Pitney Bowes MapInfo Professional - Manual (Page 130)

Working with MapInfo Tables
After you have brought your data into MapInfo and created .tab files, you can manage them within
MapInfo Professional. You can view any database table in MapInfo Professional, once you have converted
it to MapInfo format. Additionally you can add or remove fields, change the order, name, type, width, or
index of any field. You can also specify or determine the projection of the table from this dialog box. You
can also check if the table is mappable (contains map objects). To make these types of changes, see
Editing a Table's Structure .
Keep in mind that you can only view the structure of a spreadsheet or database file that you convert into
MapInfo Professional's table structure. See
How Do I Get My Data on the Map? for these instructions.
To view the structure of a table, on the Table menu, point to Maintenance and click Table Structure.
The View/Modify Table Structure dialog box displays.
For more information, see Accessing StreetPro Data in the Help System.
Adding to a Table
One important operation in maintaining tables is the ability to update the data contained in the table.
MapInfo Professional's Update Column feature allows you to:
• Add a temporary column or update an existing column with data from another table
• Update a table
• Place graphic information into visible columns
Updating Information in a Subset of a Table
Use Update Column to update information in a subset of a table. For example, you could marquee the
southeast of the United States, then use Update Column to set the "sales rep" field to the name of your
sales representative for the Selection table.
You can update all the rows in a table or a selection of rows. To update a selection of rows you need to
select the rows using Select, SQL Select, the Select tool, the Boundary Select tool, or the Radius
Select tool, and then update the selection.
Adding a Temporary Column using Update Column
If you need to bring data from one table into another, you can use the Update Column command in
MapInfo Professional. In fact to bring this data into the table, you can either add a temporary column or
you can update an existing column. In both cases, use the Table menu to click Update Column to bring
over the information.
You have tremendous flexibility with how information is imported and what information is transferred.
You can perform aggregate functions to transfer averages, minima, maxima, sums, weighted averages,
and proportional sums. You can also create expressions to derive additional information from the data.
• For specific instructions and an example, see Adding a Temporary Column using Update Column in
the Help System.
Geographic and Descriptive Joins
A join allows you to join two tables. To do this, MapInfo Professional must know how to associate records
in the two tables.
For example, assume you are shading STATES by the values in SALES. Obviously, you want all
Pennsylvania sales to be associated with Pennsylvania, all Maryland sales to be associated with Maryland,
etc. MapInfo Professional has two ways of doing this:
1. From a common descriptive field.
2. Geographically/graphically.
MapInfo Professional 12.5 130
Working with MapInfo Tables