Relations: Fix descendants query to exclude parent item

[iOvergaard]

Summary

• Fixed the GetPagedDescendantsInReferences SQL query to only return actual descendants, not the parent item itself
• The trash confirmation dialog was incorrectly showing the item being deleted in the "descending items with dependencies" list

Fixes AD#61182

Root Cause

The WhereLike query was using just % as suffix, which matched both the parent path and descendants:

• WHERE path LIKE '-1,1000%' matches -1,1000 (parent) AND -1,1000,1001 (child)

Fix

Added , before the % wildcard to only match items whose path continues after the parent:

• WHERE path LIKE '-1,1000,%' only matches -1,1000,1001 (child), NOT -1,1000 (parent)

Screenshot before (notice the Home node)

Screenshot after

API output before

{
    "total": 3,
    "items": [
        {
            "id": "3af0f367-d7ca-4438-a38a-17ef4699c254"
        },
        {
            "id": "607c17c1-d6cf-4739-b330-452436e25064"
        },
        {
            "id": "4db95763-5f0b-4065-9c03-58b0702e4483"
        }
    ]
}

API output after

{
    "total": 2,
    "items": [
        {
            "id": "607c17c1-d6cf-4739-b330-452436e25064"
        },
        {
            "id": "4db95763-5f0b-4065-9c03-58b0702e4483"
        }
    ]
}

Test plan

• Create content with child items that have references (e.g., linked by other content)
• Try to trash the parent item
• Verify the "descending items with dependencies" section only shows children, not the parent itself

Related

• PBI: https://dev.azure.com/umbraco/D-Team%20Tracker/_workitems/edit/61182

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR fixes a SQL query bug in the GetPagedDescendantsInReferences method that was incorrectly including the parent item in its own descendants list. The issue occurred when showing the trash confirmation dialog, where the item being deleted would appear in the "descending items with dependencies" section. The fix adds a comma before the wildcard in the LIKE pattern (,% instead of just %) to ensure only actual descendants are matched, not the parent path itself.

Key changes:

• Modified the WhereLike query to use ",%" suffix instead of default "%" to properly exclude the parent item
• Updated the inline comment to document this exclusion behavior

[AndyButland]

Works as expected, thanks @iOvergaard. I'll merge this and mark it as fixed for 17.1.