Thank you mmcdonal for the information towards the subject. May I know a few things. I have three tables lets say Table A with fields;DonorID,Name, ************,Address( primary Key DonorID-datatype "text") , table B with fields; DonorID,UnitNumber,(Primary Key UnitNumber-datatype "text"), C with fields;SerialID,UnitNumber (primary key SerialID-datatype "Autonumber")
Table A is linked to Table B by "DonorID"
table B is Linked to table C by "UnitNumber"
This means that for every record to be complete data must be entered in the three tables. therefore, on downloading I need to down data from the three linked tables.

1. How do I create the Superkey in order to download data from say a laptop computer to update the main database on the main computer or what is the best way to do it?
2. How do I automate this procedure?


Bmulenga

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Bmulenga

You would either need to create a field in each table that is a concatenation of several fields to be your superkey (set to be indexed, duplicates No) or generate the key at runtime as part of your code. It might be easier to store the data, if the size of your database allows this.

In your table, create a field to hold this data. I am troubled that the DonorID is a text field. Do you want to make this an autonumber field? I might also add a DateCreated field and set the default to Date().

Anyway, on your data entry form, put the new field (Call it SupKeyA)and do this code on the Before Insert event (assuming you change DonorID to an autonumber data type):

Dim sKey as String

sKey = CStr(Me.DonorID) & "-" & Me.Name & "-" & CStr(Me.DateCreated)

Me.SupKeyA = sKey

This will add a unique superkey to the record. If you anticipate perhaps changing this person's name sometime in the future, you can also add this code to the Before Update event of the form.

Add this field (Maybe SupKeyA, SupKeyB, SupKeyC) and code to all your data entry forms.

How you update the main database depends on how the users are connecting, or if you are transferring the database file using a memory key, etc. Can you tell me more about how they are doing this?

The idea is that now you can loop through the central TableA, and compare each SupKeyA in the remote database to the SupKeyA field in the main table. If none are found, then copy it over. Then move on to TableB, etc.



mmcdonal