tldr: Can not update records from query because of aggregate functions. What workarounds do you suggest?
I have a table containing decision criteria to which a user can assign a relative weight. I calculate the absolute weight in an SQL query using an aggregate function (as described here Divide the value of each row by the SUM of this column).
qryDecisionCriteria
name relative_weight absolute_weight (calculated)
price 2 50 %
quality 1 25 %
experience 1 25 %
I would like to present the query result in a form, where the user can update the relative weights, and then sees the absolute_weights.
However, the query results are not updatable, because the query involves an aggregate function.
What alternative methods or workarounds could I use, so that a user can edit relative_weights and view absolute_weights as a kind of visual feedback?
I read about temporary tables here http://www.fmsinc.com/MicrosoftAccess/query/non-updateable/index.html but I'm not sure, how to implement this.
Maybe I could also create an additional "edit form" based on a simple query, that is automatically invoked when the user selects a record in qryDecisionCriteria data?
Or maybe just display data from two queries (one updatable, one with the calculated field) next to each other in the form?
Which options would you recommend and why?
Make the Record Source for the form the updatable base query. In the text box which shows the calculated absolute weight set the control source to
=DSum("relative_weight","<base table name>")/Forms!<Form Name>!relative_weight
You'll need to be sure that you do two things with this
When you drag fields onto a form in Access it makes the name of the control the same as the control source column. this is really annoying and can cause a lot of headaches. Rename your control to something like txtColumnName. That way Forms!<Form Name>!relative_weight is guaranteed to reference the field and not the textbox.
in the AfterChange event for the relative_weight textbox you should add an event handler in which the following code is run
txtabsolute_weight.Requery
This will make sure the formula is recalculated whenever someone changes a weight. Otherwise they need to hit F5.
Related
Perhaps this is beyond the purpose of LinqPad, but does it have this functionality that is available in SQL Management Studio?
I want to seutp some quick data but don't want to have to write code to do it. I just want to type it in.
Yes, provided your tables have primary keys set.
All you have to do is put your results to data grids (Ctrl+Shift+G) then query the table you want to add rows to. If you're just adding rows and don't need to see existing rows, you can filter it out (YourTable.Take(0)). The key is to make sure that the query type is IQueryable<YourTable>.
You will be presented with a grid of the results of the query. There should be a button up top to Edit Data. There should be an empty row at the end (or you could click on Add Row) where you can enter your data.
In several notes applications, instead of handling related data as separate documents, if the size of the data is small (less than the 32k limit), I'll make several multi valued fields and display it in what I call a "List Panel". It's a table where each column displays one multi-value field. Since fielda(1) goes with fieldb(1) that goes with fieldc(1) there is a concept of rows. (I did a similar thing in my auditing routine discussed here )
It is always assumed that each field has exactly the same number of elements.
All the multi-value fields are then stored on the single document. This avoids several coding conventions that made my eyes bleed like having date changed, who changed it, new value fields for each field we wanted to audit. Another thing that this kept to a minimum was having to provide multiple fields for the same thing that locked you into a limit. Taxrate1, Taxrate2, Taxrate3, etc...
In my "Listpanel" the first column is a vertical checkbox. (One for each element in my lists) This is so I can select one item to bring up and edit, or select multiple values to delete "rows" or apply some kind of mass change to them.
What would be the best way to handle this under xPages to get this functionality? I tried making a table but am having the devil of a time to get the checkboxes to line up with their corresponding data items.
Views and dojo-grids seem to assume we're using a document for each row.....
This TableWalker may provide what you want http://www-10.lotus.com/ldd/ddwiki.nsf/dx/Tutorial-Introduction-to-XPages-Exercise-23
It was created when XPages was all very new, so it's SSJS rather than Java. But if you're comfortable wiith Java, converting it probably won't be a challenge.
You could use a repeat control to display the values and build a table using the table row tags in the repeat. You would want to calculate the id of the checkbox to be able to take an action on that selected row. The repeat var would be just one of your multi-value fields and you use the index of the repeat to get the value for that row from the other multi-value fields.
Background
I have two tables:
Projects
EmployeeID
Employee
EmployeeID
Name
I have a query I am basing a form on containing, among other items:
SELECT e.Name FROM Projects p JOIN Employee e ON e.EmployeeID=p.EmployeeID
When I make a form in Access based on this query, I can very easily display e.Name on my form because it is joined from the query.
My real example is of course considerably more complicated than this simple example. The above works fine for read-only queries and scales well. However I would like to use a Splitform view and this becomes very slow with many joins for even small numbers of recordsets. Considering a large percentage of my joins are simple like the above, I am hoping for a way to remove as many as possible.
On the form, e.Name will be read only and not be update-able.
Similar question
In this question I am able to successfully change a combo-box into a lookup. The accepted answer allows a combo box to control Projects.EmployeeID by displaying Employee.Name field in the combo box.
Possible work-arounds
I know one way I could do this is use a combo-box but disable it. This would look a bit weird since it'd have the drop down selector but not be selectable.
Alternatively, I could make it a completely unbound field and write VBA code to update the form each time the recordset changes by running quick queries, getting the text value I am searching for, and updating a label accordingly.
Neither of these are overly appealing, however.
Question
How can I display a single text field on an Access split-form which is the result of a very simple query lookup, based on an ID from the main table field?
You can use Dlookup to return this reference very simply
Construct a Dlookup formula like:
=DLookUp("Name", "Employee", "EmployeeID =" & "[EmployeeID]"
and use this as the ControlSource for the textbox.
Some notes:
The & is important as it binds the formula to the single record displayed on the form
[EmployeeID] refers to the current record displayed on the form. This assumes that "EmployeeID" is included in the query for the form, whether bound to the Projects table or included in the query
I have a VB active report which has many different attributes. The report contains attributes area, balance, id and status and is currently grouped my area. What I need to do now is remove all lines from the report where the balance is equal to 0 and the status equal to deactive. The information for the active report is from my database. Thus I think the best way would be to only select records where the balance is not 0 and status not equal to deactive. Is there a way I can query my database and have the active report be based off the query results? Is there an easy way to do this? Thanks for any help.
Yes, the best way to do this is to change the query so that only the minimum records you need are actually coming into the report. The Modify Data Sources at Run Time topic from the documentation shows how to modify that SQL statement in the code dynamically at runtime.
If you can hard-code the SQL query for the report you should probably just modify the SQL at design time inside the designer. This Bind Reports to a Data Source topic shows you how to do that.
You can also programatically control the visibility of fields/textboxes based on the data using the Format event of the section containing those controls (most likely Detail_Format), but it sounds to me like modifying the SQL query is your best bet.
I have 300+ queries which fetch information from my database. Right now, there is no time condition specified in the queries, so if I wanted to filter all of them by a certain time period, i.e. Between #07/01/2009# And #08/01/2009#, I would have to manually go in each query and add this condition.
All of my queries are populating data into 4 main reports. What I am trying to do is apply a time filtering criteria like the one above to all of my queries at once, so that I can create a weekly report, as well as the Totals report (which just means there's no time condition).
Is there any easy way to add a single parameter before pulling my report that would filter all of my queries at once, and to pull the Totals report if it the parameter field were blank?
You can use a reference to a form control within the WHERE clause of a query. So, for example, if I have an open form named frmDatePicker which includes a text box control named txtStartdate, I could use that control's value as a WHERE condition.
SELECT *
FROM MyTable
WHERE my_date_field >= Forms!frmDatePicker!txtStartDate;
That approach can work, but I have no idea whether it's an appropriate fit for your situation. You would have to modify all of your queries which include that date condition. That could be a one-time-only change. But if you ever change the form and/or control name, you'd have the revise the queries again. (So try not to do that!)
Edit: If you want to allow the user to leave txtStartDate blank, so as not to filter on that date at all, try a WHERE clause like this:
WHERE
my_date_field >= Forms!frmDatePicker!txtStartDate
Or Forms!frmDatePicker!txtStartDate Is Null;