Sometimes when working with tables there is a natural value to use as the entry in all but a few cases. The GeneralSparseTable constructor can be used to provide any table type with a default value for entries. See TableXmpPage for general information about tables.
Suppose we launched a fund-raising campaign to raise fifty thousand dollars. To record the contributions, we want a table with strings as keys (for the names) and integer entries (for the amount). In a data base of cash contributions, unless someone has been explicitly entered, it is reasonable to assume they have made a zero dollar contribution.
This creates a keyed access file with default entry 0.
Now patrons can be used just as any other table. Here we record two gifts.
Now let us look up the size of the contributions from Jones and Stingy.
Have we met our seventy thousand dollar goal?
So the project is cancelled and we can delete the data base: