Refa: dataset operations to simplify error handling (#8132)

### What problem does this PR solve?

- Consolidate database operations within single try-except blocks in the
methods

### Type of change

- [x] Refactoring

api/apps/sdk/dataset.py

     try:
         if KnowledgebaseService.get_or_none(name=req["name"], tenant_id=tenant_id, status=StatusEnum.VALID.value):
             return get_error_operating_result(message=f"Dataset name '{req['name']}' already exists")
-    except OperationalError as e:
-        logging.exception(e)
-        return get_error_data_result(message="Database operation failed")
 
-    req["parser_config"] = get_parser_config(req["parser_id"], req["parser_config"])
-    req["id"] = get_uuid()
-    req["tenant_id"] = tenant_id
-    req["created_by"] = tenant_id
+        req["parser_config"] = get_parser_config(req["parser_id"], req["parser_config"])
+        req["id"] = get_uuid()
+        req["tenant_id"] = tenant_id
+        req["created_by"] = tenant_id
 
-    try:
         ok, t = TenantService.get_by_id(tenant_id)
         if not ok:
             return get_error_permission_result(message="Tenant not found")
-    except OperationalError as e:
-        logging.exception(e)
-        return get_error_data_result(message="Database operation failed")
 
-    if not req.get("embd_id"):
-        req["embd_id"] = t.embd_id
-    else:
-        ok, err = verify_embedding_availability(req["embd_id"], tenant_id)
-        if not ok:
-            return err
+        if not req.get("embd_id"):
+            req["embd_id"] = t.embd_id
+        else:
+            ok, err = verify_embedding_availability(req["embd_id"], tenant_id)
+            if not ok:
+                return err
 
-    try:
         if not KnowledgebaseService.save(**req):
             return get_error_data_result(message="Create dataset error.(Database error)")
-    except OperationalError as e:
-        logging.exception(e)
-        return get_error_data_result(message="Database operation failed")
 
-    try:
         ok, k = KnowledgebaseService.get_by_id(req["id"])
         if not ok:
             return get_error_data_result(message="Dataset created failed")
+
+        response_data = remap_dictionary_keys(k.to_dict())
+        return get_result(data=response_data)
     except OperationalError as e:
         logging.exception(e)
         return get_error_data_result(message="Database operation failed")
 
-    response_data = remap_dictionary_keys(k.to_dict())
-    return get_result(data=response_data)
-
 
 @manager.route("/datasets", methods=["DELETE"])  # noqa: F821
 @token_required
     if err is not None:
         return get_error_argument_result(err)
 
-    kb_id_instance_pairs = []
-    if req["ids"] is None:
-        try:
+    try:
+        kb_id_instance_pairs = []
+        if req["ids"] is None:
             kbs = KnowledgebaseService.query(tenant_id=tenant_id)
             for kb in kbs:
                 kb_id_instance_pairs.append((kb.id, kb))
-        except OperationalError as e:
-            logging.exception(e)
-            return get_error_data_result(message="Database operation failed")
-    else:
-        error_kb_ids = []
-        for kb_id in req["ids"]:
-            try:
+
+        else:
+            error_kb_ids = []
+            for kb_id in req["ids"]:
                 kb = KnowledgebaseService.get_or_none(id=kb_id, tenant_id=tenant_id)
                 if kb is None:
                     error_kb_ids.append(kb_id)
                     continue
                 kb_id_instance_pairs.append((kb_id, kb))
-            except OperationalError as e:
-                logging.exception(e)
-                return get_error_data_result(message="Database operation failed")
-        if len(error_kb_ids) > 0:
-            return get_error_permission_result(message=f"""User '{tenant_id}' lacks permission for datasets: '{", ".join(error_kb_ids)}'""")
-
-    errors = []
-    success_count = 0
-    for kb_id, kb in kb_id_instance_pairs:
-        try:
+            if len(error_kb_ids) > 0:
+                return get_error_permission_result(message=f"""User '{tenant_id}' lacks permission for datasets: '{", ".join(error_kb_ids)}'""")
+
+        errors = []
+        success_count = 0
+        for kb_id, kb in kb_id_instance_pairs:
             for doc in DocumentService.query(kb_id=kb_id):
                 if not DocumentService.remove_document(doc, tenant_id):
                     errors.append(f"Remove document '{doc.id}' error for dataset '{kb_id}'")
                 errors.append(f"Delete dataset error for {kb_id}")
                 continue
             success_count += 1
-        except OperationalError as e:
-            logging.exception(e)
-            return get_error_data_result(message="Database operation failed")
 
-    if not errors:
-        return get_result()
+        if not errors:
+            return get_result()
 
-    error_message = f"Successfully deleted {success_count} datasets, {len(errors)} failed. Details: {'; '.join(errors)[:128]}..."
-    if success_count == 0:
-        return get_error_data_result(message=error_message)
+        error_message = f"Successfully deleted {success_count} datasets, {len(errors)} failed. Details: {'; '.join(errors)[:128]}..."
+        if success_count == 0:
+            return get_error_data_result(message=error_message)
 
-    return get_result(data={"success_count": success_count, "errors": errors[:5]}, message=error_message)
+        return get_result(data={"success_count": success_count, "errors": errors[:5]}, message=error_message)
+    except OperationalError as e:
+        logging.exception(e)
+        return get_error_data_result(message="Database operation failed")
 
 
 @manager.route("/datasets/<dataset_id>", methods=["PUT"])  # noqa: F821
         kb = KnowledgebaseService.get_or_none(id=dataset_id, tenant_id=tenant_id)
         if kb is None:
             return get_error_permission_result(message=f"User '{tenant_id}' lacks permission for dataset '{dataset_id}'")
-    except OperationalError as e:
-        logging.exception(e)
-        return get_error_data_result(message="Database operation failed")
 
-    if req.get("parser_config"):
-        req["parser_config"] = deep_merge(kb.parser_config, req["parser_config"])
+        if req.get("parser_config"):
+            req["parser_config"] = deep_merge(kb.parser_config, req["parser_config"])
 
-    if (chunk_method := req.get("parser_id")) and chunk_method != kb.parser_id:
-        if not req.get("parser_config"):
-            req["parser_config"] = get_parser_config(chunk_method, None)
-    elif "parser_config" in req and not req["parser_config"]:
-        del req["parser_config"]
+        if (chunk_method := req.get("parser_id")) and chunk_method != kb.parser_id:
+            if not req.get("parser_config"):
+                req["parser_config"] = get_parser_config(chunk_method, None)
+        elif "parser_config" in req and not req["parser_config"]:
+            del req["parser_config"]
 
-    if "name" in req and req["name"].lower() != kb.name.lower():
-        try:
+        if "name" in req and req["name"].lower() != kb.name.lower():
             exists = KnowledgebaseService.get_or_none(name=req["name"], tenant_id=tenant_id, status=StatusEnum.VALID.value)
             if exists:
                 return get_error_data_result(message=f"Dataset name '{req['name']}' already exists")
-        except OperationalError as e:
-            logging.exception(e)
-            return get_error_data_result(message="Database operation failed")
-
-    if "embd_id" in req:
-        if kb.chunk_num != 0 and req["embd_id"] != kb.embd_id:
-            return get_error_data_result(message=f"When chunk_num ({kb.chunk_num}) > 0, embedding_model must remain {kb.embd_id}")
-        ok, err = verify_embedding_availability(req["embd_id"], tenant_id)
-        if not ok:
-            return err
 
-    try:
+        if "embd_id" in req:
+            if kb.chunk_num != 0 and req["embd_id"] != kb.embd_id:
+                return get_error_data_result(message=f"When chunk_num ({kb.chunk_num}) > 0, embedding_model must remain {kb.embd_id}")
+            ok, err = verify_embedding_availability(req["embd_id"], tenant_id)
+            if not ok:
+                return err
+
         if not KnowledgebaseService.update_by_id(kb.id, req):
             return get_error_data_result(message="Update dataset error.(Database error)")
-    except OperationalError as e:
-        logging.exception(e)
-        return get_error_data_result(message="Database operation failed")
 
-    try:
         ok, k = KnowledgebaseService.get_by_id(kb.id)
         if not ok:
             return get_error_data_result(message="Dataset created failed")
+
+        response_data = remap_dictionary_keys(k.to_dict())
+        return get_result(data=response_data)
     except OperationalError as e:
         logging.exception(e)
         return get_error_data_result(message="Database operation failed")
 
-    response_data = remap_dictionary_keys(k.to_dict())
-    return get_result(data=response_data)
-
 
 @manager.route("/datasets", methods=["GET"])  # noqa: F821
 @token_required
     if err is not None:
         return get_error_argument_result(err)
 
-    kb_id = request.args.get("id")
-    name = args.get("name")
-    if kb_id:
-        try:
+    try:
+        kb_id = request.args.get("id")
+        name = args.get("name")
+        if kb_id:
             kbs = KnowledgebaseService.get_kb_by_id(kb_id, tenant_id)
-        except OperationalError as e:
-            logging.exception(e)
-            return get_error_data_result(message="Database operation failed")
-        if not kbs:
-            return get_error_permission_result(message=f"User '{tenant_id}' lacks permission for dataset '{kb_id}'")
-    if name:
-        try:
+
+            if not kbs:
+                return get_error_permission_result(message=f"User '{tenant_id}' lacks permission for dataset '{kb_id}'")
+        if name:
             kbs = KnowledgebaseService.get_kb_by_name(name, tenant_id)
-        except OperationalError as e:
-            logging.exception(e)
-            return get_error_data_result(message="Database operation failed")
-        if not kbs:
-            return get_error_permission_result(message=f"User '{tenant_id}' lacks permission for dataset '{name}'")
+            if not kbs:
+                return get_error_permission_result(message=f"User '{tenant_id}' lacks permission for dataset '{name}'")
 
-    try:
         tenants = TenantService.get_joined_tenants_by_user_id(tenant_id)
         kbs = KnowledgebaseService.get_list(
             [m["tenant_id"] for m in tenants],
             kb_id,
             name,
         )
+
+        response_data_list = []
+        for kb in kbs:
+            response_data_list.append(remap_dictionary_keys(kb))
+        return get_result(data=response_data_list)
     except OperationalError as e:
         logging.exception(e)
         return get_error_data_result(message="Database operation failed")
-
-    response_data_list = []
-    for kb in kbs:
-        response_data_list.append(remap_dictionary_keys(kb))
-    return get_result(data=response_data_list)