First of all we create a a polygon extract and save this as a .dra file.
Then we employ a Utility to Extract the data from the database that it was originally associated with.
Select and save .dra
To extract polygon data you can use the query tool, except that this will require there to be an underlying database.
Make sure that you have selected the Default tab as an On-Hit option, in the data Link tab in the Project Manager.
Options for selection (CTRL Q to select – other options go to tools select Query options):
to create a box selection, click and drag
to create a circle, hold down the C key and click and drag
to create a linear selection, hold down the CTRL key and click and drag
Now copy to the active layer, delete anything you don’t need and then save with a memorable new file name.
Alternatively copy everything to the Live Layer and use the Selection Tool to select your polygons, as above, or use the Selection Manager to create more complex queries. “Save selection” rather than whole Live layer and continue with the second half of the process.
Make a database extract
From the Utilities menu, select under the first item Make database extract for .dra and follow the steps carefully:
Select the .dra file you’ve just created
Link to the old database
Chose the link column (a unique id)
Save to a database extract with the same name as your .dra
If all is well, you can now edit your .dbf file and edit or export to some other format.
Now that we have a database, certain query options become available. Before you can query the database, with the data tool, you need to check that the database is hit-able. To check this option, go the layer submenu and you can click make hit-able, or do the same in the database subtab in the Project Manager.
Now when you click a polygon you’ll get a simple pop up of the underlying information as it relates to the selected feature.
Also in the project manager, note the Link Column. In most cases it will be the first column or ID.
The On Hit tab has an option to make the database Read Only, including a variety of other useful options that will be explained later.
It is possible now to edit the database in Excel, remembering only that each row MUST correspond to an id in our polygon file. However we can add further columns, remembering here that all we need to do is to add a descriptive title.
There is an option, within Map Maker itself, to add rows and columns, provide a column heading or title, set the default format, move columns to the left or the right and rows up and down. Advanced options are available here too.
You can add data on a per record basis, but remember that the built in tools can give a number errors. Adding columns can shunt data around unpredictably, so always it carefully or preferably stick to Excel.
Now when we use the query tool, you can see the new column Description is viewable.
Although we’ve covered this before, it is worth dwelling on how this works in a bit more detail.
If you are editing data or creating new data, you can create basic labels as you go OR you can add or refine them later. If you want to modiy a saved layer, remember that you will have to copy it to the Live Layer.
Using the simple Edit functions (the CTRL+E key combination) and clicking on the polygon or feature, selecting the Basics tab allows you to modify the polygon’s Label or modify it’s ID.
Until such time as we create an associated database, there will not be scope to add additional information in the form of attributes tour simple data.
To create a database, we use the Utilities menu to generate columns from .dra file. The diagram shows that we can select at any number of columns to associate from the .dra file – except the ID is the only obligatory one. At this point, there is no link to the database, we have simply created a database based on the .dra file, which can be different from the one displayed on screen. The database is saved as a .dbf file and can be read by a number of spreadsheet programs.
So the next job is to link the database to the .dra file and save this all as a project.
The linking is performed through the project manager. The link tab is next to the style tab. Simply choose the database you’ve just created.
Now, when we go to edit a polygon (in Live Layer), you’ll see that a new Data tab appears alongside the Basics, Style and Actions, which has automatically created a number of fields, provided you selected them.
When you save your .dra file, you should also be prompted to save the database file. It is usually safe to overwrite the existing one, unless you have performed a large number of changes. If you experience any issues you should save everything (.dra and .dbf) with a new name.