title: Access: impose referential integrity on a linked table
body: <p>I have two Access databases: <code>Main</code> stores most of my data and <code>Memos</code> stores data of datatype Memo.  I am storing the memos in a separate db because everything I read about Memo fields said they were prone to corruption and that the only safe way to protect your database is to have the memos in a separate linked db.</p>
  
  <p><code>Memos</code> has a table <code>Info</code> with fields:
  <code>ID</code> (type Autonumber primary key)
  <code>Info</code> (type Memo)</p>
  
  <p><code>Main</code> has a table <code>Content</code> with fields:
  <code>ID</code> (type Autonumber primary key)
  <code>infoID</code> (type Number)
  <code>entryDate</code> (type Date/Time)</p>
  
  <p>I want to enforce referential integrity on <code>Content</code> so that it can only accept values that are valid IDs from table <code>Info</code>.  But I can't, because <code>Memos</code> is a linked database.  I can establish controls at another point in the data entry process to ensure that only values from <code>Info</code> can be inserted into <code>Content</code>, but I'd rather not code the validation if there's a way to enforce it through database constraints.</p>
  
  <p>Is there another way to enforce integrity between linked tables that I'm not aware of, or a different way to handle the Memo storage problem so that I can keep the Memos in the same DB?</p>