[Copilot]

Why make this change?

MCP aggregate_records appends numeric aggregate ordering outside DWSQL’s grouped derived table, where raw measure columns are no longer available. Fabric Warehouse rejects these queries with Invalid column name.

What is this change?

• Ordering: Insert alias-based ORDER BY inside the grouped query for DWSQL’s STRING_AGG path.
• Pagination: Place OFFSET/FETCH in the same scope.
• Compatibility: Preserve SQL Server and optimized DWSQL query behavior.

How was this tested?

• Integration Tests
• Unit Tests

Sample Request(s)

{
  "method": "tools/call",
  "params": {
    "name": "aggregate_records",
    "arguments": {
      "entity": "my_view",
      "function": "sum",
      "field": "amount",
      "groupby": ["category"]
    }
  }
}

The grouped query uses ORDER BY [sum_amount] DESC before the derived-table boundary.

• Fixes [Bug]: aggregate_records (MCP) generates an invalid default ORDER BY SUM(<raw column>) against the grouped derived table on dwsql (Microsoft Fabric Warehouse) → Invalid column name #3695

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[Copilot]

🟡 Changes recommended

The unordered outer STRING_AGG can violate the requested sort order and cause pagination to skip or repeat groups, requiring matching WITHIN GROUP ordering.

1 open issue

• Add ordering to STRING_AGG to preserve paginated result order · New

What changed in this PR

This PR addresses #3695 by moving MCP grouped aggregate ordering into the correct DWSQL query scope, avoiding references to raw columns outside the grouped derived table.

Changes:

• Uses aggregate aliases for ordering inside DWSQL’s STRING_AGG derived table.
• Places pagination in the same scope while retaining the existing FOR JSON PATH handling.
• Adds query-generation tests covering aggregate functions, sort directions, distinct values, pagination, and both DWSQL query paths.

File	Description
src/​Service.Tests/​Mcp/​AggregateRecordsToolTests.cs	Adds DWSQL grouped ordering and pagination regression tests.
src/​Azure.DataApiBuilder.Mcp/​BuiltInTools/​AggregateRecordsTool.cs	Adjusts ordering and pagination placement for DWSQL grouped queries.

_{Review effort: Balanced}