Generating report using IF THEN SQL query - sql

Question

I am having issues getting a SQL statement to work how I need it to. To be honest, I'm pretty green when it comes to SQL so the tries I've attempted have come from copy/paste code that I've tried to edit to make work and it's not running. So what I need is a query to be used for a report in ACCESS.
Here is what data look like:
ID TechID OccurrenceDate OccurrenceName OccurrenceAmt
247 9991 Friday, February 15, 2013 Coaching 4.50
242 9991 Friday, February 08, 2013 Con't Occurrence 0.00
241 9991 Thursday, February 07, 2013 Unscheduled Absense 1.00
240 9991 Wednesday, February 06, 2013 Shift Int less 2 hrs 0.50
243 9991 Monday, February 04, 2013 Unscheduled Absense 1.00
246 9991 Monday, January 21, 2013 Unscheduled Absense 1.00
245 9991 Wednesday, January 16, 2013 Con't Occurrence 0.00
244 9991 Tuesday, January 15, 2013 Unscheduled Absense 1.00
239 9999 Friday, February 08, 2013 Unscheduled Absense 1.00
237 9999 Wednesday, February 06, 2013 Unscheduled Absense 1.00
238 9999 Saturday, February 02, 2013 Coaching 7.00
236 9999 Tuesday, September 11, 2012 Other 6.00
235 9999 Tuesday, September 11, 2012 Other 0.00
228 9999 Thursday, August 23, 2012 Unscheduled Absense 1.00
227 9999 Friday, August 10, 2012 Unscheduled Absense 1.00
226 9999 Wednesday, August 08, 2012 Con't Occurrence 0.00
223 9999 Wednesday, February 29, 2012 Unscheduled Absense 1.00
249 9998 Saturday, February 02, 2013 Unscheduled Absense 1.00
251 9998 Monday, January 21, 2013 Unscheduled Absense 1.00
So basically if there is an "OccurrenceName" of either "Coaching" or "Other" within the last 6 months that amount plus any other occurrences within the previous 6 months should be their Tech Total. If there is are no "Coaching" or "Other" occurrences within the last 6 months then I need to sum the OccurrenceAmount for just the rolling previous 6 months.
Hopefully my very well explained scenario makes sense.
EDIT #1:
Okay, my expected output for this data should be:
TechID Total
9991 4.5
9999 9.0
9998 2.0
So as you can see, for TechID 9991 calculates 4.5 because there was a "Coaching" occurrence and nothing since in the previous 6 months. 9999 would have 9 because there was a Coaching for 7 and two more since then within the previous 6 months bringing that total to 9. 9998 has 2 because that tech has no coaching or anything within the last 6 months so the total is 2.
EDIT #2:
So the only lines that should be counted are the lines that are indented. For 9999, there was a coaching for 7 and 2 more regular occurrences bringing his total to 9. Is that more clear?
EDIT #3:
Okay, got a little further down the road.
#lance - through trial and error I am getting closer... have this for now, but can't get it working:
SELECT tblEmployeeData.TechID, tblEmployeeData.LName, tblEmployeeData.FName, Sum(tblOccurrence.OccurrenceAmt), Last(tblOccurrence.CoachingDate) AS LastOfCoachingDate, tblEmployeeData.SupLName
FROM tblEmployeeData RIGHT JOIN tblOccurrence ON tblEmployeeData.TechID = tblOccurrence.TechID
GROUP BY tblEmployeeData.TechID, tblEmployeeData.LName, tblEmployeeData.FName, tblEmployeeData.SupLName
HAVING (((tblOccurrence.OccurrenceAmt))=IIf([tblOccurrence].[CoachingDate]="",[tblOccurrence].[OccurrenceDate] Between Date() And DateAdd('m',-6,Date()),IIf([tblOccurrence].[CoachingDate]<=DateAdd('m',-6,Date()),[tblOccurrence].[OccurrenceDate] Between Date() And DateAdd('d',[tblOccurrence].[CoachingDate],Date()))));
EDIT #4:
This query is the "best" beginning query I have gotten to work. It pulls over ALL employee data then populates MaxCoaching and MaxDate. So I tried connecting this query to your second query to get totals onto a query and can't get it working.
Query:
SELECT tblEmployeeData.TechID, tblEmployeeData.LName, tblEmployeeData.FName, Max(tblOccurrence.CoachingDate) AS LastCoachingDate, Max([OccurrenceDate]) AS MaxDate, tblEmployeeData.SupLName
FROM tblEmployeeData LEFT JOIN tblOccurrence ON tblEmployeeData.TechID = tblOccurrence.TechID
GROUP BY tblEmployeeData.SupLName, tblEmployeeData.TechID, tblEmployeeData.LName, tblEmployeeData.FName
So these results get the most recent Coaching Date (if any) and the most recent event date so I need to sum Occurrences based on 2 conditions:
If there is a coaching/other date within the last 6 months, it needs that occurrence total from that line PLUS any other dates that have occurred after their coaching/other date
If no coaching/other date has occurred within the last 6 months, then I need the total of occurrences within the last 6 months.
Moving closer to getting a working query! Thanks for your help

Answer 1

#Zamael if I understand your question and the clarifications, the reason 9998 sums to 9, is that the September dates are more than 6 months ago, and that there is another line item with an OccurenceAmt of 2 that we don't see in the table.
Assuming that's correct, I suggest that you create a query with the following SQL:
Select TechID,
SUM(IIF([OccurenceName] in ('Coaching','Other'),1,0)) as CoachingOtherCount,
SUM(IIF([OccurenceName] in ('Coaching','Other'),OccurenceAmt,0)) as CoachingAmt,
SUM(IIF(IIF([OccurenceName] in ('Coaching','Other'),0,OccurenceAmt))) as MiscAmt
From TableName
Where OccurenceDate > = DateAdd("m",-6,Date())
Group By TechID;
Then, Create a second query with following SQL:
select TechID,
IIF(Nz(CoachingOtherCount,0) > 0, CoachingAmt, MiscAmt) as SumOccurenceAmt
from Query1;
EDIT 1 - After Clarification
What I understand now is:
Step 1: Find "Coaching" or "Other" in past 6 Months. If exists goto 2, else goto 3.
Step 2: Sum All lines occurring on or after the earliest from Step 1.
Step 3: Sum all lines from past 6 months.
If this is what you're looking for then the following code will work.
SELECT TechID,
MIN(IIF([OccurrenceName] in ('Coaching','Other'),OccurrenceDate,NULL)) AS MinCoachingOtherDate,
MIN([OccurrenceDate]) AS MinDate
FROM tblOccurrence
WHERE OccurrenceDate >= DateAdd("m",-6,Date())
GROUP BY TechID;
Then, in the second query
Select tbo.TechID,
SUM([OccurrenceAmt]) as Amount
From tblOccurrence tbo
LEFT JOIN QUERY1 q on q.techid = tbo.techid
WHERE tbo.OccurrenceDate >= IIF(q.MinCoachingOtherDate IS NULL, q.MinDate, q.MinCoachingOtherDate)
GROUP BY tbo.TechID;
The first query finds the earliest date for Coaching/Other in the first column if it exists, and simply the earliest date in the second. Then, in the second query we assume the Coaching/Other date unless it is null, then we default to the second date. Because the where constrains the dates dynamically for each TechID, you can just sum all of the OccurenceAmt.