ArcGIS Explorer Component Help |
ColumnCollection..::.ObjectIDColumnName Property |
ColumnCollection Class Example See Also |
Gets the name of the column which is responsible for managing the unique identity of a Row.
Namespace:
ESRI.ArcGISExplorer.DataAssembly: ESRI.ArcGISExplorer (in ESRI.ArcGISExplorer.dll) Version: 2.0.0.1500 (2.0.0.1500)
Syntax
C# |
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public string ObjectIDColumnName { get; } |
Visual Basic (Declaration) |
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Public ReadOnly Property ObjectIDColumnName As String |
Field Value
The name of the geodatabase-managed unique identifier column. Typically this is the OBJECTID column for geodatabase tables/feature classes, the FID column for shapefiles and OID column for dBase tables.Remarks
Although the unique identifier column name in ArcSDE feature classes and tables is usually called OBJECTID,
it is also possible that another column has been registered to perform this function.
Examples
The code below provides a number of examples for working with ColumnCollection and Column properties.
The second example uses the ObjectIDColumnName property to return the unique identifier column by name.
CopyC#
//Open the Regions feature class stored in the Scotland file geodatabase Geodatabase gdb = new Geodatabase(@"C:\Data\Scotland.gdb"); Table regionsTable = gdb.OpenTable("regions"); //Example 1 - column properties for the non-spatial, "Region" Column Column regionColumn = regionsTable.Columns["Region"]; System.Diagnostics.Debug.Print(regionColumn.Name); //Prints "Region" System.Diagnostics.Debug.Print(regionColumn.AliasName); //Prints "Region" System.Diagnostics.Debug.Print(regionColumn.Type.ToString()); //Prints "String" System.Diagnostics.Debug.Print(regionColumn.Length.ToString()); //Prints "50" //Check that the parent data container is a geodatabase as the IsNullable and Required column //properties only apply to this data format if (regionsTable.Parent is Geodatabase) { System.Diagnostics.Debug.Print(regionColumn.IsNullable.ToString()); //Prints "True" System.Diagnostics.Debug.Print(regionColumn.Required.ToString()); //Prints "False" } //Example 2 - column properties for the non-spatial, "ObjectID" column //Check that the Regions table has a unique identifier column if (regionsTable.Columns.HasObjectIDColumn) { //Get the unique identifier column Column oidColumn = regionsTable.Columns[regionsTable.Columns.ObjectIDColumnName]; System.Diagnostics.Debug.Print(oidColumn.Name); //Prints "OBJECTID" System.Diagnostics.Debug.Print(oidColumn.Required.ToString()); //Prints "True" System.Diagnostics.Debug.Print(oidColumn.IsNullable.ToString()); //Prints "False" } //Example 3 - column properties for the spatial, "Shape" column //Check that the Regions table can contain vector data if (regionsTable.IsSpatial) { //Get the column that can store geometry Column shapeColumn = regionsTable.Columns[regionsTable.Columns.SpatialColumnName]; System.Diagnostics.Debug.Print(shapeColumn.Name); //Prints "Shape" System.Diagnostics.Debug.Print(shapeColumn.CoordinateSystem.Name); //Prints "British_National_Grid" System.Diagnostics.Debug.Print(shapeColumn.HasZ.ToString()); //Prints "False" //check that this table can store Polygon geometries if (shapeColumn.GeometryType == GeometryType.Polygon) { //Get the column which stores the perimeter length of each geometry Column lengthCol = regionsTable.Columns[regionsTable.Columns.LengthColumnName]; System.Diagnostics.Debug.Print(lengthCol.Name); //Prints "Shape_Length" //Gets the column which stores the area of each geometry Column areaCol = regionsTable.Columns[regionsTable.Columns.AreaColumnName]; System.Diagnostics.Debug.Print(areaCol.Name); //Prints "Shape_Area" } }
CopyVB.NET
'Open regions feature class stored in the Scotland file geodatabase Dim gdb As Geodatabase = New Geodatabase("C:\Data\Scotland.gdb") Dim regionsTable As Table = gdb.OpenTable("regions") 'Example 1 - column properties for the non-spatial "Region" Column Dim regionColumn As Column = regionsTable.Columns.Item("Region") System.Diagnostics.Debug.Print(regionColumn.Name) 'Prints "Region" System.Diagnostics.Debug.Print(regionColumn.AliasName) 'Prints "Region" System.Diagnostics.Debug.Print(regionColumn.Type.ToString()) 'Prints "String" System.Diagnostics.Debug.Print(regionColumn.Length.ToString()) 'Prints "50" 'Check that the parent data container is a geodatabase as the IsNullable and Required column 'properties only apply to this data format If TypeOf regionsTable.Parent Is Geodatabase Then System.Diagnostics.Debug.Print(regionColumn.IsNullable.ToString()) 'Prints "True" System.Diagnostics.Debug.Print(regionColumn.Required.ToString()) 'Prints "False" End If 'Example 2 - column properties for the non-spatial, "ObjectID" column 'check that the Regions table has a unique identifier column If (regionsTable.Columns.HasObjectIDColumn) Then 'Get the unique identifier column Dim oidColumn As Column = regionsTable.Columns.Item(regionsTable.Columns.ObjectIDColumnName) System.Diagnostics.Debug.Print(oidColumn.Name) 'Prints "OBJECTID" System.Diagnostics.Debug.Print(oidColumn.Required.ToString()) 'Prints "True" System.Diagnostics.Debug.Print(oidColumn.IsNullable.ToString()) 'Prints "False" End If 'Example 3 - column properties for the spatial, "Shape" column 'check that the Regions table can contain vector data If regionsTable.IsSpatial Then 'Get the column that can store geometry Dim shapeColumn As Column = regionsTable.Columns.Item(regionsTable.Columns.SpatialColumnName) System.Diagnostics.Debug.Print(shapeColumn.Name) 'Prints "Shape" System.Diagnostics.Debug.Print(shapeColumn.CoordinateSystem.Name) 'Prints "British_National_Grid" System.Diagnostics.Debug.Print(shapeColumn.HasZ.ToString()) 'Prints "False" 'check that this table can store Polygon geometries If shapeColumn.GeometryType = GeometryType.Polygon Then 'Get the column which stores the perimeter length of each geometry Dim lengthCol As Column = regionsTable.Columns.Item(regionsTable.Columns.LengthColumnName) System.Diagnostics.Debug.Print(lengthCol.Name) 'Prints "Shape_Length" 'Gets the column which stores the area of each geometry Dim areaCol As Column = regionsTable.Columns.Item(regionsTable.Columns.AreaColumnName) System.Diagnostics.Debug.Print(areaCol.Name) 'Prints "Shape_Area" End If End If