Question

I am creating an application in Microsoft Access. This is for a small database that the customer will run on a desktop. No network of any kind will be involved. All the necessary files to use the database must be on a single desktop computer.

I want to deliver the app to my customer in stages. Most likely I will email the .accdb file to the customer. How do I deliver an update and maintain any data already entered by the customer? Updates may include changes to the table structure as well as to forms.

The answers given to my original question address the issue of changing forms and other UI elements. However, what if I want to add a table or add column to an existing one? How do I seamlessly deliver such changes while preserving as much data as possible on the user’s end?

Answer 1

You absolutely MUST (!) split your database into two parts. A backend part storing the tables (“the database”) and a frontend containing the forms, reports, queries and application logic (“the application”). Link the tables from the backend to the fontend.

The frontend might also contain tables with control paramameters, report dictionaries etc., but no data that your customer enters!

Newer versions of Access have a database splitting wizard.

You might need a code that automatically links the backend to the fontend on the customers site.

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UPDATE

You have two possibilities to alter the schema of your database on the customers PC.

1) Do the Updates through the DAO (or ADOX) object models. e.g.

    Set tdf = db.CreateTableDef("tblNew")
    tdf.Fields.Append tdf.CreateField("fieldname", dbText)
    ...
    db.TableDefs.Append tdf

2) Use DDL queries

    CREATE TABLE MyNewTable (
      ID AUTOINCREMENT,
      Textfield    TEXT(50),
      LongField    LONG,
      ...,
      CONSTRAINT PK_MyNewTable PRIMARY KEY (ID)
    )

Or

    ALTER TABLE SomeExistingTable ADD COLUMN Newcolumn Text(50)