DroidDB^® Tip for June 2012

Associating a Name with a Variable

Within your form, you may use variables. By just looking at the variable reference (@var(0), @var(1), etc.), there is no way to really know what kind of data it holds. Is it an employee id? An age? A record counter? You can associate an alias (a.k.a. a name) with a variable.

When entering an expression (such as in an Assign step in a macro), you normally would write an expression like:

     @var(1) + 1

If you wanted to associate an alias with variable 1, DroidDB allows you to write the expression like this:

     @var(1, Age) + 1

The alias ('Age' in this case) can only contain characters, digits, and underscores; must not start with a digit; and be no longer than 15 characters long. DroidDB completely ignores the alias you provide, it is only there for your own documentation purposes. You don't have to provide one of these aliases, but you can if you want to.

Furthermore, you can make these aliases show up in a dropdown list that contains variables. You do this by putting entries in the MyProject.ini file (in the application folder). The entries in the .ini file would look like:

     [Variables]
     0=Name
     1=Age
     2=Address

Again, the alias can only contain characters, digits, and underscores; must not start with a digit; and be no longer than 15 characters long. Please note: these aliases will NOT be checked against the aliases used in the @var(n, alias) expressions.

 

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