Even when the relational version of FileMaker is on the market, you will want to use lookup fields. It's important to have a good command of the ins and outs of lookups. Red Green will match on Green Red. That's true for =Red =Green as well. If you do a match on more than one word, the lookup will return the first match without regard to the order of the words. Use the = to instruct FileMaker to return only whole words that match the string. There is, however, a way to get around this problem.
If you are doing a lookup on the name Smith, if Smithton comes first in the file, that's what will be returned. For example, if a number is formatted as text then 12345 will match 1234 because the 2nd string is contained within the first. If a number is formatted as text, a lookup may find the first number that is a substring of the actual number. This is because of the different way FileMaker indexes text and numeric fields. If the customer number in one file is a number, but defined as text in the other, you may end up with the wrong record. The next problem could be from mixing field types for key identifiers. So, the first rule of lookups might be to make certain you are using a unique identifier. That could be a problem because you certainly may have more than one customer with the same name. If you were to use the customer name instead of the customer number, your lookup would pick up the address information for the first customer in the database with that name. The first is not using a unique identifier. The lookup field basically says, get me the customer address for the first record you find with this customer number in the customer file. Let's say you want to lookup the customer address. You enter the customer number into the invoice file and use that to identify the customer for the lookup. In a relational database, the customer number would be called the primary key, because it is a unique identifier that ties the two fields together. You need to have a common field to identify the customer, in this case a customer number. You need the customer's name and address to print on the invoice, but you don't want to type it in each time. Let's say you have an invoice file and a customer file. This is somewhat analogous to a relation in a relational database and is a powerful feature of FileMaker. A lookup, in FileMaker, is a way to use data from a 2nd file within the primary file. For the moment, lookups are the closest thing to relationality that FileMaker users have at their disposal. One of the most common calls I receive about FileMaker is about lookup fields.
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