1. Assignment 3. Creating a personal geodatabase. Review Gorr/Kurland, “GIS
Tutorial 4 Geodatabases.” I. Definitions: ▫ Feature class: a group of points, lines, ...
Assignment 3. Creating a personal geodatabase Review Gorr/Kurland, “GIS Tutorial 4 Geodatabases.” I Definitions: § Feature class: a group of points, lines, or polygons representing geographic objects of the same kind (e.g., counties, buildings, roads). § Geodatabase: a set of features classes. It has the advantage of being able to store multiple feature classes and to store labels as annotation, and it can create domains for attributes (i.e. valid values or ranges of values for an attribute field) to restrict data entry to valid values. o Geodatabase allows you to incorporate feature classes (including coverages), tables, and rasters. II §
In ArcCatalog, create a personal geodatabase & import feature classes (or coverages): o Right-click your data folder>New>Personal Geodatabase (type an appropriate name)>Enter. o Right-click the new geodatabase>Import>Feature Class (single). § In the tree, click on an appropriate feature class (or coverage) & drag it to the Input Features box of the dialog. Check that the output path is correctly specified. § In the Output Feature Class Name box, type an appropriate name. OK. § When the operation is completed, click Close. § Check or, if necessary, specify a feature class or coverage’s geographic projection. • Within the geodatabase, right-click the feature class>Properties>click gray area to left of ‘Shape’>click Ellipsis button next to ‘Unknown’ value>select, import, or create an appropriate coordinate system. OK. • In ArcCatalog, double-click the personal geodatabase to see the new feature class (perhaps also clicking View>Refresh). § Right-click the new geodatabase>Import>Table (single). o
Follow the same procedure presented above. § Right-click the new geodatabase>Import>Feature Class (multiple). § This time, click & drag two or more appropriate feature classes into the Input Features box of the dialog. Check that the output path is correctly specified. § When the operation is completed, click Close. § In ArcCatalog, double-click the personal geodatabase to see the new feature classes (perhaps also clicking View>Refresh).
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Note: you can save from ArcMap to a geodatabase by selecting the geodatabase option in the ‘save’ dialog box.
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In ArcCatalog, create a new feature class as a structure into which you would eventually add data: o You will have to define the feature class geometry (point, line, or polygon; and spatial reference [i.e. coordinate system (x,y values), spatial domain (bounding coordinates) & precision (smallest measurable units)]). o Right-click your personal geodatabase>New>Feature Class. o In Name box, type an appropriate name. o Next. Next. o In the Field Name column, click ‘Shape’ (which opens the ‘Field Properties’ dialog box below). o Field Properties: for Geometry Type, click ‘Polygon’ to obtain the selection arrow. Then select the appropriate type (polygon, line, or point). o Field Properties: for Spatial Reference, click the Ellipsis button next to ‘Unknown’ value. If necessary click the Coordinate System tab. Then select, import, or create an appropriate coordinate system. OK. o Check the ArcCatalog tree (perhaps clicking View>Refresh) to see that the new feature classes appear.
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Note: In creating a geodatabase you can alternatively choose to create the structure for a ‘feature data set’ (instead of a feature class) to accommodate feature classes: New>Feature Data Set. Then you can create the structures for feature classes within the feature data set. You can also create the structure for a Table: New>Table.
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Here’s another, convenient way to save a file to a geodatabase: o When exporting a feature from ArcMap, you have the option of saving it in ArcCatalog as either a shapefile or a geodatabase. o Click the dropdown arrow to see this option.
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There also are geodatabase options for including Tables and rasters.
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See Ormsby et al., 14c, on adding fields & domains, & chapter 15 on creating features.
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