NR 322: Editing Attributes Jim Graham Fall 2008 Chapter 6

Selection Selection tab on TOC Manual Selection Select by Attributes Select by Location Right click on layer -> Selection -> Create Layer From Selected Features

Editing Attributes 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 Adding and deleting features adds and deletes rows

Adding Fields Make sure the Shapefile is not marked as Read-Only Make not in an edit session Select “Add Field” from the Options menu Name the field Select the type of data

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

Name the Field Arc Limits column names to 10 characters Remember you’ll be using these in calculations and queries!

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”

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 digts) –Long Integer: 32-bit integer (9 digits) –Float: 32-bit floating point (real) –Double: 64-bit floating point (real) –Text: up to 254 characters –Date: MM/DD/YYYY format

Editing Attributes 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

Spatial Attributes FID – ESRI’s internal identifier Shape – Actual spatial data

Joins FIDShape Name State_FIPS 0PolygonLarimer08 1PolygonJackson08 2PolygonButte06 3PolygonSacramento06 FIDShapeNameState_FIPS 0PolygonColorado08 1PolygonColorado08 2PolygonCalifornia06 3PolygonCalifornia06 Counties_US States

After Join Counties_U S.FID Counts_US.Shape Counites_US.Name States.Name 0PolygonLarimerColorado 1PolygonJacksonColorado 2PolygonButteCalifornia 3PolygonSacramentoCalfiornia

Wildlife Data