- Create an address book with names and addresses that are correctly input into your database. Use the ZIP code (the five-digit ZIP + 4 format) portion of the address. In design view, the table will show the fields and the various attributes. All fields can be text, but to ensure data integrity, set the ZIP code field to 10 characters. Next, under Input Mask, type "00000\-9999;;_" This ensures the first five digits go in the first five positions and, if a plus four ZIP is included, it will take its place at the end. If a letter of the alphabet is attempted in that field, it will simply not take it. For other situations, the caption can be made to put up a message informing the database user that it is the wrong type of input. For example, a field might be a telephone number. If alpha letters are input, it will suggest that only numbers from 0 and 9 can be input there. This also has value in that it will ensure that the correct data is input into each table, so the data will not need to be cleaned up later on.
- Sometimes a field can be too long or too short. Under certain circumstances, it is imperative to limit it to a specific length. Also, a validation field like this can be useful for creating code blocks, where the field length is tightly controlled. The following validation mask will achieve a field of exactly eight numerals, no more and no less: Is Null or Like "????????" (The question mark means anything letter or numeral goes in there. If it had to be numbers, the hash sign "#" would be used.)
- Create neat fields with the correct data by using validation in the input mask. Other examples of validated input are dates, times, social security, phone numbers and passwords which have a starred display to avoid the password being read while it is being entered. Although there are some limitations. However, it is important to note that the input mask in MS Access only works with Text or Date/Time field types.
