DOKK / manpages / debian 10 / libmongoc-doc / mongoc_cursor_new_from_command_reply.3.en
MONGOC_CURSOR_NEW_FROM_COMMAND_REPLY(3) MongoDB C Driver MONGOC_CURSOR_NEW_FROM_COMMAND_REPLY(3)

mongoc_cursor_new_from_command_reply - mongoc_cursor_new_from_command_reply()

mongoc_cursor_t *
mongoc_cursor_new_from_command_reply (mongoc_client_t *client,


                                      bson_t *reply,


                                      uint32_t server_id);


   BSON_GNUC_DEPRECATED_FOR (mongoc_cursor_new_from_command_reply_with_opts);


This function is deprecated and should not be used in new code.

Please use mongoc_cursor_new_from_command_reply_with_opts() instead.

When migrating from the deprecated mongoc_cursor_new_from_command_reply() to mongoc_cursor_new_from_command_reply_with_opts(), note that options previously passed to the reply argument (e.g. "batchSize") must instead be provided in the opts argument.

  • client: A mongoc_client_t.
  • reply: The reply to a command, such as "aggregate", "find", or "listCollections", that returns a cursor document. The reply is destroyed by mongoc_cursor_new_from_command_reply and must not be accessed afterward.
  • server_id: The opaque id of the server used to execute the command.

Some MongoDB commands return a "cursor" document. For example, given an "aggregate" command:

{ "aggregate" : "collection", "pipeline" : [], "cursor" : {}}


The server replies:

{


   "cursor" : {


      "id" : 1234,


      "ns" : "db.collection",


      "firstBatch" : [ ]


   },


   "ok" : 1
}


mongoc_cursor_new_from_command_reply is a low-level function that initializes a mongoc_cursor_t from such a reply. Additional options such as "tailable" or "awaitData" can be included in the reply.

When synthesizing a completed cursor response that has no more batches (i.e. with cursor id 0), set server_id to 0 as well.

Use this function only for building a language driver that wraps the C Driver. When writing applications in C, higher-level functions such as mongoc_collection_aggregate are more appropriate, and ensure compatibility with a range of MongoDB versions.

A mongoc_cursor_t. On failure, the cursor's error is set. Check for failure with mongoc_cursor_error.

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February 23, 2019 1.14.0