Changing feature class and field aliases in bulk using ArcPy?

Question

I have over a hundred FCs, each with 10 or 20 attributes to add or change the aliases for, two or more times a year. Needless to say, this is not something I'm going to grunt my way through. How can I automate this process?

Python solution preferred but will use anything that works.

I have access to Arcgis 9.3.1 and 10 (ArcInfo license level).

• matt wilkie: I found the [Edit Feature Class Schema][1] v9.3 developer sample for ArcCatalog . It changes the alias for the selected feature classes into the value hard coded in the script. So not a batch process but headed in that direction. [1]: resources.esri.com/help/9.3/ArcGISDesktop/com/samples/…
• matt wilkie: related (a foundation building block): gis.stackexchange.com/questions/80/…

Answer 1

As of version 10.1 AlterAliasName() can be used to re-alias tables:

table = r"C:\path\to\connection.sde\OWNER.TABLE"
arcpy.AlterAliasName(table, "table_alias")

As of version 10.3 Alter Field can be used to re-alias fields:

table = r"C:\path\to\connection.sde\OWNER.TABLE"
arcpy.AlterField_management(table, "FIELD_NAME", new_field_alias="field_alias")

Answer 2

With help from Mark Cederholm I have a working solution using python and arcobjects. It's rough around the edges, but it got the job done. After following the recipe on that page, create a new script which uses the GetLibPath, NewObj, CType, OpenFeatureClass functions from snippets.py. Also create the rename lookup tables in .csv format:

Field to Field Alias lookup (att_code-name_lookup.csv):

Attrib_Name,Alias_Name
CODE,Specification Code
VALDATE,Validity Date
...

Feature class to FC Alias lookup (fc_code-name_lookup.csv):

"FC_Name","AliasName"
"BS_1250009_0","Navigational Aid"
"BS_1370009_2","Residential Area"
...

and the script:

import sys
sys.path.append('k:/code')
from snippets import GetLibPath, NewObj, CType, OpenFeatureClass
sWorkingDir = "k:/code/"
sFileGDB = sWorkingDir + "blank_canvec.gdb"
sResourceDir = "k:/code/"
sFCAliasFile = sResourceDir + "fc_code-name_lookup.csv"
sAttAliasFile = sResourceDir + "att_code-name_lookup.csv"
sProduct = "ArcEditor"
def BuildFieldAliasLookup():
 lookup = {}
 f = open(sAttAliasFile, "r")
 bFirst = True
 for line in f:
 # Skip first line
 if bFirst:
 bFirst = False
 continue
 sTokens = line.replace('"','').split(',')
 sFieldName = sTokens[0]
 sAlias = sTokens[1]
 lookup[sFieldName] = sAlias
 return lookup
def AlterAlias():
 # Initialize
 from comtypes.client import GetModule
 import arcgisscripting
 sLibPath = GetLibPath()
 GetModule(sLibPath + "esriGeoDatabase.olb")
 GetModule(sLibPath + "esriDataSourcesGDB.olb")
 import comtypes.gen.esriGeoDatabase as esriGeoDatabase
 gp = arcgisscripting.create(9.3)
 try:
 gp.setproduct(sProduct)
 except:
 gp.AddMessage(gp.GetMessages(2))
 # Build field alias lookup table
 AttrLookup = BuildFieldAliasLookup()
 # Open alias file and loop through lines
 f = open(sFCAliasFile, "r")
 bFirst = True
 for line in f:
 # Skip first line
 if bFirst:
 bFirst = False
 continue
 sTokens = line.replace('"','').split(',')
 sFCName = sTokens[0]
 sAlias = sTokens[1]
 print "Processing: ", sFCName
 # Open feature class
 try:
 pFC = OpenFeatureClass(sFCName)
 except:
 print "Could not open ", sFCName
 continue
 # Alter feature class alias
 try:
 pSE = CType(pFC, esriGeoDatabase.IClassSchemaEdit)
 pSE.AlterAliasName(sAlias)
 except:
 print "Error altering class alias"
 continue
 # Alter field aliases
 try:
 for sKey in AttrLookup.keys():
 i = pFC.FindField(sKey)
 if i == -1:
 continue
 sAlias = AttrLookup[sKey]
 pSE.AlterFieldAliasName(sKey, sAlias)
 except:
 print "Error altering field aliases"
 print "Done."
print 'Field <--> Alias lookup table is:', BuildFieldAliasLookup()
print AlterAlias()

• user2035: This is so close to what I need (updating field aliases). What is the OpenFeatureClass portion of snippets look like? Mark's code doesn't have that piece. Thanks
• scw: Hi Jasperoid: you can comment on a specific answer by clicking the 'add comment' link, I've migrated your response on this answer.
• matt wilkie: @Jasperiod, I moved most of Mark's snippets into a module I call parco, which is where OpenFeatureClass is also. I don't remember creating it myself, but maybe I did. Anyway, there it is at line 125.

Answer 3

This code works for me in 9.3.1 ...

public static void TestAlterAlias(IApplication app)
{
 // make a dictionary of old/new names
 Dictionary<string, string> nameDict = new Dictionary<string, string>(StringComparer.CurrentCultureIgnoreCase);
 nameDict.Add("qsectionalias", "qsectionalias2");
 nameDict.Add("sursysalias", "sursysalias2");
 string[] directories = System.IO.Directory.GetDirectories(@"D:\Projects\EmpireOil\data",@"*.gdb",
 System.IO.SearchOption.TopDirectoryOnly);
 foreach(string dir in directories)
 {
 List<IName> fcnames = GetFCNames(dir);
 foreach (IName fcName in fcnames)
 {
 ChangeFieldAliases(fcName, nameDict);
 }
 }
}
public static void ChangeFieldAliases(IName fcName, Dictionary<string, string> aliasDict)
{
 IFeatureClass fc = (IFeatureClass)fcName.Open();
 IClassSchemaEdit3 cse = (IClassSchemaEdit3)fc;
 ((ISchemaLock)fc).ChangeSchemaLock(esriSchemaLock.esriExclusiveSchemaLock);
 SortedList<string, string> changeList = new SortedList<string, string>();
 for (int i = 0; i < fc.Fields.FieldCount; i++)
 {
 string fldName = fc.Fields.get_Field(i).Name;
 string alias = fc.Fields.get_Field(i).AliasName;
 if (aliasDict.ContainsKey(alias))
 {
 changeList.Add(fldName, aliasDict[alias]);
 // set it blank for now, to avoid problems if two fields have same aliasname.
 cse.AlterFieldAliasName(fldName, "");
 }
 }
 // change the alias
 foreach (KeyValuePair<string, string> kvp in changeList)
 cse.AlterFieldAliasName(kvp.Key, kvp.Value);
 ((ISchemaLock)fc).ChangeSchemaLock(esriSchemaLock.esriSharedSchemaLock);
}
public static List<IName> GetFCNames(string wsPath)
{
 List<IName> names = new List<IName>();
 IWorkspaceFactory wsf = new ESRI.ArcGIS.DataSourcesGDB.FileGDBWorkspaceFactoryClass();
 IWorkspace ws = wsf.OpenFromFile(wsPath, 0);
 IEnumDatasetName enumName = ws.get_DatasetNames(esriDatasetType.esriDTAny);
 enumName.Reset();
 IDatasetName dsName = null;
 while ((dsName = enumName.Next()) != null)
 {
 if(dsName is IFeatureClassName)
 names.Add((IName)dsName);
 else if(dsName is IFeatureDatasetName)
 {
 IEnumDatasetName enumName2 = dsName.SubsetNames;
 enumName2.Reset();
 IDatasetName dsName2;
 while((dsName2=enumName2.Next())!= null)
 {
 if(dsName2 is IFeatureClassName)
 names.Add((IName)dsName2);
 }
 }
 }
 return names;
}

• matt wilkie: thanks Kirk, you've no idea how long I've been trying to figure this out. I'm guessing this is C#?
• Kirk Kuykendall: Yes, C#. Didn't test with featuredatasets though, but should work.

Answer 4

Another solution courtesy of Rob Clark:

You could use featureclass_to_featureclass with field mapping. Yes it creates another feature class but you could just have an output area to copy data and change aliases whilst it's doing it.

FC to FC dialog with Properties open (from context menu)

In python the syntax for the field_map part is tricky so go through it once interactively to set the parameters straight, let it run. Then go to results window, r-click and Copy python snippet. Here is a snippet re-combined into something a little easier to extend and re-use (more work could be done to break apart the pieces of the field map and properties):

inFC = 'e:/Canvec/fix.gdb/HD_1480009_2'
outFC = 'HD_with_aliases'
out_wspace = 'e:/canvec/fix.gdb'
where_clause = '#' # use default
config_keyword = '#' # "
# build field map
fmap_out_att = 'CODE /\Specification code/\ ' # field and alias name
fmap_properties = 'true true false 4 Long 0 0 ,First,#,' # field properties
fmap_in_att = 'e:/Canvec/fix.gdb/HD_1480009_2,CODE,-1,-1' # input FC and field
# construct the complete field map
field_map = fmap_out_att + fmap_properties + fmap_in_att
 # results in:
 # "CODE /\Specification code/\ true true false 4 Long 0 0 ,First,#,e:/Canvec/fix.gdb/HD_1480009_2,CODE,-1,-1"
arcpy.FeatureClassToFeatureClass_conversion(inFC, out_wspace, outFC, 
 where_clause, field_map, config_keyword)
# the template command copied from Results window, used for building above
# arcpy.FeatureClassToFeatureClass_conversion("e:/Canvec/fix.gdb/HD_1480009_2","e:/canvec/fix.gdb","HD_with_aliases3","#","CODE /\Specification code/\ true true false 4 Long 0 0 ,First,#,e:/Canvec/fix.gdb/HD_1480009_2,CODE,-1,-1","#")

Answer 5

This solution is for user that use SQL server as geodatabase. you can manually change it by an SQL update command. all feature's name save in [sde].[GDB_OBJECTCLASSES] table. the alias name set simply if you change the alias column value .

UPDATE [sde].[sde].[GDB_OBJECTCLASSES] 
SET AliasName = 'an alias name' 
WHERE Name='your feature class name'

EDIT: this method is fast method for changing the alias name . but using IClassSchemaEdit is better because in sql update method you can't use alias name until reset feature workspace.

Public Sub SetAliasName(FeatureClass As IFeatureClass, AliasName As String)
 Dim abjTable As ITable = FeatureClass
 Dim objClass As IObjectClass = abjTable
 Dim edit As IClassSchemaEdit = objClass
 edit.AlterAliasName(AliasName)
End Sub

• matt wilkie: So obvious now that I think about it! The same approach should be possible using a Personal GDB (Access .mdb) or any of the RDBMS storage options as well.
• Mehdi: for find it in other RDBMS i think it's better to copy a backup from your RDBMS and then change the alias name by ArcCatalog then compare current database with the backup you can see the changes and find out where aliasname save.