Before we start creating the geodatabase, we need to design a template that includes the tables, fields, and data types for the Bestaurants project. This template is called the geodatabase schema.

So, let's design the logical schema for the Bestaurants project. We will start with a very simple design where we create the basic atom dataset in the geodatabase, the feature class.

According to the case study, we need to create a geodatabase that accommodates diners, cafes, restaurants, bars, and lounges. So, we can create each one of them in a separate feature class, and then we need to give appropriate fields for each feature class. Take a few moments to answer these questions: what feature classes will you include in the geodatabase? What attributes will you use for each class? What are the data types for these attributes? Take a look at the following table:

There are a lot of ways to design the schema for a geodatabase. There are really good ways that keep your geodatabase healthy in the long run, and there are bad ways that are inefficient. This design is a simple one; it is not the ultimate, and you might come up with a better design. The only reason I selected this is for its simplicity, and there is definitely plenty of room for improvement. You will learn how to create an efficient schema design in Chapter 3, Modeling Geodatabases, as you are introduced to more geodatabase datasets.

As you can see, we have merged the bars and lounges into one single feature class. We have used point geometry to represent these feature classes since it is easier to sketch, which could be identified with a Global Positioning System (GPS) device. These feature classes are also fast to draw, and we don't really care about the boundaries. However, it all depends on your requirements; whether it is necessary to identify the boundary of a certain feature or not. You may use polygon geometry if you want to.

After we have designed the geodatabase schema, it is now time to author the geodatabase. In this section, we will use ArcCatalog to create the geodatabase. ArcCatalog is an application that allows us to author geodatabases, browse through them, add/delete datasets from geodatabases, and so on. To create your first geodatabase, perform the following steps:

This will create a file geodatabase in the specified folder with a default name of New File Geodatabase.gdb; rename the new geodatabase to Bestaurants. The gdb extension is automatically appended.

Creating the feature classes

In the previous section, we designed the logical schema for our geodatabase. We will now create the actual datasets, or the physical schema. First, we start by creating the feature classes as follows:

1. Open ArcCatalog and browse to your Bestaurants geodatabase in the Catalog Tree window.
2. Click on the Bestaurants file geodatabase, right-click on the empty right panel, point the cursor to New, and then click on Feature Class…, as shown in the following screenshot:
   

   This will open up the New Feature Class dialog where you specify the basic properties of the feature class. In the Name field, type Diners. This is the physical name of the feature class in the geodatabase, and it should not contain special characters and should not include any spaces.

3. Type Belize Diners in the Alias field. This is a description of the feature class's name. It can be anything you want. When you add a new layer, it takes this alias name by default.
4. In the Type drop-down list, select Point Features to create the feature class with point geometry.

   The Geometry Properties section offers advanced options to enable the feature class. This includes the M value that helps in the route information for linear features and the Z value that is used for 3D representation, which enables the elevation and extrusion of features. The Z value can be useful, for example, if a restaurant is located on the 11th floor of the Ritz Carlton hotel.

   Note

   Besides X and Y coordinates, the M value can be added to each vertex on a line to provide more information, such as the direction.

   Unlike X and Y coordinates, the Z value can be considered as the height of a feature upward or downwards. This value can be assigned to features so they are represented in a 3D plane.

5. Since we don't need to store route or 3D data at this stage, leave the M and Z values unchecked. Click on Next. This is illustrated in the following screenshot:
   

   In the next dialog box, you will set the spatial reference for our new feature class. You will use the WGS_1984_Web_Mercator standard spatial reference, which is also used by Google Maps.

6. In the spatial reference drop-down list, select WGS_1984_Web_Mercator and press Enter to find its item.
7. Expand the Projected Coordinate Systems node, then expand the World node, and then click on the WGS 1984 Web_Mercator (auxiliary sphere) node, as illustrated in the following screenshot.
   
8. Click on Next to move to the next form.

   Next, we set the XY Tolerance value for the feature class. As you start adding features, you might want to add some features close to each other, but you don't want them to snap into the same position. In this case, make this value smaller to get a higher accuracy for each feature position. However, sometimes, you will need to add features on top of each other, making them overlap on purpose, especially if you have Z values. Too small a tolerance value might make it difficult to snap these features into a single location and might cause problems with shared boundaries.

9. As you can see, this value needs to be carefully planned, but for now, leave the XY Tolerance value to its default value, which is 0.001 meters, and click on Next.

   Note

   The XY Tolerance value is the minimum distance after which two features will snap together.

In the next form, we select the configuration keyword; choose the Default configuration keyword and click on Next.

Note

The configuration keyword is a table space in which feature classes and tables are stored. Each configuration has certain properties, such as the geometry type and file size, which are shared by all objects in that keyword.

Finally, we add the fields for our feature class. Note that two fields are already added for you. The first field is OBJECTID, which is also the primary key; a sequence number that represents each feature in the feature class uniquely.

Note

The primary key is a column by which a record is uniquely identified in a table or a dataset.

The second field is SHAPE, which if you remember, we have added by specifying the geometry type. So, we need to add three more fields: NAME, WEBSITE, and RATING; click on an empty row in the Field Name column and add the following fields:

Name	Data Type
NAME	Text
WEBSITE	Text
RATING	Short Integer

After adding all the fields, your dialog box should look like the following screenshot; click on Finish to create the feature class:

You just created your first feature class; if you take a look at the icon, you will see three small dots, which indicates that this feature class has a point geometry.

Using the same approach, create the rest of the feature classes, Cafes, Restaurants, and Bars_and_Lounges, in your geodatabase based on the schema we designed earlier.

Note

If you are creating multiple feature classes with similar fields, use the Import... feature in the fields' page to import the fields from an existing feature class. This could prove efficient when you are authoring your geodatabase.

After creating all the feature classes, your final geodatabase should look like the following screenshot:

We have authored our Bestaurants geodatabase and created the food and drinks venues' feature classes. However, these classes are empty, and until they have some features, we can't visualize them; it is time to populate them with features. To do that, we need an editing tool, and ArcMap can help with this. However, before we can start editing our geodatabase, we need to know where we can add these features. We can't just place them anywhere in the world. We need a reference to base our editing on, Basemap. I have already prepared a map document and saved it to the extent of Belize. You can find it in the supporting files for this chapter, 8648OT_01_Files, which can be downloaded from www.packtpub.com.

Browse to 8648OT_01_Files\MapDocuments and open the Belize_BaseMap.mxd file; this will open ArcMap. You will need an Internet connection for this exercise since the document connects to an online basemap. We will start by adding the Restaurants feature class. To do this, perform the following steps:

Notice that a new layer is added with the alias name of the feature class that we specified while creating it. Also, a default red point is added as a symbology for our feature class. Let's change it to a more relevant symbol by performing the following steps:

Now, it is time to add some features. Before we do so, make sure that you close ArcCatalog and that you do not have any connections to your geodatabase. Now, to display the Editor toolbar, perform the following steps:

In this chapter, you learned how to design, author, test, and edit a complete geodatabase by following a real-life example. You started with designing the schema of the geodatabase. You also specified the fields, data types, and geometry type for the feature classes. You then created the physical file geodatabase using ArcCatalog, specified the spatial reference, and used the editing tools in ArcMap to populate the geodatabase with features.

In the next chapter, you will enhance the skills acquired in this chapter to do more work with geodatabase datasets.