If you already have a table that describes the relationship between both sides of a many to many relationship, it would be nice to be able to load this into a geodatabase table. The following code attempts to do just that and requires that the temporary input table already be in the same file geodatabase that contains the related tables and the relationship class (must be pre-defined).
This seems to be harder than it needs to be as there should be a tool in the interface to do this. There is no 'Load' on the intermediate table's (a.k.a. m to n relationship class) context menu in ArcCatalog. Also the ArcToolBox Table to Relationship Class didn't seem to work. Hence the code below.
Another note. If you want the intermediate table to carry some attributes in a geodatabase, keep in mind that fields in the intermediate table can't utilize geodatabase domains. This is documented by ESRI in the ArcMap and ArcObjects help but seems like an unnecessary shortcoming.
Public Sub validateAndLoadMNRelationshipToGDBIntermediateTable()
Dim pFGDB_WSF As IWorkspaceFactory Dim pFeatureWorkspace As IFeatureWorkspace Dim pWorkspaceEdit As IWorkspaceEdit Dim pTempInputIntermediateTable As ITable Dim pRelationshipClass As IRelationshipClass Dim pOriginTable As ITable Dim pDestinationTable As ITable
Set pFGDB_WSF = New FileGDBWorkspaceFactory Set pFeatureWorkspace = pFGDB_WSF.OpenFromFile("D:\ZipInfo.gdb", 0) Set pWorkspaceEdit = pFeatureWorkspace
Set pTempInputIntermediateTable = pFeatureWorkspace.OpenTable("Input_MtoN_Table")
Set pRelationshipClass = pFeatureWorkspace.OpenRelationshipClass("ZipcodeToPlacename") Set pOriginTable = pRelationshipClass.OriginClass Set pDestinationTable = pRelationshipClass.DestinationClass
Dim pRelCursor As ICursor Dim pRelRow As IRow Dim pOriginCursor As ICursor Dim pDestinationCursor As ICursor Dim pOriginQF As IQueryFilter Dim pDestQF As IQueryFilter Dim pOriginRow As IRow Dim pDestinationRow As IRow Dim pRelationship As IRelationship
Set pOriginQF = New QueryFilter Set pDestQF = New QueryFilter
Set pRelCursor = pTempInputIntermediateTable.Search(Nothing, True) Set pRelRow = pRelCursor.NextRow
Set pOriginCursor = pOriginTable.Search(pOriginQF, True) Set pDestinationCursor = pDestinationTable.Search(pDestQF, True)
Set pOriginRow = pOriginCursor.NextRow Set pDestinationRow = pDestinationCursor.NextRow
Set pWorkspaceEdit = pFeatureWorkspace
If Not (pOriginRow Is Nothing Or pDestinationRow Is Nothing) Then Set pRelationship = pRelationshipClass.CreateRelationship(pOriginRow, pDestinationRow) End If
