working with CHGIS data in MapInfo

How to open MapInfo tables

How to search GIS files

How to export attributes to tables

How to join tables to existing GIS tables

How to create thematic maps based on attributes

How to Open MI Tables

How to Search

To search for a keyword or value in MapInfo Tables use a SQL query, found in the QUERY | SELECT menu.

How to Export
If you want to export an entire MapInfo Table or a selection of one, including spatial data use FILE | SAVE COPY AS
  • Open a TABLE in MapInfo
  • open a MAP WINDOW for the table or selection you want to save
  • select SAVE COPY AS from the FILE menu
  • select the name of the TABLE or SELECTION in the dialog box that you want to save
  • hit the SAVE AS button
  • navigate to the directory in the "Save In" box where you want the new table to be saved
  • enter the name of the new export file in the "File name" box
  • choose the export table format
  • NOTE: you may select the PROJECTION you want to save the new table in...very useful for changing a projection! Otherwise don't touch this...
  • hit the SAVE button

If you want to export the attributes for an entire MapInfo Table or a selection of one, NOT including spatial data use TABLE | EXPORT

  • Open a TABLE in MapInfo
  • open a BROWSER WINDOW for the table you want to export attributes from
  • select EXPORT from the TABLE menu
  • select the name of the TABLE or SELECTION in the dialog box that you want to export
  • hit the EXPORT button
  • navigate to the directory in the "Save In" box where you want the new table to be exported
  • enter the name of the new export file in the "File name" box
  • choose the export table format
  • hit the SAVE button
  • MapInfo 6.x users exporting Delimited ASCII text will see a dialog box where one can select the "File Character Set" encoding...be sure to choose the NO CHARACTER SET CONVERSION at the bottom of the list, which preserves double-byte characters perfectly!)
  • hit the OK button
How to JOIN

If you want to join your own attribute values to an existing MapInfo Table or a selection of one, first export the ATTRIBUTES following the steps outlined in the EXPORT section above. Follow the same guidelines in preparing your new table as written in the ArcView section above. Once you have the new data table, use the QUERY | SQL SELECT to join it with the existin MapInfo Table as described below.
  • Open both the existing TABLE and the new TABLE to be joined in MapInfo
  • select SQL SELECT from the QUERY menu
  • leave the star * in the "Select Columns" box to preserve ALL the FIELDS in BOTH TABLES
  • place the cursor in the "From Tables" box
  • select the name of the TABLE or SELECTIONs that you want to save from the TABLES list on the upper right, separating each table name with a comma and a blank space, for example: TableOne, NewData
  • place the cursor in the "where condition" box
  • select the FIELD name containing the unique id # to be joined on from the first table from the COLUMNS drop-down list on the right
  • enter a blank space, an equals sign =, and another blank space
  • select the FIELD name containing the unique id # to be joined on from the second table from the COLUMNS drop-down list on the right
  • the entry in the "where condition" box should look like: TableOne.unique_id = NewData.unique_id
  • place the cursor in the "Into Table Named" box
  • enter a name for the newly joined table
  • enter the name of the new export file in the "File name" box
  • hit the OK button
Thematic Maps

If you want to create a thematic (chloropleth) map of polygons, lines or points, using a range of colors to represent different values in the attributes table of a Mapinfo Table, use MAP | CREATE THEMATIC MAP. Note: you must first join the table containing numeric values in a specific field to the MapInfo table that you want to represent as a chloropleth map, as described in the JOIN section above.
  • Open MapInfo Table
  • select CREATE THEMATIC MAP from the MAP menu
  • step one: chose a TYPE of thematic map from the column of seven buttons on the left
  • step one: choose one of the TEMPLATES available for that TYPE from the list in the center of the dialog box
  • a preview of the output is shown on the right
  • hit NEXT button
  • step two: choose the filename of the MapInfo table to be mapped from the drop-down list in the "Table" box
  • step two: choose the Field containing values to be mapped from the drop-down list in the "Field" box
  • step two: check off "Ignore Zeroes" if you want to skip over zero or null values in the selected field
  • hit NEXT button
  • step three: to change the statistical method from Natural Breaks to Quintiles, Equal Intervals, or other method, and to choose the NUMBER of gradation levels, hit the Customize: RANGES button
  • step three: to change the color values, hit the Customize: STYLES button
  • step three: to change the title, font and appearance of the legend that accompanies the thematic map, hit the Customize: LEGEND button
  • when you have made all the customize selections, hit the OK button
  • NOTE: the results of thematic maps are often misleading due to the calculation of raw values without taking into account the AREA or the DISTRIBUTION of those values across the total area occupied by a polygon feature in GIS. Those wishing to pursue thematic mapping are strongly advised to first read the following books:
    "How to Lie With Maps" by Mark Monmonier
    "How to Lie With Statistics" by Darrell Huff
    "Mapping Information" Howard T. Fisher