DataBase Mask Field
Several options, including some map queries, use a MASK field in the database. This can be set the "Y" or "N" and the database filtered based on the result.
These options will create the MASK field if it does not exist.
You can create the multiple MASK fields when you Merge shapefiles. The Database options tab on the options form controls whether the mask, or multiple mask fields, will be added. You can merge a single shape file, to create a duplicate, which can add the MASK field(s).
You can also add a MASK field on the EDIT menu of the database table form.
If you have multiple MASK fields (they will be MASK, MASK2, MASK3, MASK4, and MASK5, you will be asked which to use when you create a map query. You can use these to create complex geometric filters with AND or OR logic.
After you do a Filter or Map query option, you can click on the "MASK" field and use the Fill Field command to put a "Y" or "N" for all selected records.
Last revision 4/30/2009