decomp DBCServer_Release and inspect/document database

decomp/schema/GMRustyHearts/procs/CreateCalendar.sql

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+CREATE PROCEDURE [dbo].[CreateCalendar] 
+/************************************************************************************************************
+ Purpose: 
+ Given a start date and an end date, create a calendar of dates that easily traverses months and years.  Is
+ capable of generating up to 179 years worth of calendar by month in any given run. 
+ Usage Notes: 
+ 1.  End date parameter is optional... if not provided, the start date will be used to return that one month.
+ 2.  Of the two input paramters, the lowest (earliest) date will be used as the start date regardless of the
+     order provided. 
+ 3.  Returns a single result set containing all dates. 
+ 4.  Does NOT use a Cursor, While Loop, Temp Table, or Table variable so that even really picky DBA's won't
+     reject the code. 
+ 5.  Because only set-based code was used, returns 10 years worth of calendar in about 230 milliseconds. 
+     A full year takes a scant 76 milliseconds and a single month takes 63 milliseconds. A hundred-year 
+     calendar takes only 6.3 seconds. 
+ 6.  The start date does NOT need to be the first of the month and the end date does NOT need to be the last
+     day of the month.  The internal calculations will "auto-magically" include the whole month for both the 
+     start and end dates as well as all months in between. 
+ Revision History: 
+ Rev 00 - 08/13/2007 - Jeff Moden - Initial creation and unit test. 
+************************************************************************************************************/
+--===== Declare the input parameters 
+        @pStartDate DATETIME,              --Any date (can include time) in the desired start month 
+        @pEndDate   DATETIME = @pStartDate --Any date (can include time) in the desired end month 
+     AS 
+--===== Create the correct environment 
+    SET NOCOUNT ON --Suppress the auto-display of rowcounts to prevent false echos on GUI's 
+    SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED --Same as putting WITH (NOLOCK) on tables in query 
+--===== Create the base date that all the calculations rely on (is a Monday) 
+DECLARE @BaseDate DATETIME 
+    SET @BaseDate = '1753-01-01' 
+--===== Make sure the inputs are in the correct order (start date must always be the earliest date)
+     IF @pEndDate < @pStartDate 
+  BEGIN 
+        DECLARE @Swap DATETIME 
+         SELECT @Swap       = @pStartDate, 
+                @pStartDate = @pEndDate, 
+                @pEndDate   = @Swap 
+    END     
+--===== Modify the start to start on the first of the same month and the end date to end on the last day 
+     -- of the same month. 
+    SET @pStartDate = DATEADD(mm,DATEDIFF(mm,@BaseDate,@pStartDate),@BaseDate) 
+    SET @pEndDate   = DATEADD(mm,DATEDIFF(mm,@BaseDate,@pEndDate)+1,@BaseDate)-1 
+
+--===== Create the calendar without loops, cursors, or temp tables 
+ SELECT MAX(DATENAME(yy,d.TheDate)) AS [Year], 
+        MAX(LEFT(DATENAME(mm,d.TheDate),3))AS [Month], 
+        MAX(CASE WHEN DATENAME(dw,d.TheDate) = '월요일'    THEN DATENAME(dd,d.TheDate) ELSE '' END) AS Mon, 
+        MAX(CASE WHEN DATENAME(dw,d.TheDate) = '화요일'   THEN DATENAME(dd,d.TheDate) ELSE '' END) AS Tue, 
+        MAX(CASE WHEN DATENAME(dw,d.TheDate) = '수요일' THEN DATENAME(dd,d.TheDate) ELSE '' END) AS Wed, 
+        MAX(CASE WHEN DATENAME(dw,d.TheDate) = '목요일'  THEN DATENAME(dd,d.TheDate) ELSE '' END) AS Thu, 
+        MAX(CASE WHEN DATENAME(dw,d.TheDate) = '금요일'    THEN DATENAME(dd,d.TheDate) ELSE '' END) AS Fri, 
+        MAX(CASE WHEN DATENAME(dw,d.TheDate) = '토요일'  THEN DATENAME(dd,d.TheDate) ELSE '' END) AS Sat, 
+        MAX(CASE WHEN DATENAME(dw,d.TheDate) = '일요일'    THEN DATENAME(dd,d.TheDate) ELSE '' END) AS Sun 
+   FROM (--==== Derived table "d" finds all dates for the given range of dates up to 65535 days apart 
+         SELECT YEAR(@pStartDate+n.Number)                    AS TheYear, 
+                MONTH(@pStartDate+n.Number)                   AS TheMonth, 
+                DATEDIFF(dd,@BaseDate,@pStartDate+n.Number)/7 AS TheWeek, 
+                @pStartDate+n.Number                          AS TheDate 
+           FROM (--==== Derived table "n" creates numbers from 0 to 65535 (about 179 years worth of days) 
+                 SELECT t1.Number*256+t2.Number AS Number 
+                   FROM Master.dbo.spt_Values t1, 
+                        Master.dbo.spt_Values t2 
+                  WHERE t1.Type = 'P' 
+                    AND t2.Type = 'P' 
+                )n 
+          WHERE @pStartDate+n.Number <= @pEndDate 
+        )d 
+  GROUP BY d.TheYear,d.TheMonth,d.TheWeek 
+  ORDER BY d.TheYear,d.TheMonth,d.TheWeek
+