How to alter field?

[RejeanLabbe]

I try to alter a field size and alias using Geoprocessing Tool. Even if there is no error, the field is not altered.

List<object> oParams = new List<object>();

oParams.Add(oGeodatabase.GetPath().AbsolutePath);
oParams.Add(sTableName);
oParams.Add(sFieldName);
oParams.Add(sNewFieldName);
oParams.Add(sNewAlias);
oParams.Add("TEXT");
oParams.Add(60); // The actual field size is 50

var parameters = Geoprocessing.MakeValueArray(oParams);
var gpResult = Geoprocessing.ExecuteToolAsync("management.AlterField", parameters, null, CancelableProgressor.None, GPExecuteToolFlags.None);

Python script can be find here :
https://pro.arcgis.com/fr/pro-app/2.9/tool-reference/data-management/alter-field-properties.htm

I used the same syntax for AddCodedValueToDomain and it works, so I know that my geodatabase parameter is correct.

[GKmieliauskas · Accepted solution]

Hi,

You have wrong parameters list. TableName and geodatabase path must be combined together:

var parameters = Geoprocessing.MakeValueArray(Path.Combine(oGeodatabase.GetPath().AbsolutePath, sTableName), sFieldName, sNewFieldName, sNewAlias, "TEXT");
var gpResult = Geoprocessing.ExecuteToolAsync("management.AlterField", parameters, null, CancelableProgressor.None, GPExecuteToolFlags.None);

You can change field type if the input table is empty (does not contain records)

[RejeanLabbe]

Thank Gintautas. Unfortunately, this doesn't work. Have you tried it?

I tried multiple combinations but nothing works :

Path.Combine(oGeodatabase.GetPath().LocalPath, sTableName)
// or
oGeodatabase.GetPath().AbsolutePath + "/" + sTableName

I tried to change only the alias, but the change is not applied.

[GKmieliauskas]

Yes, I have tried. It does not work on shapefile but works with gdb table. I have tried to change field name. alias name and length of TEXT field. There is some limitation with field type changing

Have you checked what you get from oGeodatabase.GetPath().LocalPath ?

[RejeanLabbe · Accepted solution]

Thanks Gintautas.

Combining the geodatabase path and the table name did the trick.

However, I had another issue with my parameter list.

This is my final working code :

List<string> oParams = new List<string>();

oParams.Add(Path.Combine(oGeodatabase.GetPath().AbsolutePath, sTableName));
oParams.Add(sFieldName);
oParams.Add(sNewFieldName);
oParams.Add(sNewAlias);
oParams.Add(sFieldType);

if (sFieldType == "TEXT" || sFieldType == "BLOB") {
	oParams.Add(sSize); // The field size must be the same or greater
}

var gpResult = Geoprocessing.ExecuteToolAsync("management.AlterField", oParams, null, CancelableProgressor.None, GPExecuteToolFlags.None);