Latest Contributions by Bud

‎05-07-2026

Databases like SQL Server and PostgreSQL (and Oracle) support SQL expression fields right in the table, called computed columns, generated columns, virtual columns, etc. This idea is to make use of such columns by adding an SQL expression field type, right in the AGOL table/hosted feature layer. For example, AGOL > hosted feature layer > Data tab > Fields view > a read-only field > properties > SQL expression: 'SEWER-' || asset_num_integer The other fields would remain editable in ArcGIS apps, which would be ideal. SQL expressions right in the db table would perform better than other expression mechanisms like arcade or even advanced REST API views. A related, but different, ArcGIS Pro idea: Virtual Attributes (ad hoc)

‎05-06-2026

Related: Change editor widget title

‎05-06-2026

I got a notification email from Esri: BUG-000184634 has been closed: Non-Reproducible.

‎05-06-2026

What are the rules when setting default values for AGOL hosted feature layer fields? (using the Admin REST API) For example: Use SQL Server's SQL syntax/dialect. GIS Stack Exchange: What kind of database does ArcGIS Online use to store data? GUID and number fields support expressions, but text fields don't. Idea: Allow expressions in AGOL string field > default value Here's a useful error message I got when trying to use OBJECTID+1 as the default value for an integer field: "Valid expressions are constants, constant expressions, and (in some contexts) variables. Column names are not permitted." Link Are there any other known rules? Or any other useful error messages that could be noted here? (To Esri staff: Could the rules be added to the AGOL docs?)

‎05-06-2026

AGOL hosted feature layers; Experience Builder; editor widget When copying/pasting a feature from Layer1 to Layer2, how does ExB determine what fields to match/copy? I assume it's matching fields that have exactly the same name. Where does the list of fields to copy come from? Does the list of fields come from the AGOL hosted feature layer, the web map, the web map form configuration, the layer in Experience Builder, or the list of fields in the editor widget? True field names or field aliases? I assume true field names. If fields are excluded in the editor widget, do they not get copied/pasted? What are the rules when copying/pasting a feature into a different feature layer?

‎05-06-2026

Idea: Expression field in advanced AGOL view without join It's still unclear if this is supported or not. If it's not supported, it would help if the docs could explain this. Edit: Esri Case #04171628 - ArcGIS Online Admin REST API - Are expression fields in advanced views without joins supported? That workflow is not supported, unfortunately. Expressions can only exist on the parent layer for advanced views which have relatedTable objects within the JSON payload. That approach works for standard fields (not expression fields) but advanced views are read-only and so you could not manually calculate the field after it has been added.

‎05-05-2026

What kind of database does ArcGIS Online use to store data?

‎05-05-2026

Expression fields (calculated columns) in advanced views seem to be limited to joined views. They don’t work with regular view layers. For example, concatenate “SEWER-“ text with an integer field to produce prefixed ASSET_IDs like SEWER-0000001. Documentation: ArcGIS REST APIs > Add to Definition (Feature Service) Question: Create advanced AGOL view with expression field (no joins)? Could expression functionality be added to views that don’t have a joined table?

‎05-04-2026

Summary: Admin REST API > view's sublayer > Add To Definition Added an expression field via JSON It ran without errors, but I don't see the new field in the view. Detailed Steps: I've created a AGOL view called test_layer_view on a hosted feature layer: In the view, using the Admin REST API, I want to add a expression field as a test, calculating 1+1. I'm not using the view's top-level feature layer... ...Instead, I'm using the sublayer: (Let me know if I'm using the wrong item. Although I tested with the top-level feature layer view, and had the same issue with it.) I got some sample JSON from the ArcGIS REST APIs > Add to Definition (Feature Service) documentation: (Those docs are pretty complicated and geared towards joins, so I'm not sure how to boil the sample JSON down to just a simple expression field without a join.) { "sourceLayerFields": [ { "name": "test_expression_field", "alias": "test_expression_field", "expression": "1+1", "type": "esriFieldTypeInteger" } ] } I hit the "Add To Layer Definition" button and it ran without errors: But when I refresh the view's Data > Fields tab (or the Table tab), the expression field is missing. Likewise, the expression field is missing from the sublayer's JSON definition. What am I doing wrong?

‎05-04-2026

AGOL hosted feature layer: For non-string fields like GUIDs and integers, we can set up default value expressions using the Admin REST API: (The user-defined field name is unique_id.) GUID: "defaultValue" : "NEWID()" Inserts a GUID value like 7ec3018d-4a49-4a13-8e15-005846b25848 Integer: "defaultValue" : "IDENT_CURRENT('db_2xxxx.user_2xxxx.test_layer_TEST_LAYER')" Inserts a copy of the Object ID. But for string fields, everything we try to put into a string field just ends up writing the function name and parameters as a literal string, e.g. "CONCAT(v1, v2)". We are trying to insert a sequential integer ID with a text prefix, such as SEWER-0000001. There seems to be a limitation where the system has no way to differentiate a literal string from an expression/function. Could expression functionality be added for string default values? Related AGOL Question: https://community.esri.com/t5/arcgis-online-questions/add-guid-field-to-existing-agol-survey123-feature/m-p/1699854/highlight/true#M68606 @MobiusSnake We're aware that IDs can be generated/inserted at the app level. But there are cases where it'd be preferrable to do it at the AGOL hosted feature layer level, so the IDs are inserted globally, regardless of where the edit is happening.

‎05-04-2026

@MobiusSnake Regarding... "defaultValue" : "NEWID() WITH VALUES" ...in your original JSON definition for a GUID default value: { "fields": [ { "name" : "MyID", "type" : "esriFieldTypeGUID", "alias" : "My ID", "sqlType" : "sqlTypeOther", "length" : 38, "nullable" : false, "editable" : false, "domain" : null, "defaultValue" : "NEWID() WITH VALUES" } ] } As far as I can tell, WITH VALUES doesn't seem to do anything, and can be removed from the JSON. At first, I thought WITH VALUES was responsible for back-populating existing rows. But now I suspect making the field not nullable is responsible for back-populating existing rows. Do you see the same thing on your end?

‎05-04-2026

So far I'm totally stumped on getting any text functions to work ... everything I try to put into a string field just ends up writing the function name and parameters as a literal string, e.g. "CONCAT(v1,v2)" . I'm not sure whether there's a way around that. The same thing happens for me. I wonder if Esri (or an underlying mechanism) has intentionally disabled expressions for text fields for security reasons. Would there be SQL injection concerns? That's not something I know anything about. Whereas, maybe there aren't SQL injection concerns for GUID or integer fields, so expressions are allowed there. Or, does the system just have no way of differentiating a literal string from an expression/function? And GUID & integer fields don't have this problem because strings aren't valid in those fields? Edit - AGOL idea: Allow expressions in AGOL string field > default value

‎05-04-2026

Esri Case #04168794 - ArcGIS Online - Add Field dialog says GUID field length will be 36, but resulting field length is 38 This is expected because 38 includes dashes and brackets. For reference, I've included an example below. (More information regarding this can be found here.) Example: {7ec3018d-4a49-4a13-8e15-005846b25848}

‎05-04-2026

Good point. I have to admit, I haven't used relationship classes much. I'll try them out. Do they automatically populate GUID fields?

‎05-04-2026

Nice find! Replacing the parameter of IDENT_CURRENT with the layer/table's internal table name (you can get this from the layer/table properties in the Admin REST API) gives me a copy of the Object ID. I didn't see the database name, user name, or true table name in the Admin REST API page. But I did find it in the JSON definition of the layer. Is that where you got yours too, or am I missing something in the main Admin REST API page? Also, a couple of observations: This technique doesn't seem to back-populate existing rows properly, when nullable:false. The existing rows will all be set to the same value — the largest OBJECTID. I suppose this could be corrected with a field calculation if the field is editable. Edit: I wonder if we should keep an eye on this in other scenarios. Are there any gotchas? For example, what happens if we bulk load or populate rows? Will it populate the IDs correctly, or will they all be the same value (the largest OBJECTID)? I ended up disabling editing on this field because when editable:true (and when nullable:true), the web map Edit pane was setting the field to null, overriding the default value. This is what I settled on: { "fields": [ { "name" : "unique_id", "type" : "esriFieldTypeInteger", "alias" : "Unique ID", "sqlType" : "sqlTypeOther", "nullable" : true, "editable" : false, "visible" : true, "domain" : null, "defaultValue" : "IDENT_CURRENT('db_2xxxx.user_2xxxx.test_layer_TEST_LAYER')" } ] }

My Ideas

Latest Contributions by Bud

Computed column (SQL expression field) in AGOL table/hosted feature layer

Re: Make widget IDs editable in Experience Builder

Re: Attribute Table — Insert symbol into text value using picklist of common symbols

What are the rules when setting default values for AGOL hosted feature layer fields? (Admin REST API)

Copy/paste feature using editor widget — How does ExB determine what fields to match/copy?

Re: Create advanced AGOL view with expression field (no joins)

Re: Add GUID field to existing AGOL Survey123 feature layer

Expression field in advanced AGOL view without join

Create advanced AGOL view with expression field (no joins)?

Allow expressions in AGOL string field > default value

Re: Add GUID field to existing AGOL Survey123 feature layer — Field not auto-populating?

Re: Add GUID field to existing AGOL Survey123 feature layer

Re: Add Field dialog says GUID field length will be 36, but resulting field length is 38

Re: Add Field dialog says GUID field length will be 36, but resulting field length is 38

Re: Add GUID field to existing AGOL Survey123 feature layer

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