Operation Manual

Type in the aliases as they are listed in Figure 250.
Figure 250: Query table with aliases added
3) Run the query again. The results are in Figure 251.
Figure 251: Query run with aliases
We really do not need the column showing the difference between the FuelID fields from the table
and query, so we will hide it. While it will not be visible, it will still be used in the calculations.
4) Hide a column that does not need to be seen.
Remove the check in the box of the Visible cell as in Figure 252.
Figure 252: Making a field invisible in a query run
5) Rerun the query (Figure 253).
Figure 253: Query run with a hidden column
Step 10: Close, save, and name the query.
My suggestion for a name is Fuel Economy.
1) Click the Save icon.
2) Name the query.
3) Close the query.
4) Save the database file.
There are obviously other calculations that can be made in this query such as cost per distance
traveled and how much of the cost belongs to each of the payment types.
Note
To fully use queries requires a knowledge of set operations (unions, intersections,
and, or, complements, and any combinations of these). Having a copy of the
HSQLDB User Guide, available from http://hsqldb.org/, is also extremely useful.
Chapter 8 Getting Started with Base | 253