From 6b6d55e6c72e1ab18c7cf52a3526f2b41e3a2b82 Mon Sep 17 00:00:00 2001
From: "lancedb-gatefixer[bot]"
 <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
Date: Tue, 6 Oct 2026 16:14:57 -0700
Subject: [PATCH] fix: accept updated_rows in remote update responses (#4444)

Remote update responses report their count as `updated_rows`, but the
client only recognized `rows_updated` and silently defaulted the count
to zero. Python sync/async and TypeScript both use this Rust result.

Accept `updated_rows` as a Serde alias while retaining `rows_updated`
and compatibility with older responses. Extend the remote mock test to
cover both keys, zero and missing counts, returned versions, and empty
responses, with and without a predicate.

Validation:

- Both nonzero `updated_rows` regression cases failed before the fix (0
instead of 5); all 11 focused remote tests pass after it.
- All 3 native update tests pass.
- `cargo fmt --all`
- `cargo clippy --quiet --profile ci --features remote -p lancedb
--tests --examples`

Fixes #4443

<!-- lance-gatekeeper-fix:v1 agent=423249073212c9840d96ccf6d4452905
generation=1 -->

---------

Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
---
 rust/lancedb/src/remote/table.rs | 45 ++++++++++++++++++--------------
 rust/lancedb/src/table/update.rs |  2 +-
 2 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/rust/lancedb/src/remote/table.rs b/rust/lancedb/src/remote/table.rs
index 35114cded..1ea72bf14 100644
--- a/rust/lancedb/src/remote/table.rs
+++ b/rust/lancedb/src/remote/table.rs
@@ -4620,10 +4620,18 @@ mod tests {
     }
 
     #[rstest]
-    #[case(true)]
-    #[case(false)]
+    #[case::old_server("", 0, 0)]
+    #[case::rows_updated(r#"{"rows_updated": 5, "version": 43}"#, 5, 43)]
+    #[case::updated_rows(r#"{"updated_rows": 5, "version": 43}"#, 5, 43)]
+    #[case::zero_updated_rows(r#"{"updated_rows": 0, "version": 43}"#, 0, 43)]
+    #[case::missing_row_count(r#"{"version": 43}"#, 0, 43)]
     #[tokio::test]
-    async fn test_update(#[case] old_server: bool) {
+    async fn test_update(
+        #[case] response_body: &'static str,
+        #[case] expected_rows_updated: u64,
+        #[case] expected_version: u64,
+        #[values(true, false)] filtered: bool,
+    ) {
         let table = Table::new_with_handler("my_table", move |request| {
             if request.url().path() == "/v1/table/my_table/update/" {
                 assert_eq!(request.method(), "POST");
@@ -4648,32 +4656,29 @@ mod tests {
                     assert_eq!(col_name, "b");
                     assert_eq!(expression, "b - 1");
 
-                    let only_if = value.get("predicate").unwrap().as_str().unwrap();
-                    assert_eq!(only_if, "`B` > 10");
+                    assert_eq!(
+                        value.get("predicate").unwrap(),
+                        &serde_json::json!(if filtered { Some("`B` > 10") } else { None })
+                    );
                 }
 
-                if old_server {
-                    http::Response::builder().status(200).body("").unwrap()
-                } else {
-                    http::Response::builder()
-                        .status(200)
-                        .body(r#"{"rows_updated": 5, "version": 43}"#)
-                        .unwrap()
-                }
+                http::Response::builder()
+                    .status(200)
+                    .body(response_body)
+                    .unwrap()
             } else {
                 panic!("Unexpected request path: {}", request.url().path());
             }
         });
 
-        let update = table
-            .update()
-            .column("a", "a + 1")
-            .column("b", "b - 1")
-            .only_if(r#""B" > 10"#);
+        let mut update = table.update().column("a", "a + 1").column("b", "b - 1");
+        if filtered {
+            update = update.only_if(r#""B" > 10"#);
+        }
         let result = table.base_table().update(update).await.unwrap();
 
-        assert_eq!(result.version, if old_server { 0 } else { 43 });
-        assert_eq!(result.rows_updated, if old_server { 0 } else { 5 });
+        assert_eq!(result.version, expected_version);
+        assert_eq!(result.rows_updated, expected_rows_updated);
     }
 
     #[tokio::test]
diff --git a/rust/lancedb/src/table/update.rs b/rust/lancedb/src/table/update.rs
index f10594f23..5ffcb74a9 100644
--- a/rust/lancedb/src/table/update.rs
+++ b/rust/lancedb/src/table/update.rs
@@ -13,7 +13,7 @@ use crate::Result;
 /// The result of an update operation
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default)]
 pub struct UpdateResult {
-    #[serde(default)]
+    #[serde(default, alias = "updated_rows")]
     pub rows_updated: u64,
     /// The commit version associated with the operation.
     #[serde(default)]