Zrobiłem to (tylko dla VEvents, nie wspierając przedmiotów TODO, czy wpisów do Journal lub czegoś w tym stylu). Moja implementacja wygląda następująco (po usunięciu kolumny, które nie są specyficzne dla pytanie):
-- One table for each event. An event may have multiple rRules.
Create Table [vEvent]
(vEventID Integer Identity(1, 1) Not Null
Constraint [vEvent.pk]
Primary Key
Clustered
,title nVarChar(200) Not Null);
-- One table for rRules.
-- My application does NOT support the "bySetPos" rule, so that is not included.
Create Table [rRule]
(rRuleID Integer Identity(1, 1) Not Null
Constraint [rRule.pk]
Primary Key
Clustered
,vEventID Integer Not Null
Constraint [fk.vEvent.rRules]
Foreign Key
References [vEvent] (vEventID)
On Update Cascade
On Delete Cascade
,[class] varChar( 12) Not Null Default('public')
,[created] DateTime Not Null Default(getUTCDate())
,[description] nVarChar(max) Null
,[dtStart] DateTime Not Null
,[dtEnd] DateTime Null
,[duration] varChar( 20) Null
,[geoLat] Float Null
,[geoLng] Float Null
,[lastModified] DateTime Not Null Default(getUTCDate())
,[location] nVarChar(max) Null
,[organizerCN] nVarChar( 50) Null
,[organizerMailTo] nVarChar(100) Null
,[seq] Integer Not Null Default(0)
,[status] varChar( 9) Not Null Default('confirmed')
,[summary] nVarChar( 75) Null
,[transparent] Bit Not Null Default(0)
,[freq] varChar( 8) Not Null Default('daily')
,[until] DateTime Null
,[count] Integer Null
,[interval] Integer Not Null Default(1)
,[bySecond] varChar(170) Null
,[byMinute] varChar(170) Null
,[byHour] varChar( 61) Null
,[byDay] varChar( 35) Null
,[byMonthDay] varChar(200) Null
,[byYearDay] varChar(3078) Null
,[byWeekNo] varChar(353) Null
,[byMonth] varChar( 29) Null
,[wkSt] Char ( 2) Null Default('mo'));
-- Class must be one of "Confidential", "Private", or "Public"
Alter Table [rRule]
Add Constraint [rRule.ck.Class]
Check ([class] In ('confidential', 'private', 'public'));
-- Start date must come before End date
Alter Table [rRule]
Add Constraint [rRule.ck.dtStart]
Check ([dtEnd] Is Null Or [dtStart] <= [dtEnd]);
-- dtEnd and duration may not both be present
Alter Table [rRule]
Add Constraint [rRule.ck.duration]
Check (Not ([dtEnd] Is Not Null And [duration] Is Not Null));
-- Check valid values for [freq]. Note that 'single' is NOT in the RFC;
-- it is an optimization for my particular iCalendar calculation engine.
-- I use it as a clue that this pattern has only a single date (dtStart),
-- and there is no need to perform extra calculations on it.
Alter Table [rRule]
Add Constraint [rRule.ck.freq]
Check ([freq] In
('yearly'
,'monthly'
,'weekly'
,'daily'
,'hourly'
,'minutely'
,'secondly'
,'single')); -- Single is NOT part of the spec!
-- If there is a latitude, there must be a longitude, and vice versa.
Alter Table [rRule]
Add Constraint [rRule.ck.geo]
Check (([geoLat] Is Null And [geoLng] Is Null)
Or ([geoLat] Is Not Null And [geoLng] Is Not Null));
-- Interval must be positive.
Alter Table [rRule]
Add Constraint [rRule.ck.interval]
Check ([interval] > 0);
-- Status has a set of defined values.
Alter Table [rRule]
Add Constraint [rRule.ck.status]
Check ([status] In ('cancelled', 'confirmed', 'tentative'));
-- Until and Count may not coexist in the same rule.
Alter Table [rRule]
Add Constraint [rRule.ck.until and count]
Check (Not ([until] Is Not Null And [count] Is Not Null));
-- One table for exceptions to rRules. In my application, this covers both
-- exDate and rDate. I do NOT support extended rule logic here; The RFC says
-- you should support the same sort of date calculations here as are supported
-- in rRules: exceptions can recur, etc. I don't do that; mine is simply a
-- set of dates that are either "exceptions" (dates which don't appear, even
-- if the rule otherwise says they should) or "extras" (dates which do appear,
-- even if the rule otherwise wouldn't include them). This has proved
-- sufficient for my application, and something that can be exported into a
-- valid iCalendar file--even if I can't import an iCalendar file that makes
-- use of recurring rules for exceptions to recurring rules.
Create Table [exDate]
(exDateID Integer Identity(1, 1) Not Null
Constraint [exDate.pk]
Primary Key
Clustered
,rRuleID Integer Not Null
Constraint [fk.rRule.exDates]
Foreign Key
References [rRule] (rRuleID)
On Update Cascade
On Delete Cascade
,[date] DateTime Not Null
,[type] varChar(6) Not Null); -- Type = "exDate" or "rDate" for me; YMMV.
Aby przejść wraz z tym, mam kilka SQL Server 2005+ CLR funkcje, które mogą być używane do obliczania daty dla różnych wydarzenia. Znalazłem następujące formularze, które mogą być bardzo przydatne:
Select * From dbo.getDatesByVEventID(@id, @startDate, @endDate)
Select * From dbo.getEventsByDateRange(@startDate, @endDate, @maxCount)
Wdrożenie powyższego jest cholernie zabawne, aby dowiedzieć się!
wiem, że to jest ponad 7 lat życia, jest to nadal, jak podejść do tego, I zrobić nowszą wersję SQL daje żadnych opcji lepiej odpytywanie? –