I'm working on attendance management project using access database and it stores the name, attendance status, date and course code of a particular day.
I used myreader.read() condition to check if duplicate date exists and it worked fine but the problem is when I use course code with condition as If myreader.read() and myreader1.read()
Con.close()
Messagebox.show(course and date already present)
and I have course code in a combobox. It works fine for the first time but after that when I change date, it says the course code already present. Is there any way to filter different courses corresponding to a particular date?
Related
I have ran a query is SQL server. there is a name category and every category has a date that it started... however sometimes data was incorrectly entered in the front end so when I do the data pull it returns two start dates per category when in reality just the earliest date should be present. is there any sql code I can throw into this join query that replaces all situations when a category has two dates with the earliest one?
From what I understand, you need to use the MIN() function to get only the earliest entered event when querying your table. You can achieve this my using something similar to the following:
SELECT
categoryName,
MIN(categoryDate)
FROM Category
GROUP BY categoryName
However, I am not sure this is what you need since we have no dataset to verify against. Ideally, you can explain in a more clear way, what you need to achieve, and we can help you better.
I know this should be simple but after hours of googling I am still failing...
I have a vb.net form application. Basically I have an SQL database with an Employee table with an EmpFinish column in datetime, null format (Employee Finish Date). The data is imported from a linked SQL DB (populated from an external app). Any "blank" dates show as 1899-12-30 00:00:00.000 in SQL.
The Employee table data is shown on a datagridview form, a row is selected, then I want to perform a check to test whether that rows EmpFinish date from the form is earlier or equal to today and is not equal to it's "blank" value i.e. has the employee left employment.
Code excerpt:
Dim currentDateTime = DateTime.Now
Dim selectedEmpFinishDate As DateTime =
EmployeesDataGridView.SelectedRows(0).Cells(5).Value
If selectedEmpFinishDate.CompareTo(currentDateTime) <= 0 Then
' code to do
End If
I didn't start out using the CompareTo() above util I started Googling this issue and it seems this is the best way to compare dates. Yes???
This test works for actual dates e.g. yesterday but also catches all 1899 dates, I have tried lots of tests (using 1 If statement of separate ones) to check for the 1899 blank dates but cannot get anything to work. If I debug the code at the test line, selectedEmpFinishDate supposedly equals #12/30/1899#. If I show the field value onscreen via
MsgBox("selectedFinDate = " & selectedEmpFinishDate) it reports as 00:00:00
I know this must be possible but cannot figure it out.
Could someone please offer a solution as I am running out of hair to pull out.
I have followed djv's advice (I had the same thought last night) and done an override to set these date values to NULL. I was then able to use IsDBNull() successfully.
To clarify where these dates came from... Data is imported into this database from another SQL DB created by a huge business software application. Not sure if they want the dates stored this way or whether the import sets them to be this "blank" default 1899 date.
They actually showed on all forms as 1899 etc so resetting them to NULL is the best option all around.
To anyone else who has these 1899 dates I would advise to update them to NULL.
Thank you to everyone who responded especially djv.
I am wondering if some one might be able to assist me with my VB code. I believe I am close, because a lot of the time my code works just fine but I noticed that there might be a weakness to it because at times I get unexpected results. I am thinking I am missing something pretty basic here so bear with me!
Basically, I am trying to create a simple hotel reservation system in a Data Table for a VB project that I created just playing around in my spare time.
What I hope to be able to accomplish is for a user to be able to select a room number from a list box then pick an arrival and departure date. After this happens and they click a button I want the program to be able to compare the Room Number along with the beginning date of the reservation and the end date of the reservation with the room number, beginning Dates and end dates in each row already inside of the Data Table. Anyway, here is basically how my If Statement is structured so far:
For Each data As DataRow In dtRoomReserveData.Rows
If data.Item("RoomNum").ToString.Contains(lstSelectRoomNum.Text) AndAlso data.Item("DateArrive") >= dateArrive.Value.Date AndAlso dr2.Item("DateArrive") <= dateLeave.Value.Date Then
'if there is a reservation in room exists during that Date range display error message to user:
MessageBox.Show("Sorry! That room is already reserved during that date range!")
Exit Sub
End If
Next
Any help offered is greatly appreciated!
So after reading 9 posts about the same error on Stack I didn't really find an answer to my problem, hence me posting this question.
So in my Access I have a query that inherits from several other queries. With this query a User can get information with a certain Date range. This data is put in a report where the records are shown and internally (in the report) some calculation is done of the record fields.
The problem is, when A user wants data until the date 2016-4-22 the report shows up fine. Though when the User wants data until the date 2016-4-30 (from day 23 and on it just gives the same errors) the report tries to load but after a while fails with the error:
This expression is typed incorrectly or it is too complex to be evaluated
So this made me test a few things which I have list down below:
First I thought the Query itself or the given WHERE clause were corrupted / not good so I put the Report recordsource with the WHERE clause in a separate test query and executed it. This all worked fine (no errors).
This made me believe that perhaps a single record was corrupted so I went to the date from which on it gave the error (2016-4-23) and checked this record. Nothing weird was found.
Then I thought it could be some field on the report that was giving the error so I removed several fields and after removing a few Calculated Sum(total) fields the error disappeared.
So I created another query and did the Sum in this query as well based on my created test query - this gave the same error.
After these tests I was pretty sure that perhaps the calculated data was just too much to calculate. I also copied the queries data into Excel and did a SUM of the field there as well. The outcome was roughly 15 million. I can hardly imagine that a number of 15 million is too complex to be evaluated...
Besides that, I also tried to create another SUM query on the specific field but with the date based on 2016-4-22 (so the one that initially DID work). But now it also givers the error on this date... So there goes my theory..
Anyone has a clue what is going wrong?
The 'base' query in question is:
SELECT qryOHW6Verdicht.*
, CStr([nummer] & "." & [qryOHW6Verdicht].[positie]) AS NummerPos
, [ArbeidTot]+[MateriaalTot]+[UitbesteedTot] AS Kosten
, CDbl([AangenomenprijsPositie])+CDbl([MeerwerkPrijsPositie]) AS OpdrachtSom
, IIf([nacalculatie],[Kosten],IIf(IsNull([kostenverwacht]),(100-[otwinstpercentage])/100*[opdrachtsom],[kostenverwacht])) AS VerwachteKosten
, IIf([nacalculatie],[kosten],IIf([Kosten]<[VerwachteKosten],[Opdrachtsom]-[VerwachteKosten],[Opdrachtsom]-[Kosten])) AS VerwachteWinst
, [Kosten]-[VerkoopTot] AS WaardeOHW
, DatePart("yyyy",[gereeddatum]) AS GereedJaar
, [OtOverhead]*[VerkoopTot]/100 AS Overhead
, qryVCBoekingenVerdicht.KostenVerwacht
FROM qryOHW6Verdicht LEFT JOIN qryVCBoekingenVerdicht
ON (qryOHW6Verdicht.[Positie] = qryVCBoekingenVerdicht.[Positie])
AND (qryOHW6Verdicht.[Nummer] = qryVCBoekingenVerdicht.[Offerte])
The report opens with the previous query as recordsource and with this WHERE filter:
1=1 AND (Gereeddatum is null OR Gereeddatum>=#2016-4-30# )
AND Project IS NULL AND NOT (WaardeOHW=0 AND Kosten=0) AND GarantieOrder=0
In the report I got a few Calculated fields and one of them that goes wrong is:
=Sum([OpdrachtSom])
i have a database used at work for evaluating calls, the database is somewhat dated and originally created on Access XP. Once evaluated these calls are given a score out of 5 which is entered along with other data (such as date, employee name, etc) on a form. I have the reports set up so they generate when you enter the employee name and then the start of a date period and the end of a date period, the report will then generate and show the entries made between those 2 dates. i am trying to include a section on the report which shows an average of the call score for the employee for the period chosen. I understand this may be pretty simple but i'm struggling! cheers, Kris
If you want to work out group calculations on reports, you can either put them in the group header/footer, or report header/footer (for calculations over the whole report).
In this case, placing a textbox with something like =AVG([CallScore]) as the control source in the Report Footer should work.
This page should explain more about using aggregate functions in reports: http://office.microsoft.com/en-gb/access-help/summing-in-reports-HA001122444.aspx