Troubles With Aggregate Functions In Queries And Null Values
Jun 26, 2007
I'm having a problem with queries, and I can't seem to find a solution in books - I looked through about ten of them and none of them addressed the problem. This may be because it has a painfully obvious solution...
A little background:
I am designing a database for a debt-collection law firm. One of the functions it must have is to keep track of various different sorts of financial transactions which can pertain to a given debtor (ie, a received payment, a cost expended, and a few other things).
The problem is that, in generating reports, I need to use queries to find several sums of only those transactions which fall into specific categories (for instance, to calculate the amount a debtor has paid against his balance, it needs to sum only those entries which are both linked to that debtor's ID number and whose type field reads "payment", and then subtract from that those entries whose type field reads "cost"). The problem is this: not all debtors may have "costs" entries, and when there are none, the report comes up blank with a single "#Error" written in the name field and nothing else present.
I believe the problem is that the Sum aggregate is returning a null value when the query finds nothing that meets the criteria. I have been unable to find a way around this; the Nz() and IIf() with IsNull() functions don't seem to be helping.
The query runs as intended when there are entries for every relevant type; however, it is undesired to have to enter a "payment" of $0, "cost" of $0 etc for every entry just so that this function works.
Is there anything I can do about this? Any input would be appreciated, as I'm fairly inexperienced with the use of Office Access. (If it matters, I am using Office 2003).
I have the following query. I got an error when I ran it.
Code: SELECT COUNT([encounter_number] WHERE status = 'Death')/ COUNT([encounter_number]) AS Death Ratio, tbl_test.facility_type AS Type, FROM tbl_test GROUP BY tbl_test.facility_type;
I think the problem is that first WHERE clause inside.
I was wondering if anyone can help me: I have for example Pupils that are being entered into a table (called log). A query then counts the number of entries for each pupil I then want it ONLY to show the pupils that have been entered in 10 times on todays date (using DATE()). I know this doesnt work but this is what I want to do:
SELECT log.pupilNo, log.Forename, log.Surname, Count(log.pupilNo) AS Demerits FROM log, Tally WHERE (log.Date)=Date() AND COUNT(log.pupilNo)>9 GROUP BY log.pupilNo, log.Forename, log.Surname, log.pupilNo;
Apparenty you cannot have an Aggregate function in a where clause. Does anyone know a solution, any help would be appreciated Cheers Bikeboardsurf
Is it possible to add a calcualted field to a query that already uses 'sum'? I want to take the value returned by sum and add the value of another field to it.
Is there any way to lookup items using DLookup or other functions that will return an array of values not just the first value found. Example: I have three employees in a complaint query. I am using Dlookup to identify them on my employee form. When I get to the same employee/employee id on my employees form, I have a label that flashes red to flag me that this employee appears on that complaint query. The problem that I am having is that it only flashes for the first employee found in the query, and the label only flashes for that one person. I would like the label to flash for the other two employees because the function should see that they are in the query results as well. Help please?!!!
I know SQL well enough, but I cant seem to get my query to work. Basically, I am trying to display a series of posts, with the number of comments on the side.
I have two tables, Entries and Comments, which look like this: Entries --------- IDTitleContent (memo field) 1CatsSomething about cats here 2DogsSomething else about dogs here 3RodentsMy pet rat runs in a wheel etc.
Comments -------- IDPostIDComments 11My cat's name is mittens 21I taught my cat how to throw a curve ball 33Rats like squeak toys 42Nobody likes dogs 53Bunnies make good pets 61Cats are witches in disguise Comments.PostID corresponds to Entries.ID on a many-to-one relationship.
I want to run a query that will join the number of comments (which is a Count of each row in the Comments table where Comments.PostID = Entries.ID) to the existing table, so that it will look like this:
Entries (with #ofcomments joined) ---------- IDTitleContent (memo field)#ofcomments 1CatsSomething about cats here3 2DogsSomething else about dogs here1 3RodentsMy pet rat runs in a wheel2 etc.
Usually, this would be a really simple SQL statement, but as I am using a Memo field, I am getting a "cannot use Memo field in aggregate function" error.
I'm not sure what to do, any help would be appreciated :)
Alright, I've got all the pieces to this puzzle, I just can't fit them together properly. I have two tables, tblTickets and tblTicketNotes. They are in a one-to-many relationship, there can be multiple Notes attached to a single ticket. I am trying to set up a query that will pull the first (earliest by date) note for each individual Ticket. Here are the fields from each table that would be of concern here:
tbTickets TicketID - Autonumber - Primary Key Issue - Text - I will be using this later as a criteria to limit with, but not neccessary
tblTicketNotes NoteID - Autonumber - Primary Key TicketID - Long Integer - This is the foreign key of the relationship DateStamp - Date/Time - This is the Note Date, I only want the first (earliest date) one Content - Memo -This is the note information I want
So all I want is the Content of the first/earliest Note for each individual Ticket. I know this should be fairly easy, but I am at a loss.
I am trying to retrieve the last record from a field SampleNumber which is alphanumeric (e.g. "AK005434") and then add a 1 to it as the next SampleNumber. I had previously used a default value in the txtSampleNumber control as
where [Clip] was a field I have calculated in the table to chop off the preceding characters. Adding 1,000,000 and taking the 6 right hand values and concatenating with "AK" gave me the answer, though it is a but primitive.
This all worked until the SampleNumber value got out of order and blocks of SampleNumber values came in that were then followed by blocks of numbers with lower values (say AK005001-AK005050 followed by AK002001-AK002050).
Now I figure if I just recall the latest entry by DLookup and criteria of DMax on the SampleID (Autonumber Primary key) I could get at the value. I have done this to some success using default values in a series of unbound controls like
to get the SampleNumber I require, then a Right function to trim in another unbound box and then use that last unbound box as the default value for the txtSampleNumber control that is the entry for the data table. However, the unbound control box is only valid for the first record and does not update. So, I added a macro that closes the form and reopens it. This all works but is a bit agricultural. I would like to do a single nested function to the default value of the txtSampleNumber control box. Is it possible to nest Right, DLoopkup and DMax into one statement?
i need domain aggregate functions to count the occurrences of specific value in a field, and when it exceeds 1, display null. or 'group by' subqueries with count() to see if you should populate the field or not.
i have checked the forums and i know they kind of answer this question, but im not really sure where i am ment to write it!
I have two queries, which a third query subtracts the 1st query and 2nd query values and gives the end value. If the 2nd value is null, i get a null value at the end, as i need to change this to zero instead. i know i need to use nz (as seen in microsoft access help, and other places on this forum) but im not sure exactly where to put this on my query, and in which query.
I am trying to alter this parameter to bring back all records if either beginningsalesrange or ending salesrange is left blank. I can't quite get it right.
Between [forms]![frmState]![BeginningSalesRange] And [Forms]![frmState]![EndingSalesRange]
I have a table with two fields; Part and remarks - both Text fields containing 1.8 million records. Remarks field has 600,000 blanks in the field. I filtered for blanks to get the 600,000 records displayed. I want to update this field to N/A where null values exist. My code is
UPDATE PartApplications SET PartApplications.remarks = "N/A" WHERE (((PartApplications.remarks) Is Null));
The query updates 55,000 records ONLY and leaves the remaining blank.WHY would all null values not get updated?
I've put in -100 as an arbitrary never possible number. Obviously, this does not return Null values.
Question: How can I return both Null & Numbers when the Textbox in the form is left blank? in all the columns. Currently, I am not getting Null values
Code: >IIf(IsNull([Forms]![MainForm]![Criteria]),SHOW ME EVERYTHING INCLUDING NULL VALUES & NON-NULL NUMBERS,[Forms]![Material Finder]![txtPS])
or in other words
If the textbox is blank, show me all the data available, else if it is not blank then show me only the values that are greater than the number entered in the textbox from within column A, B, C, D ....
i have 2 tables that i am linking on a field that matches with null values on both tables but it either pulls nothing or when i put a right join pulls just one tables data.
i have also confirmed both are pulling from the same data source, so no issues with field properties and confirmed they are null values in each field within both tables.
I am trying to use the expression below to transpose strings of 4-6 numbers (140504) to a string of 8 numbers with "20" in front (20140504). Some of the [Receive_Date] fields are empty or are 0, and in those cases, I need the expression to return a null value.
The Format(...) part of the expression works fine on its own, but I am new to dealing with null values in my expressions, and when I add the rest of the expression, all '#Error' values are returned.
I have a query that performs some calculations, these calculations feed into another query and produce a final value. If there are no null values everything works perfectly. But when there are null values, I get errors.
What I have tried:
1) I tried to implement the Nz function for each field of the formula that is not calculated but from user input.
2) I tried to implement the Nz function for just the field that calculated the last result before feeding into the next query, but it didn't show the 0 value I gave.
3) I tried to use UPDATE TABLE SET in SQL, but I don't think I was using it right. I tried to use it for all records but always got an error when it ran.
The first two above result in showing no values at all, even if there are some. The third didn't work. How to easily update null values in the query to 0? All I could think of was to somehow use Criteria or SQL.
I am currently creating an Access 2007 database for calculating salesperson commissions. I have a table with 5 fields I'm working with: SalesRep, SOWRep, TerritoryRep, Period and Commission. I am trying to build a query that will calculate commission for a salesperson for each record where their name appears in one of the first three fields. Each time their name appears, they get the commission listed in the Commission field for the stated Period. I have managed to do this part successfully. My problem now is that I am creating a query that will sum all of their commissions by Period. I have run into a situation where sometimes a salesperson will not appear in one of the rep fields, resulting in NULL values in the previous queries. How can I create a final query that will sum correctly even if there are NULL values returned on the previous queries?
Here is what I have so far:
November: Avg((SELECT [SumOf1/3GM$s] FROM [BaxterActualMargin1] WHERE [Period] Like "November*")+(SELECT [SumOf1/3GM$s] FROM [BaxterActualMargin2] WHERE [Period] Like "November*")+(SELECT [SumOf1/3GM$s] FROM [BaxterActualMargin3] WHERE [Period] Like "November*"))
I have a calculated field (Bhours) with the following IIf function:
=IIf(Fields!BDate.Value<=Parameters!Pdate.Value and Fields!EDate.Value>Parameters!Pdate.Value,Fields!H ours.Value,0)
It works perfectly, but I don't like the fact that it has a zero for the false part as I like the field to the blanc instead of filled with a zero.I can't use a space as I need to calculate with this field later on. I tried using "", but then the field displays #error".
I am currently working on an instrument datebase, I have a mainquery that takes care of user inputs from a form. The main fields that have been queried on are Type, System, and Manufacturer and they are all look-up fields that contain some null values.
On the same criteria row for these fields, I have
Like IIf([forms]![User Interface].[qtype2]="","*",[forms]![User Interface].[qtype2]) Like IIf([forms]![User Interface].[qsys2]="","*",[forms]![User Interface].[qsys2]) Like IIf([forms]![User Interface].[qman1]="","*",[forms]![User Interface].[qman1])
qtype, qsys and qman are the user inputs from the user interface that returns look-up table values.
This works fine when all 3 of these fields are all filled out for a certain instrument. The problem arise when some fields of the instrument are left blank or is null. The instrument won't show up in a query at all. What I wanted it to do is to show everything including the ones with null fields when the user input are null or "". When the user specifies certain requirement I only want to show the ones that are not null. I understand that putting them on the same row means AND, I have tried to OR them and did not have the result i wanted.
I'm trying to create an expression to calculate percentage.
The fields, Value A and Value B might both have null values, but I do not want Access to treat nulls as zero (as in the Nz() fn). How do I get the expression to exclude any nulls and not calculate for those rows, but set the calculated value for a row with null A or B to zero.
I want it to set no calculated value to zero so I don't get overflow errors and can therefore order the data by the calculated field.
how to return all values in a query when a form critieria is left blank. I have made some progress, the combo box criteria queries were fairly simple, but i'm getting stuck with my date criteria. My query doesn't return null values when I want it to.
I want it to return all records (including null values) if the form OpenFrom and OpenTo dates are blank, and just the values between the selected dates (excluding null values) if the form is completed.
Code: SELECT qryReportSelector2_Authority.*, qryReportSelector2_Authority.ApplicationDate AS ApplicationDateFilter FROM qryReportSelector2_Authority WHERE (((qryReportSelector2_Authority.ApplicationDate) Between Nz([Forms]![frmReportSelector]![OpenFromDate],DMin("[ApplicationDate]","[qryAllCases]")) And Nz([Forms]![frmReportSelector]![OpenToDate],DMax("[ApplicationDate]","[qryAllCases]"))));
I have a query which returns, among other things, a number of boolean fields. In some cases, there will be a genuine True or False value in each of these fields; in others, it can and should be Null (e.g. as a result of a 'failed' LEFT JOIN of some description, where there is no associated record in the joined table which fulfills the criteria)
So something like this :
Code: SELECT [tblTable2].[fldBooleanField].... FROM [tblTable1] LEFT JOIN [tblTable2] ON [tblTable1].[SomeID] = [tblTable2].[SomeID]
However, I will be writing the result of the query to a text file and here's the problem. I want to show a numeric value for a genuine True / False (i.e. -1 and 0 respectively using the standard boolean conversions in Access) and a blank for any Null values.
So I tried this :
Code: SELECT CInt([tblTable2].[fldBooleanField]) AS fldBooleanField.... FROM [tblTable1] LEFT JOIN [tblTable2] ON [tblTable1].[SomeID] = [tblTable2].[SomeID]
However, currently when I look at the exported recordset in Notepad, I am getting 0's for both False and Null values (and -1 for True)
How I can adapt my query to keep Nulls...null? And convert the genuinely present boolean values to integer form?
Only thing I can think of is to use (untested) :
Code: IIf([tblTable2].[fldBooleanField] Is Null, Null, CInt([tblTable2].[fldBooleanField]))
But there's a number of boolean fields in there, all requiring the same treatment.
i'm creating a search form giving the end user a range of controls to use when filtering/searching data. See the image.But, i think my range search (using the textbox) to put in a lower and upper limit...is preventing this from working. In fact, when i put data into all the controls, no data pops up in my subform.
My query data source can also be seen...showing you how i've handled teh null entries. (i need to put in a null 'handler' for the two textboxes?)
It might be an easy one but I just wasted the past hour deciphering through my code in order to solve the run-time error '94' that I'm getting when trying to execute the following code:
Code: Private Sub cmdUpdateDates_Click() '################################### 'This sub aims at combining the timesheet date and the start and end time into the fields [Start Time] and [End Time]. '################################### Dim intCounter As Integer intCounter = 0 Dim rs As ADODB.Recordset
I have a list of product sales for various regions.How do I write a query to only retrieve the record with the highest value in a region, but include the region and product code in the results?For example, If I run an aggregate query using the max function I still get the record for region:
SELECT Stats.ProdCode, Max(Stats.Sales) AS MaxOfSales, Stats.Region FROM Stats GROUP BY Stats.ProdCode, Stats.Region;
I realise that this returns the record for each region because the 'Group By' is applied to that field, but if I remove it then that field is not going to be available in the results(???)
