Forgive me if this has already been asked- I can’t seem to find a well written answer.
I am developing a small application for personal use.
Essentially what I have is two forms. Form 1 is a master view of all my contacts listed on a data grid view. Form 2 will be loaded on the cell/row double click of a particular record in order to edit it’s details.
My question is, what is the best practice/method for achieving this? I have seen many different methods.
Should I:
Pass only the primary key of the selected row then populate the fields on form 2 load
Pass all fields as a variable within a class then populate form 2 from that
Maybe I’m headed in the complete wrong direction though.
I have tried both ways, but wondering what the best method is for scalability.
My personal preference would be to pass a datarow into the opening argument of the form (rather than the PK / all the variables). You can then use the datarow inside your Form2 to bind to your controls or set their values, whichever you think is appropriate.
There are some useful examples on working with a datarow if you're unsure, alternatively you can also check out Microsoft Docs.
Public Sub New(ByVal row As DataRow)
InitializeComponent()
' your code for working with row here
End Sub
Edit:
In terms of "Binding" vs "Setting", you can either have your controls linked to your data to be two way (as you edit the data in a control at run time you alter the data in your database) or you can just set the values of the controls.
E.G. TextBox1.Text = row(0)("ColumnName")
You can find more on data binding on the Microsoft Docs page
Related
This is probably a dumb question, but I'm a noob, so forgive me. I have two tables with a one to many relationship based on a OrderNumber. Essentially, I have some order details in one table, including OrderNumber (the one side of the relationship) and I am trying to get a list of LotNumbers in the other table using the OrderNumberLot (the many side) to link them together, as there can be many lot numbers on one order. The primary key in tblOrderDetails is OrderNumber and the primary key in tblLotNumber is LotID (auto number), but the linked field is OrderNumberLot. I made a open form button located on frmOrderDetail to open frmLotNumbers (based on the tblLotNumber). The deal is when frmLotNumber opens the OrderNumberLot field is blank. I understand there is no associated record in tblLotNumber, because I am trying to enter it, but how do I get the OrderNumber from the previous form, frmOrderDetail, with the button to automatically populate in the OrderNumberLot field in frmLotNumbers? I certainly don't want people to have to type it, because they will screw it up as badly as I have this explanation of my question! Thanks in advance for the help.
I agree with June7 on using a subform-approach for your purpose.
If you already have created the form, you could simply drag it from the sidebar onto your mainform and set the "Link Master Fields" and "Link Child Fields" to "OrderNumber" and "OrderNumberLot" - or you just use the subform-wizard and follow its instructions.
Though, some people dislike subforms in general and try to avoid them whenever possible - which might make sense at further stages of development. Instead of subforms, you could then use vba to transfer information from one form to another.
Lets say your button is named bt_openform
Private Sub bt_openform_Click()
'Open the desired form. The option "acFormAdd" forces the form
'to add a new entry whenever loading and requerying.
'As we want to add a new record, we will not use the filter settings
DoCmd.OpenForm "frmLotNumber", , , ,acFormAdd
'Next, store information from the initial form into the newly opened form
'To refer to data from the current form (meaning the one, in which the Sub is triggerd),
'you can use "Me.fieldname" and to refer to another form, use "Forms!formname!fieldname"
Forms!frmLotNumber!OrderNumberLot = Me.OrderNumber
End Sub
You could also do it the other way around and retrieve the information when loading the form:
Private Sub Form_Load()
Me.OrderNumberLot = Forms!frmOrderDetail!OrderNumber
End Sub
To be on the safe site, one might want to nest this function in an if statement, to check whether frmOrderDetail is open or not. This way, you can open your frmLotNumber from different forms without causing troubles
If CurrentProject.AllForms("frmOrderDetail").IsLoaded Then Me.OrderNumberLot = Forms!frmOrderDetail
The 1,500 page Access 97 Bible (don't laugh!) that I've been given by my boss to solve his problem doesn't solve my problem of how to solve his problem, because it has nee VBA code.
Let me first make clear that I've made attempts to solve this without (much) coding, and that I've coded quite a bit in VBA already, so I'm basically familiar with most things including recordsets, queries, etc etc but have problems with MS Access limits on how to form a report with data coming from VBA variables. I'm also versatile in most programming languages, but this is not a language problem but rather a "how to/what's possible" problem.
My problem right now is that dragging the query fields into the Detail subform and putting them into cells in columns setting Left and Top with VBA code are moving them alright, but each cell is on a new page. Unfortunately, there is multiple data in each cell that won't conform to the Create Report Guide options available.
So my question is simply this: Can someone point me to working examples of code that create, place, and fill with VBA variable strings, text fields at any coordinate I please on a paper size of my choice?
Edit: The above is not an option, as I understand this will prohibit the client from getting an .mde database. What remains, then, is to merely ask for some sound advice on how to get several rows GROUPed BY weekday and machine (see below) into a recordset or similar for each cell. I guess the best way is to count the number of columns in the table (machines in the sql result) and create 5 rows of these with dummy data, then go through the result rows and place the data in the relevant controls. But if you have ideas for doing this work better and faster, write them as answers.
Sorry for this, I knew there was something I wasn't understanding. Basically, I thought Access supported creating reports dynamically via VBA, ie. "generating pages with data" rather than "preparing a flow of controls connected to datasources". But Access requires that you create an ample amount of dummy, unlinked controls manually, then either fill or hide them and that's how they become "dynamic".
This is for Access 2003 on a remote server accessing local and remote ODBC SQL database tables, if relevant. The goal is to make a week schedule of n columns (n=number of machines at a certain plant) x 5 rows (weekday Mon-Fri), and put 1 or more recordset rows (=scheduled activities for that day on that machine) in each of the "n by 5 table" cells.
If you detect venting frustration in this post I can only ask your forgiveness and hope for your understanding.
So, has many techniques for this:
Ex: 1) using dinamic sql for this:
'Create a function to make sql query
Function MakeMySQlReport(Parameters):
Dim strSql as string
Dim strMyVar as string
strsql = vbnullstring
strsql = "Select " & myVar1 & " as MyFieldVar1, * from myTable where Fieldx =" & Parameters
MyReport.recordSource = ssql
End Function
Ex: 2) create function that returns yours strings:
Function MyString1() as string
MyString1 = 'ABC'
end Function
An in your report, select the textbox will receive the value and type =MyString1()]
I hope this help to you, need more examples?
Solution:
Create many objects manually (grr!)
name them systematically
put them in a Control Array (get all Me.Controls, sift out the ones you're interested in, and put them in an indexed array)
go through the array and change their properties
Creating a simple UI using MS Access, hoping to do minimal actual coding (actually helping a friend who is not a coder).
Simplified requirement: Single table, primary key is phone number, lots of other non-mandatory fields. Display a form allowing just the phone number to be entered, if a record with that key exists display the full record, if a record with that key does not exist bring up an form allowing the other fields to be entered for this phone number and hence create a new record.
Q1: Any simple way to achieve this kind of function? Example?
We've got some of this going with a standard form, can execute code if insertion fails, but a standard dialogue box is displayed warning about the duplciate key violation.
Q2: How can we trap that attempted insertion, avoid having the dialogue come up?
You will have to get your hands dirty and write some code to get this outcome. A starting point would be something like this presto code. Post back if you get stuck on any of the parts.
If fCheckIfRecordExists(lYourKey)=True then
Docmd.OpenForm “frmEditExistingRecord”
Else
Docmd.OpenForm “frmEnterNewRecord”
End if
Public function fCheckIfRecordExists (lYourKey as Long) as Boolean
‘Code to check if a record exists, simple method is to use dLookup or a count SQL statement with the criteria as the key you are trying to find
End function
EDIT:
First things first make a form with 1 text box called txtPhone_number and a command button called cmdSearch.
Next put this bit of code in the module behind the form
Public Function fDoes_record_exist(strPhone_number As String) As Boolean
If DCount("Phone_number", "tblYour_table", "Phone_number=" & strPhone_number) > 0 Then
fDoes_record_exist = True
Else
fDoes_record_exist = False
End If
End Function
Next you need to put some code behind the click event of the command button. This code can be expanded on to check for a valid phone number later if you want
If fDoes_record_exist(Me.txtPhone_number) = True Then
DoCmd.OpenForm "frmShow_existing_record"
Else
DoCmd.OpenForm "frmEnter_new_record"
End If
That should set you on your way nicely but post back if you run into problems
Here is an overview of the process with Access logic:
You need an unboud control labelled Phone in the form header, where user will be able to enter the phone number to search. You need to use the After_Update event of that control to trigger your search. There will be a second Phone control, bound this time, in the Detail section of the form for effective data entry/update.
Use the Form_Error event to intercept the error message when user tries to save a duplicate key, in order to display a nice message, and eventually Cancel his changes.
The advice from Kevin Ross to use VB Code is clearly one approach, and I think is appropropriate if we anticipate less trivial requirements in future. However I'm in a situation where I'm helping someone with zero coding background and hence if possible I'd prefer to let them use simple Macros rather than full-scale VB.
As it happens the functionality I require can be implemented with just Macros, and it depends on the suggestion from iDevelop.
The outline of the solution I used:
Create an InitialEntry form with no association to any particular table, it has:
a data entry field for the telephone number
a read-only text box where I can display a message
a button labelled Add
a button labelled Show
I write three macros:
A macro AlreadyExists that displays a message saying "We already that one"
A macro NewEntry that opens a data entry form for my table, in Add mode, and which copies the phone number from InitialEntry!TelephoneNumber
A macro TestForExisting this uses a condition
DCount("*","MyTable","[PhoneNumber] = [FormPhoneNumber] " ) > 0
to control whether to execute AlreadyExists, and a similar test to control whether to call NewEntry.
While this is not as efficient as VB, it does seem to be understandable by a non-coder, so at least we can implement our application.
Ok so I hope the title of the question matches what I about to ask, but here is what I am trying to get at:
So I have an access database that uses a number of unbound forms, and the purpose of the forms are to collect data and save to various tables with VBA click events using SQL statements (INSERT or UPDATE based on whether the ID of the record is present on the form in a hidden text box). When entering a new record (via INSERT), I get the row number with
MyRow = db.openrecordset("SELECT ##Identity")(0) 'thanks David
So you maybe getting the picture. If I have another form that relates to the first form in terms of the record, I just open a recordset and pass that value to another hidden text box.
So my question is, is there a better way to do this regarding passing that value (or just using that value) using a variable instead of this awkward method. So I realize a lot of folks are going to go with the obvious answer of, "Why not just make your forms bound instead of all this code"...and I am sure that is a valid answer, however I inherited this database which was already put together like this, and re-structuring it would be a daunting task.
Any and all advice, or learning resources are greatly appreciated, as they always are!
I use unbound controls on forms for all these kinds of values. The current solution of using an unbound form is sounder than using global or form level variables. If I recall the details correctly while debugging code and you hit the stop button you lose all global or form level variables. Or if the user hits an unhandled error.
Have you looked at OpenArgs?
DoCmd.OpenForm "Form1", , , , , , "Hello"
So how can I pass a value from one form to another? For example: The user select's an organization from a list and this opens up a trip form that allows a user to enter various information regarding the trip. At one place I would like to add another little pop up form where they can enter contact information (just a name and phone for POC) of the organization they are visiting.
So when that initial form opened from the selection screen it has two IDs that are simply hidden in text boxes (one being the tripID, and the other being the OrgID), so how do I pass these to the second little pop up form so that the contact information has the relative IDs with it.
Thanks.
The best approach in these cases is not to attempted to pass a bunch of variables. It is too much code, and is inflexible. For example, if you need to pass two values, what happens over the years when that requirement grows to 5 values? Trying to maintain and pass a whole whack of values is too much coding work.
Keep in mind that each form in ms-access is really a class object that you can manipulate in code. So, use a object approach here and you find you not only write less code, but your code will be more clean, more modular, no need for global vars, and code you write can often be re-used between different forms.
Here is how:
In general when one form launches another form in the 2nd form in the forms on-open event (in fact, you can even use as late as the on-load event) you can pick up a reference to the PREVIOUS form object. In other words, you can use a object approach here.
At the forms module level, for form I declare a form object as:
Option Compare Database
Option Explicit
dim frmPrevious as form
Then, in the forms on-load event, we go:
Set frmPrevious = Screen.ActiveForm
Now, any code in our form can FREELY use code, events, even varibles declared as public from that previous form in code.
So, if you want to force a disk write of the previous form, and re-load of data.
frmPrevious.Refresh
If you want to set the ID value, then go:
frmPrevious!ID = some value
And, note that you can even declare form previous as a PUBLIC variable for that form, and thus if you two forms deep, you could go:
frmPrevious.frmPrevious!ID = some value
So, simply declare a forms object in EACH forms code module (or at lest the ones where you need to use values in code). The above means any code has a ready made reference to the previous form object. Functions declared as public in a form will become a METHOD of the form, and can be run like:
frmPrevious.MyCustomRefresh
or even things like some option to force the previous form to generate and setup a invoice number:
frmPrevous.SetInvoice
or
frmPrevious.SetProjectStatusOn
So not only can you shuffle values and data back and forth, but you can easily execute features and functions that you build in code for the prevous form.
In fact as a coding standard, MOST of my forms have a public function called MyRefresh.
Note that the beauty of this approach is that you can thus read + use + set values from that previous form. This allows your code to not only receive values, but also set values in that previous form. So this approach is bi-directional. You can shuffle data and values back and forth between the forms. The other advantage here is you NOT restricted to just variables, but can use fields, control values (events, properties) etc.
This approach means that much of the previous form is now at your fingertips.
So don’t try to pass a whole whack of variables. Pass a reference to the form and you have a nice ready made object at your fingertips and it makes this type of coding problem a breeze.
The usual way would be to reference the textboxes in the initial form from the popup form, like this:
Forms!frmInitialForm!tripID
Forms!frmInitialForm!OrgID
However, this tightly binds the popup form to the initial form, so that it cannot be used anywhere else in the application.
A better approach is to use OpenArgs:
DoCmd.OpenForm "frmPopup", OpenArgs:=Me.tripID & ", " & me.OrgID
This places your two values into a string, which is passed to the popup form. You can then parse the two values out of the OpenArgs using the Split function.
For more info about passing parameters using OpenArgs, see:
http://www.fmsinc.com/free/NewTips/Access/accesstip13.asp
This one could help
MS Access: passing parameters from one access form to another