Editing View-Based Layers

GISquirrel feature classes based on SQL views may or may not be editable. If a view is detected to be non-editable, the user will be shows a warning message and it will not be possible to start an editing session.

A view is deemed potentially editable if

1. the user has the requisite permissions AND
2. the view is based on a single table OR
3. the view has INSTEAD OF triggers/rules defined for UPDATE, INSERT and DELETE (all three are required).
   GISquirrel will not create these triggers but check for their presence and treat a view-based layer as editable when they are found. Please note that given the lack of regular expressions in Microsoft T-SQL, SQL Server trigger definitions are assumed to be formatted with exactly one space between SQL keywords.

However a view that obeys these rules may still not be editable due to:

• Columns based on expressions.
• Missing fields from the base table that require values.

The only sure way to find out is to start an GISquirrel editing session, make a small change (e.g. add a single feature), and attempt to save. If the save operation fails you will be shown a message explaining the reason, which could either be a bad geometry or that the view is not editable through GISquirrel.

Attribute domains can be configured for view-based feature classes, by editing the “arcsquirreldomains” table as described here. However note that default values are not supported when editing feature classes based on views.