How to add new year? - coldfusion

Question

I would like to increment school year every time after previous school year is over. For example my current code looks like this:
WHERE schooldt BETWEEN '07/01/2016' AND '06/30/2017'
So once school year is over 06/30/2017 I would like to set new start date and new end date automatically. I was thinking about using dateAdd() in cold fusion. Is there any other way to do this and what would be the most efficient?
Thanks in advance.

Answer 1

I would like to increment school year every time after previous school year is over
Then implement logic that changes the date values used in your query based on the current month. If the current month is earlier than July, then you know the current school year is still in progress. So deduct one year to calculate the start date. Otherwise, move to the next year.
<cfset today = now()>
<!--- If the current school year is still in progress --->
<cfif month(today) lt 7>
<cfset startDate = createDate( year(today) - 1, 7, 1)>
<cfset endDate = createDate( year(today), 6, 30)>
<!--- Otherwise, move to next year --->
<cfelse>
<cfset startDate = createDate( year(today), 7, 1)>
<cfset endDate = createDate( year(today) + 1, 6, 30)>
</cfif>
As far as querying, two things to keep in mind:
Date strings are ambiguous. Always use date objects instead.
Be careful with date comparisons and the BETWEEN operator. If the SchoolDt column contained both a date and time, the result may not be what you expected. A more flexible construct (that stills works even if a column contains both date and time) is:
WHERE SchoolDt >= <cfqueryparam value="#startDate#" cfsqltype="cf_sql_date">
AND SchoolDt < <cfqueryparam value="#dateAdd('d', 1, endDate)#" cfsqltype="cf_sql_date">
If you are using new Query(), parameterize the sql string and use addParam instead:
yourQuery.addParam( name="startDate"
, value="#startDate#"
, cfsqltype="cf_sql_date" );
yourQuery.addParam( name="endDate"
, value="#endDate#"
, cfsqltype="cf_sql_date" );

Answer 2

For the date table answer:
CREATE TABLE calendar (
SeqNum int
, schooldt date NOT NULL PRIMARY KEY
, theYear int
, theMonth tinyint
, theDay tinyint
, schoolyear int
, isSchoolDay tinyint /* Can count schooldays */
, isHoliday tinyint /* Can count holidays. */
)
DECLARE #StartDate date = '1/1/2010'
/* Build tally table with 10^x rows */
; WITH TallyTable (x) AS
(
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) a(x) -- 10 days
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) b(x) -- 100 days
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) c(x) -- 1000 days
CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) d(x) -- 10000 days
)
INSERT INTO calendar ( SeqNum, schooldt, theYear, theMonth, theDay, schoolyear, isSchoolDay, isHoliday )
SELECT
tt.x AS SeqNum
, d1.theDate
, d2.theYear
, d2.theMonth
, d2.theDay
, d2.theSchoolYear
, 1 , 0 /* Defaults for isSchoolDay and isHoliday. Add if needed. */
FROM TallyTable tt
CROSS APPLY (
SELECT theDate = DATEADD(dd, (tt.x-1), #StartDate) /* Starting date */
) d1
CROSS APPLY
(
SELECT theYear = DATEPART(yy,d1.theDate)
, theMonth = DATEPART(mm,d1.theDate)
, theDay = DATEPART(dd,d1.theDate)
, theSchoolYear = CASE WHEN DATEPART(mm,d1.theDate) < 7 THEN DATEPART(yyyy,d1.theDate) ELSE DATEPART(yyyy,d1.theDate)+1 END
) d2;
Something along those lines will give you a list of days for several years out. Then you can join on this table to get the range that you want.
To improve the table, you can include information to label Holidays and Weekends, so that you only see days that school is actually in session. And most importantly, you can filter it all by the current school year that you wish to see. You don't have to worry about incrementing the school year when it's time to change.
But it again begs the question, what is your ultimate goal of this query? There may be even better ways to accomplish your ultimate goal.