD(DAY, rn - 1, @StartDate)
FROM
(
SELECT TOP (DATEDIFF(DAY, @StartDate, @CutoffDate))
rn = ROW_NUMBER() OVER (ORDER BY s1.[object_id])
FROM sys.all_objects AS s1
CROSS JOIN sys.all_objects AS s2
-- on my system this would support > 5 million days
ORDER BY s1.[object_id]
) AS x
) AS y;
drop table if exists dbo.DateDimension
CREATE TABLE dbo.DateDimension
(
--DateKey INT NOT NULL PRIMARY KEY,
[Date] DATE NOT NULL,
[Day] TINYINT NOT NULL,
DaySuffix CHAR(2) NOT NULL,
[Weekday] TINYINT NOT NULL,
WeekDayName VARCHAR(10) NOT NULL,
IsWeekend BIT NOT NULL,
IsHoliday BIT NOT NULL,
HolidayText VARCHAR(64) SPARSE,
DOWInMonth TINYINT NOT NULL,
[DayOfYear] SMALLINT NOT NULL,
WeekOfMonth TINYINT NOT NULL,
WeekOfYear TINYINT NOT NULL,
ISOWeekOfYear TINYINT NOT NULL,
[Month] TINYINT NOT NULL,
[MonthName] VARCHAR(10) NOT NULL,
[Quarter] TINYINT NOT NULL,
QuarterName VARCHAR(6) NOT NULL,
[Year] INT NOT NULL,
MMYYYY CHAR(6) NOT NULL,
MonthYear CHAR(7) NOT NULL,
FirstDayOfMonth DATE NOT NULL,
LastDayOfMonth DATE NOT NULL,
FirstDayOfQuarter DATE NOT NULL,
LastDayOfQuarter DATE NOT NULL,
FirstDayOfYear DATE NOT NULL,
LastDayOfYear DATE NOT NULL,
FirstDayOfNextMonth DATE NOT NULL,
FirstDayOfNextYear DATE NOT NULL
);
INSERT dbo.DateDimension WITH (TABLOCKX)
SELECT
--DateKey = CONVERT(INT, Style112),
[Date] = [date],
[Day] = CONVERT(TINYINT, [day]),
DaySuffix = CONVERT(CHAR(2), CASE WHEN [day] / 10 = 1 THEN 'th' ELSE
CASE RIGHT([day], 1) WHEN '1' THEN 'st' WHEN '2' THEN 'nd'
WHEN '3' THEN 'rd' ELSE 'th' END END),
[Weekday] = CONVERT(TINYINT, [DayOfWeek]),
[WeekDayName] = CONVERT(VARCHAR(10), DATENAME(WEEKDAY, [date])),
[IsWeekend] = CONVERT(BIT, CASE WHEN [DayOfWeek] IN (1,7) THEN 1 ELSE 0 END),
[IsHoliday] = CONVERT(BIT, 0),
HolidayText = CONVERT(VARCHAR(64), NULL),
[DOWInMonth] = CONVERT(TINYINT, ROW_NUMBER() OVER
(PARTITION BY FirstOfMonth, [DayOfWeek] ORDER BY [date])),
[DayOfYear] = CONVERT(SMALLINT, DATEPART(DAYOFYEAR, [date])),
WeekOfMonth = CONVERT(TINYINT, DENSE_RANK() OVER
(PARTITION BY [year], [month] ORDER BY [week])),
WeekOfYear = CONVERT(TINYINT, [week]),
ISOWeekOfYear = CONVERT(TINYINT, ISOWeek),
[Month] = CONVERT(TINYINT, [month]),
[MonthName] = CONVERT(VARCHAR(10), [MonthName]),
[Quarter] = CONVERT(TINYINT, [quarter]),
QuarterName = CONVERT(VARCHAR(6), CASE [quarter] WHEN 1 THEN 'First'
WHEN 2 THEN 'Second' WHEN 3 THEN 'Third' WHEN 4 THEN 'Fourth' END),
[Year] = [year],
MMYYYY = CONVERT(CHAR(6), LEFT(Style101, 2) + LEFT(Style112, 4)),
MonthYear = CONVERT(CHAR(7), LEFT([MonthName], 3) + LEFT(Style112, 4)),
FirstDayOfMonth = FirstOfMonth,
LastDayOfMonth = MAX([date]) OVER (PARTITION BY [year], [month]),
FirstDayOfQuarter = MIN([date]) OVER (PARTITION BY [year], [quarter]),
LastDayOfQuarter = MAX([date]) OVER (PARTITION BY [year], [quarter]),
FirstDayOfYear = FirstOfYear,
LastDayOfYear = MAX([date]) OVER (PARTITION BY [year]),
FirstDayOfNextMonth = DATEADD(MONTH, 1, FirstOfMonth),
FirstDayOfNextYear = DATEADD(YEAR, 1, FirstOfYear)
FROM #dim
OPTION (MAXDOP 1);
--solution
SELECT min(Date)
FROM [Test].[dbo].[DateDimension]
where [year] = 2018 and [Quarter]=4
| Date |
|------------|
| 2018-10-01 |
怎么样
declare @quarter int = 4
declare @year int = 2018
select datefromparts(@year,(@quarter-1)*3+1,1)
或者,如果您仍在使用SQL 2008:
select dateadd(month,(@quarter-1)*3,dateadd(year, @year-2018,'20180101'))
我建议不要使用“-”或“ /”之类的日期分隔符,它取决于区域设置,请使用YYYYMMDD
格式。
declare @quarter int,
@year int,
@date date
set @quarter = 4
set @year = 2018
set @date = cast(@year as varchar(4)) + '0101'
set @date = dateadd(quarter, 1 - 1, @date)
print @date
set @date = cast(@year as varchar(4)) + '0101'
set @date = dateadd(quarter, 2 - 1, @date)
print @date
set @date = cast(@year as varchar(4)) + '0101'
set @date = dateadd(quarter, 3 - 1, @date)
print @date
set @date = cast(@year as varchar(4)) + '0101'
set @date = dateadd(quarter, 4 - 1, @date)
print @date
2018-01-01
2018-04-01
2018-07-01
2018-10-01
db <> 在这里拨弄
'2018-10-01'
独立于区域设置,并且始终会被SQL Server正确解析。那不是真的吗
date
和datetime2
),这是正确的,但对于旧datetime
类型则不正确。因此,作为提问者被铸造date
的格式是罚款在这种情况下
我会完全避免使用字符串,而是将日期算术与已知(甚至未知!)零纪元结合使用。
DECLARE @epoch DATE = CONVERT(DATETIME, 0);
/* for some reason SQL Server let's you cast int to datetime but not to date, the above casts via datetime (second cast implicit) */
SET @date = DATEADD(MONTH, (@quarter-1)*3, DATEADD(YEAR, @year - YEAR(@epoch), @epoch));
这避免了字符串到日期的比较,这比较麻烦,依赖于文化并且昂贵。