The subtype field must always be an integer, and the material field is set as text. This entry can be changed easily with an eraser.
5.On the Tables worksheet, erase the field type for Material and enter SI. Also, add the name Sewer_Line_Material in the Subtype column on the right with an (S1) notation.
Next, you can fill in the Subtypes worksheet for the first material, polyvinyl chloride (PVC). The default value for PipeSize will be 8 inches, and the domain designed previously should be applied to this field. The default for the description field will be Oleander. And to save a little typing, make the default for Year_Built 2010. You can change it once a year to keep up with new construction.
6.On the Subtypes worksheet, write the name of the Subtype field, Sewer_Line_Material. Write the code as 1 and the description as PVC. In the Field column, write the name Pipe_Size, note its domain as Sewer_Pipe_Size, and its default value as 8.
Note that the default value does not have the inch marks next to it. Remember that its field type is short integer, so the value entered in the database must be short integer. But the inch mark is stored in the domain description, which can be used for labeling later if necessary. The benefit here is that you can do math processes on the pipe size value, such as a selection PipeSize ≤ 8, but still have the value with an inch mark for labeling.
7.Continuing on the Subtypes worksheet, write the names of the other fields and their default values. For the Description field, write a default value of Oleander. For the Year_Built field, write a default value of 2019.
This work completes the design for the first choice of subtype. The next choice will be for the material type of high-density polyethylene (HDPE). The default size will be 10 inches, and the defaults for description and year built will be the same as before.
8.On the next blank line of the Subtypes worksheet, write the code of 2 with a description of HDPE. In the Field column, write the name Pipe_Size, note its domain as Sewer_Pipe_Size, and its default value as 10. As before, write a default value of Oleander for the Description field and 2019 as the default value for the Year_Built field.
YOUR TURN
Fill in the information for a third subtype code with the material type ductile iron, or DI. It will have a default size of 12 inches with the same domain as the other sizes, as well as a default description of Oleander and default year built of 2019.
There are two more material types, and although they are no longer installed new, they could cause validation problems later if they are not included in the design. The two types are concrete and clay. You’ll add them as choices 4 and 5 on the Subtypes worksheet. They will require no domains or defaults because they will not be used to enter new pipes.
9.On the next blank line, write a code 4 with a description of Conc and a code 5 with a description of Clay. No defaults or domains are required for these subtypes.
This work completes the design for linear features. Next will be investigating the point features associated with the sewer lines. At each intersection of sewer lines, and at various locations along their length, manholes are constructed for maintenance. At the ends of the lines, a smaller access port called a cleanout is added to accommodate the mechanical device that is run down the pipes to clean out clogs. The cleanouts will be represented in the geodatabase by points, with certain attributes associated with them.
These points have a behavior relationship with the lines, in that they must fall on top of the lines. If any networking is done, the points must be snapped to the lines to preserve connectivity. They must also reside in the same feature dataset.
The data associated with the points will include several fields. The first will be a code that marks which points are manholes and which are cleanouts. Other information such as the flow line, rim elevation, and depth (rim elevation minus the flow line elevation) will be copied from the construction documents. Finally, a field for the year of construction and another for description (ownership) will be needed.
10.On the geodatabase design form, write the name of the new point feature class as SewerFixtures. Give it a feature class type of PNT (Point) and a description of Sewer Fixtures.
Next, add the fields for the point feature class on the Tables worksheet.
11.On the Tables worksheet, write the name of the new feature class, and add the following field names with their field types, aliases, and null value allowances:
•Fix_Type, Fixture Type, SI, No
•Flowline, Flowline Elevation, Float, Yes
•Rim_Elev, Rim Elevation, Float, Yes
•Depth, Depth from Surface, Float, Yes
•Year_Built, Year Built, LI, Yes
•Description, Owner, Text, No
Even though there won’t be defaults or domains for any of these fields, it might be useful to make fixture type a subtype. One benefit of subtypes is that each code in the subtype list can be selected as a target when editing. Without a subtype, you would set the target as SewerFixtures and click to add a point. Then you would have to set the fixture type immediately because it cannot be null. With a subtype set for fixture, the target drop-down list would show the two types of fixtures allowed. As each new point is entered, the fixture type field is automatically populated, meaning that it can never be null. For the short amount of time it takes to set up the subtype structure, it would be a great way to enforce the data integrity rule of not allowing null values. At the same time, a default for description and year built could be added for convenience. You’ll start by noting the subtype name on the tables form, and then populate the subtype form.
12.On the Tables worksheet, write the subtype name Sewer_Fix_Type for the Fix_Type field with a notation of (S2). Under SewerFixtures, for the following fields, add a default Year Built value of 2019 and a default Description value of Oleander.
13.On the Subtypes worksheet, write the name of the subtype as Sewer_Fix_Type. Give it a code 1 for Manhole and a code 2 for Cleanout.
The interceptors will also have associated fixtures, but they are all manholes. This factor makes for a simple feature class because all the features will be symbolized the same. They will have the same fields as the Oleander fixtures, except for fixture type and description. These fields are unnecessary because their values would always be the same.
14.Add a new feature class to the Geodatabase worksheet (page 1). Name it InterceptorFix, with a feature type of PNT and a description of Interceptor Fixtures.
15.Fill in the Tables worksheet for the new feature class InterceptorFix with these fields and values:
•Flowline, Flowline Elevation, Float, Yes
•Rim_Elev, Rim Elevation, Float, Yes
•Depth, Depth from Surface, Float, Yes
•Year_Built, Year Built, LI, Yes (default value of 2019)
The geodatabase design forms make this design seem simple, but it is a fairly complex database. A good deal of thought was put into the fields required for the feature classes, the relationships of the feature classes, and the inclusion of data integrity rules, such as defaults, domains, and subtypes.
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