1. Attributes in ArcGIS

2. ArcGIS Attributes FID – ESRI’s internal identifier Shape – Actual spatial data

3. Adding Fields Make sure the Shapefile is not marked as Read-Only Make sure you’re not in an edit session Select “Add Field” from the Options menu Name the field Select the type of data Careful with “Precision”

4. Checking the Shapefile Use the “File Explorer” or “My Computer” Select all the files for the Shapefile by: –Shift-clicking each file –Drag the cursor over all of them Right click on one of the selected files If “Read-only” is checked: –Uncheck it –Click “OK”

5. Checking the edit session Right click on the menu bar Select “Editor” If “Start Editing” is grayed out: –Select “Stop Editing”

6. Adding Fields

7. Naming Fields Arc only allows 10 characters Remember you’ll be using the Name in calculations and queries!

8. Select the Field Properties If you change the precision or scale: –Arc map may change the type for you! Types: –Short Integer: 16-bit integer (5 digits) –Long Integer: 32-bit integer (9 digits) –Float: 32-bit floating point –Double: 64-bit floating point –Text: up to 254 characters –Date: MM/DD/YYYY format

9. Precision can change “Type” ArcGIS will change the “Type” if you put in a precision that is beyond the specified type

10. Delete a Field Must be outside an edit session

11. Editing Attribute Values The attribute “table” contains rows and columns similar to a spreadsheet However, it’s history and future are based on databases: –Columns=Fields –Rows=Records We can add and delete columns (fields) Adding and deleting features adds and deletes rows

12. Calculate Geometry

13. Editing Attribute Values If attributes won’t change: –Make sure you’re in an edit session Double click on the cell to type in a new value Use the “Field Calculator” to change entire columns

14. Start Editing

15. Starting an Edit Session Without an Edit Session – ArcGIS will not track your changes so “Undo” will not work!

16. Making Changes Click (or double-click) in the cell Type changes – easy! –Dates are in MM/DD/YYYY format

17. Stop Editing! If you don’t select “Stop Editing”, your changes will not be saved

18. Coordinate Attributes It is common to see Lat/Lon or Easting/Northing in attribute tables for point layers These are not the values used to render the spatial data! These values are not updated when you project, edit, or transform the spatial data! To update these columns…

19. Selection Selection tab on TOC Manual Selection –Click to select –Shift-click to add/remove from selection Select by Attributes Select by Location Right click on layer -> Selection -> Create Layer From Selected Features –Then, “Export” the data to a new file

20. Select by Attributes

23. SELECT * FROM TableName WHERE: –“WHERE Clause” or Filters