Some simple coding modifications
Now we'll add some C/AL code to objects we've created for our WDTU application.
Adding field validation to a table
In Chapter 4, Pages - the Interactive Interface, we created Table 50010 - Radio Show Fan. We've decided that we want to be able to use this list for promotional activities, such as having drawings for concert tickets. Of course, we want to send the tickets to the winners at their mailing addresses. We didn't include those fields originally in our table design, so we must add them now. To keep our design consistent with the standard product, we will model those fields after the equivalent ones in Table 18 - Customer. Our updated Table 50010 will look like the following screenshot:

Part of modeling our Table 50010 - Radio Show Fan fields on those in Table 18 - Customer is faithfully copying the applicable properties. For example, the TableRelation property for the Post Code
field in Table 18 contains the following lines of code, which we should include...