Throw an error when ordering by aggregation function over an empty path

crates/query-engine/translation/src/translation/query/sorting.rs

@@ -276,6 +276,14 @@ fn translate_order_by_target_for_column(
     )?;
 
     if path.is_empty() {
+        // if we got an aggregation function, the query does not make sense.
+        match function {
+            None => Ok(())?,
+            Some(func) => Err(Error::NotSupported(format!(
+                "Cannot order by aggregation function '{func}' on the same table"
+            )))?,
+        };
+
         // if there were no relationship columns, we don't need to build a query, just return the column.
         let table = env.lookup_collection(&root_and_current_tables.current_table.name)?;
         let selected_column = table.lookup_column(&column_name)?;

crates/query-engine/translation/tests/goldenfiles/sorting_by_no_relationship_aggregate/request.json

@@ -0,0 +1,28 @@
+{
+  "collection": "Album",
+  "query": {
+    "fields": {
+      "Name": {
+        "type": "column",
+        "column": "Title",
+        "arguments": {}
+      }
+    },
+    "order_by": {
+      "elements": [
+        {
+          "target": {
+            "type": "single_column_aggregate",
+            "column": "TopRadioChartPlacement",
+            "function": "impossible",
+            "path": [ ]
+          },
+          "order_direction": "desc"
+        }
+      ]
+    },
+    "limit": 3
+  },
+  "arguments": {},
+  "collection_relationships": {}
+}

crates/query-engine/translation/tests/goldenfiles/sorting_by_no_relationship_aggregate/tables.json

@@ -0,0 +1,23 @@
+{
+  "tables": {
+    "Album": {
+      "schemaName": "public",
+      "tableName": "Album",
+      "columns": {
+        "AlbumId": {
+          "name": "AlbumId",
+          "type": "int4"
+        },
+        "Title": {
+          "name": "Title",
+          "type": "varchar"
+        },
+        "TopRadioChartPlacement": {
+          "name": "TopRadioChartPlacement",
+          "type": "int4",
+          "nullable": "nullable"
+        }
+      }
+    }
+  }
+}

crates/query-engine/translation/tests/snapshots/tests__sorting_by_no_relationship_aggregate.snap

@@ -0,0 +1,5 @@
+---
+source: crates/query-engine/translation/tests/tests.rs
+expression: "format!(\"{result:?}\")"
+---
+Err(NotSupported("Cannot order by aggregation function 'impossible' on the same table"))

crates/query-engine/translation/tests/tests.rs

@@ -141,6 +141,12 @@ fn sorting_by_nested_relationship_count() {
     insta::assert_snapshot!(result);
 }
 
+#[test]
+fn sorting_by_no_relationship_aggregate() {
+    let result = common::test_translation("sorting_by_no_relationship_aggregate");
+    insta::assert_snapshot!(format!("{result:?}"));
+}
+
 #[test]
 fn sorting_by_relationship_count_with_predicate() {
     let result = common::test_translation("sorting_by_relationship_count_with_predicate").unwrap();