Comming up with one field to relate a record with transactions
I am in the process of combining 3 separate MS Access databases into one large SQL database. I have had several requests to create one account for each user and then have all of their activity in another tables which makes sense... A challenge that I am facing is that we are a telemarketing operation and rent outside lists for one time use. If we make the sale, they become our customers and we can use them as much as we please. I am having a hard time comming up with a field that I can use to relate each transaction with the appropriate customer. The data can come in one of three different ways:
1.) telemarketing sales where a phone number is required
2.) website where an email address is required
3.) phone order where we get an address and name of contact
Any ideas of a way I can come up with one field that would be good to use for this situation?