diff --git a/internal/database/base.go b/internal/database/base.go
index 32a725b..447b90f 100644
--- a/internal/database/base.go
+++ b/internal/database/base.go
@@ -95,7 +95,14 @@ func (a *BaseAdapter) InsertMany(ctx context.Context, collection string, docs []
 	defer stmt.Close()
 
 	for _, doc := range docs {
-		jsonData, err := json.Marshal(doc.Data)
+		// 创建包含 _id 的新 Data 字段
+		dataWithID := make(map[string]interface{})
+		for k, v := range doc.Data {
+			dataWithID[k] = v
+		}
+		dataWithID["_id"] = doc.ID
+
+		jsonData, err := json.Marshal(dataWithID)
 		if err != nil {
 			return err
 		}
diff --git a/internal/database/dm8/adapter.go b/internal/database/dm8/adapter.go
index a014259..a7b16ad 100644
--- a/internal/database/dm8/adapter.go
+++ b/internal/database/dm8/adapter.go
@@ -99,7 +99,14 @@ func (a *DM8Adapter) InsertMany(ctx context.Context, collection string, docs []t
 	defer tx.Rollback()
 
 	for _, doc := range docs {
-		jsonData, err := json.Marshal(doc.Data)
+		// 创建包含 _id 的新 Data 字段
+		dataWithID := make(map[string]interface{})
+		for k, v := range doc.Data {
+			dataWithID[k] = v
+		}
+		dataWithID["_id"] = doc.ID
+
+		jsonData, err := json.Marshal(dataWithID)
 		if err != nil {
 			return err
 		}
diff --git a/internal/database/postgres/adapter.go b/internal/database/postgres/adapter.go
index e7b9481..d4e0ad0 100644
--- a/internal/database/postgres/adapter.go
+++ b/internal/database/postgres/adapter.go
@@ -98,7 +98,14 @@ func (a *PostgresAdapter) InsertMany(ctx context.Context, collection string, doc
 	defer tx.Rollback()
 
 	for _, doc := range docs {
-		jsonData, err := json.Marshal(doc.Data)
+		// 创建包含 _id 的新 Data 字段
+		dataWithID := make(map[string]interface{})
+		for k, v := range doc.Data {
+			dataWithID[k] = v
+		}
+		dataWithID["_id"] = doc.ID
+
+		jsonData, err := json.Marshal(dataWithID)
 		if err != nil {
 			return err
 		}
diff --git a/internal/database/sqlite/adapter.go b/internal/database/sqlite/adapter.go
index e31fb29..e9b3ec1 100644
--- a/internal/database/sqlite/adapter.go
+++ b/internal/database/sqlite/adapter.go
@@ -200,7 +200,14 @@ func (a *SQLiteAdapter) InsertMany(ctx context.Context, collection string, docs
 	defer tx.Rollback()
 
 	for _, doc := range docs {
-		jsonData, err := json.Marshal(doc.Data)
+		// 创建包含 _id 的新 Data 字段
+		dataWithID := make(map[string]interface{})
+		for k, v := range doc.Data {
+			dataWithID[k] = v
+		}
+		dataWithID["_id"] = doc.ID
+
+		jsonData, err := json.Marshal(dataWithID)
 		if err != nil {
 			return err
 		}
diff --git a/internal/engine/crud_handler.go b/internal/engine/crud_handler.go
index 6141c1a..36841f3 100644
--- a/internal/engine/crud_handler.go
+++ b/internal/engine/crud_handler.go
@@ -54,8 +54,8 @@ func (h *CRUDHandler) Insert(ctx context.Context, collection string, docs []map[
 }
 
 // Update 更新文档
-func (h *CRUDHandler) Update(ctx context.Context, collection string, filter types.Filter, update types.Update) (*types.UpdateResult, error) {
-	matched, modified, _, err := h.store.Update(collection, filter, update, false, nil)
+func (h *CRUDHandler) Update(ctx context.Context, collection string, filter types.Filter, update types.Update, upsert bool, arrayFilters []types.Filter) (*types.UpdateResult, error) {
+	matched, modified, upsertedIDs, err := h.store.Update(collection, filter, update, upsert, arrayFilters)
 	if err != nil {
 		return nil, err
 	}
@@ -63,11 +63,24 @@ func (h *CRUDHandler) Update(ctx context.Context, collection string, filter type
 	// 异步持久化到数据库
 	go h.persistToDB(ctx, collection)
 
-	return &types.UpdateResult{
+	result := &types.UpdateResult{
 		OK:        1,
 		N:         matched,
 		NModified: modified,
-	}, nil
+	}
+
+	// 转换 upserted IDs
+	if len(upsertedIDs) > 0 {
+		for i, id := range upsertedIDs {
+			result.Upserted = append(result.Upserted, types.UpsertID{
+				Index: i,
+				ID:    id,
+			})
+		}
+		result.UpsertedN = len(upsertedIDs)
+	}
+
+	return result, nil
 }
 
 // Delete 删除文档
@@ -89,6 +102,11 @@ func (h *CRUDHandler) Delete(ctx context.Context, collection string, filter type
 
 // persistToDB 持久化集合到数据库
 func (h *CRUDHandler) persistToDB(ctx context.Context, collection string) {
+	// 如果没有配置数据库适配器，跳过持久化
+	if h.adapter == nil {
+		return
+	}
+
 	log.Printf("[DEBUG] Starting persist for collection: %s", collection)
 	if err := h.store.SyncToDB(ctx, collection); err != nil {
 		log.Printf("[ERROR] Failed to persist collection %s: %v", collection, err)
diff --git a/internal/protocol/http/server.go b/internal/protocol/http/server.go
index 2447d63..9e5b4a7 100644
--- a/internal/protocol/http/server.go
+++ b/internal/protocol/http/server.go
@@ -270,8 +270,8 @@ func (h *RequestHandler) HandleUpdate(w http.ResponseWriter, r *http.Request, db
 	totalModified := 0
 	upserted := make([]types.UpsertID, 0)
 
-	for _, op := range req.Updates {
-		result, err := h.crud.Update(context.Background(), fullCollection, op.Q, op.U)
+	for idx, op := range req.Updates {
+		result, err := h.crud.Update(context.Background(), fullCollection, op.Q, op.U, op.Upsert, op.ArrayFilters)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
@@ -280,7 +280,13 @@ func (h *RequestHandler) HandleUpdate(w http.ResponseWriter, r *http.Request, db
 		totalMatched += result.N
 		totalModified += result.NModified
 
-		// TODO: 处理 upserted IDs
+		// 合并 upserted IDs
+		for _, uid := range result.Upserted {
+			upserted = append(upserted, types.UpsertID{
+				Index: idx + uid.Index,
+				ID:    uid.ID,
+			})
+		}
 	}
 
 	response := types.UpdateResult{