MS ACCESS 2003 triggers (Query Event), and Excel import

Question

I am working on a project in a company, and because of such i am bound to use MS ACCESS 2003 operating on XP (although, i don\'t think the OS is relevant here). Because the

Answer 1

Honestly, you might want to ask each of these questions separately. We all have day jobs and can only dedicate a little bit of time to help! :o)

The one question I can quickly answer is the one about data integrity. If you click on Tools and then Relationships, you can set up relationships between your tables. It is in these relationships where you can "enforce referrential integrity". This is where Access will automatically delete records in related tables to keep your data clean.

Answer 2

I agree with user2174085, there is quite a lot in your question.

My approach would be to model your data in classes and use these to write to your database. This would allow you to validate your data as you require, and to import the data into as many tables as you require.

This approach is standard in CRUD applications.

Here is a simple example for illustration purposes with the steps (I hope) clearly described):

1) Define our example database:

Table1: Clients (ID, Name, AddressID)

Table2: Addresses (ID, Street)

2) Define our example spreadsheets:

Clients: ID, Name, AddressID 1, Bob, 1 2, Jim, 2

Addresses: ID, Street 1, Gold Street 2, Derp Street

3) Define our 2 classes which allow us to model a single Client and a single Address.

To use these in MS Access, add a class in the code editor window and paste the below classes in. For more information this is a good vba classes resource:http://www.cpearson.com/excel/classes.aspx

Client class:

Option Compare Database
Option Explicit

Dim intID As Integer
Dim strName As String
Dim intAddressID As Integer

'here we define a query (QueryDef) which is in the database (usp_Clients_InsertRecord), populate its parameters from the class variables and execute it to write the record
Public Sub Insert()
    Dim qdfTemp As QueryDef
    Set qdfTemp = CurrentDb().QueryDefs("usp_Clients_InsertRecord")
    With qdfTemp
        .Parameters("pName") = strName
        .Parameters("pAddressID") = pAddressID
    End With
    qdfTemp.Execute
End Sub

Address class:

Option Compare Database
Option Explicit

Dim intID As Integer
Dim strStreet As String

'here we define a query (QueryDef) which is in the database (usp_Addresses_InsertRecord),     populate its parameters from the class variables and execute it to write the record
Public Sub Insert()
    Dim qdfTemp As QueryDef
    Set qdfTemp = CurrentDb().QueryDefs("usp_Addresses_InsertRecord")
    With qdfTemp
        .Parameters("pStreet") = strStreet
    End With
    qdfTemp.Execute
End Sub

You can perform validation at this point, you could for example create a client record, then call a validate method that tells you if the data is ok.

The reason the ID is not written is because it is an autonumber in the database. It is still included in the class because we may need to create a client / address record from data in the database, and use its information to write another record. For example, to write a client record, we may need to retrieve an address record, complete with AddressID that is used in writing the client record.

4) The above classes use queries (stored procedures) to write to the database, here is an example query:

usp_Clients_InsertRecord

PARAMETERS pName Text (255), pAddressID Long; Insert into Clients(Name, AddressID) Values (pName, pAddressID);

5) This is all well and good, but how do we get our data from excel, into the class, to write it to the database? To do that we use managing classes, these are classes that contain a load of Client or Address records, loaded from the spreadsheet and stored in a collection. This collection is looped over, calling the Insert method to write the records to the database.

This provides an answer to your question of how to write data to tables A, then B then C. You would create 3 classes, populate them with data, then write A to the database, then write B using the ID of the last written record to table A (retrieved using a query) and so on.

Here is an example of a managing class:

Option Explicit
'our clients collection
Private mcolClients As Collection
'adding objects to the clients collection
Public Function AddByParameter(byval Name as string, byval AddressID as integer)
    dim objClient as Client
    Set objClient = New Client
    with objClient
        .strName = Name
        .intAddressID = AddressID
    end with
    mcolClients.Add objClient, Name
end function
'constructor
Private Sub Class_Initialize()
    Set mcolClients = New Collection
End Sub
'you need this to be able to iterate over a collection
Public Function NewEnum() As IUnknown
  Set NewEnum = mcolImportQuestions.[_NewEnum]
End Function
'you can then iterate over the collection, calling the insert method on each record:
public Sub InsertAllClients
    dim objClient as Client
    for each objClient in mcolClients
        objClient.Insert
    next objClient
end function

I think I've gone a bit, if this is useful please let me know / ask questions and I can flesh it out a bit :)