Using ArcMap to Load APDM/PODS ESRI Spatial LineLoop Records
Posted by Tracy Thorleifson on Fri, Oct 15, 2010
In the previous post we used the ArcToolbox Append tool to load features into the APDM 5 / PODS ESRI Spatial 5 StationSeries feature class using our Raw Pipeline Routes as the data source. In this post we'll use Raw Pipeline Routes to populate the APDM 5 / PODS ESRI Spatial 5 LineLoop object class.
The LineLoop table in an APDM / PODS ESRI Spatial geodatabase does not store features. Rather, it may be thought of as a logical placeholder that collects and organizes the centerline (station series) features that comprise a pipeline system. Put in data modeling terminology, a LineLoop record may be related to one or more StationSeries features; each StationSeries feature must be associated with a LineLoop record. For those of you familiar with the PODS relational model, the LineLoop object class is roughly analogous to the PODS Line table.
LineLoop records may also be organized hierarchically via entries in the LineLoopHierarchy table. This means that the LineLoop table can be used to establish your pipeline system hierarchy; you can have as many hierarchy levels as desired. LineLoop records that relate only to other LineLoop records in the system hierarchy are referred to as logical LineLoops; LineLoop records that actually define a pipeline and relate to StationSeries features are referred to as physical LineLoops. In our example we'll load only physical LineLoop records corresponding to the pipelines in Raw Pipeline Routes.
We'll again make use of the ArcToolbox Append tool in our data loading efforts, but first a note on the limitations of the tool. The Append tool can only append from a source dataset to a target dataset of the same type. That is to say, the Append tool can append from a polyline feature class to a polyline feature class, or from an object class to an object class, but not from a polyline feature class to an object class. This poses a challenge, because Raw Pipeline Routes is a PolylineZM feature class, and LineLoop is an object class.
Our work around is to convert Raw Pipeline Routes to a query table. To do this we'll use the ArcToolbox --> Data Management Tools --> Layers and Table Views --> Make Query Table tool. (The tool is perhaps oddly named; if the query contains a shape column the output is a query layer rather than a table.) To open the Make Query Table tool in ArcMap, open the ArcToolbox window by clicking on the ArcToolbox button on the Standard toolbar, navigate to the Make Query Table tool, and double-click it:
In the Make Query Table tool window, select Raw Pipeline Routes in the Input Tables pull down; select the LineName and LineGUID fields in the Fields control; enter Raw Pipeline Routes QueryTable in the Table Name text box; select USE_KEY_FIELDS in the Key Fields Options pull down, and OBJECTID in the Key Fields control. The output query table should resemble the following:
We'll use the ArcToolbox Append tool to load the records from Raw Pipeline Routes QueryTable into the LineLoop table in our target APDM 5 geodatabase:
In the Append tool window, select Raw Pipeline Routes QueryTable in the Input Datasets pull down; select LineLoop in the Target Dataset pull down; select NO_TEST in Schema Type pull down, and apply the following field mappings in the Field Map control:
- Target Field - Source Field
- EventID - LineGUID
- OriginEventID - LineGUID
- LineName - LineName
Press the OK button in the Append tool window to load the records from our query table into the LineLoop table. Your LineLoop table should look something like this:
Perform an Identify on a LineLoop record by right-clicking on the row header in a row and selecting the Identify option from the context menu. You should be able to trace the relationship from the identified LineLoop record to its child StationSeries records:
And there you have it! LineLoop and StationSeries are now loaded, which puts us two thirds of the way to a complete APDM / PODS ESRI Spatial centerline. YAY! In the next post we'll round out the centerline loading by tackling the ControlPoint feature class.