ArcObjects - Select record from table

Question

I ́ve a project in VBA but I hit a wall that I can't pass. What I want to do:

I ́ve a table (of parcels) with the fields: ID, Name, Area, Scale. For each Parcel there is a different scale!

I input, in a text box, the name of a parcel. I want to "get" the corresponding scale.

Does anybody know how I can do that?

• patrick: Do you want a QueryFilter?

Answer 1

Here is a code example of a QueryFilter. You could assign a variable to hold your text box value for this line "APP_TYP = 'PA'" and update this line indexClass = pUpdateFeatures.FindField("Dir") to point to your scale field. The result will give you a message box of the scale value.

' Par 1: Define the feature class.
 Dim pMxDoc As IMxDocument
 Dim pFeatureClass As IFeatureClass
 Dim pFeatLayer As IFeatureLayer
 'Dim pFeatureClass As IFeatureClass
 Dim pFields As IFields
 Dim ii As Integer
 Set pMxDoc = ThisDocument
 Set pFeatLayer = pMxDoc.FocusMap.Layer(0)
 Set pFeatureClass = pFeatLayer.FeatureClass
 ' Part 2: Prepare a feature cursor.
 Dim pQFilter As IQueryFilter
 Dim pUpdateFeatures As IFeatureCursor
 ' Prepare a query filter.
 Set pQFilter = New QueryFilter
 pQFilter.WhereClause = "APP_TYP = 'PA'"
 ' Create a feature cursor for updating.
 Set pUpdateFeatures = pFeatureClass.Update(pQFilter, False)
 ' Part 3: Calcuate the Class value.
 Dim indexClass As String
 Dim pFeature As IFeature
 indexClass = pUpdateFeatures.FindField("Dir")
 Set pFeature = pUpdateFeatures.NextFeature
 MsgBox ("Scale value = " & pFeature.value(indexClass))

• ujjwalesri: I dont see any need of an update cursor...isnt simple Search cursor enough for the job?

Answer 2

Try this:

Dim pMxDoc As IMxDocument
Dim pFeatureClass As IFeatureClass
Dim pFeatLayer As IFeatureLayer
Dim pFields As IFields
Dim ii As Integer
Set pMxDoc = ThisDocument
Set pFeatLayer = pMxDoc.FocusMap.Layer(0)
Set pFeatureClass = pFeatLayer.FeatureClass
' Part 2: Prepare a feature cursor.
Dim pQFilter As IQueryFilter
Dim pFeatCursor As IFeatureCursor
Dim pFeature As IFeature
' Prepare a query filter.
Set pQFilter = New QueryFilter
pQFilter.SubFields = "PARCEL_NAME, SCALE" 'Retrieve only these fields
pQFilter.WhereClause = "PARCEL_NAME='" & txtParcelName.Text & "'" ''' Text box on form
' Create a feature cursor for updating.
Set pFeatCursor = pFeatureClass.Search(pQFilter, true)
' Part 3: Get the Scale value
Do
pFeature = pFeatureCursor.NextFeature
If pFeature IsNot Nothing Then
MsgBox("Scale: " & pFeature.Value(pFeatureCursor.FindField("SCALE")))
End If
While !(pFeature = Nothing)

Answer 3

Create a select cursor. I'm not sure about VBA but for python: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//000v00000039000000.htm

#iName is input testing Name
parcels = arcpy.SearchCursor(fParcels)
for parcel in parcels:
 if parcel.Name == iName:
 scale = parcel.scale