NAME

       mongoc_cursor_t - Client-side cursor abtraction

SYNOPSIS

       typedef struct _mongoc_cursor_t mongoc_cursor_t;

       mongoc_cursor_t  provides access to a MongoDB query cursor.  It wraps up the wire protocol
       negotiation required to initiate a query and retrieve an unknown number of documents.

       Cursors are lazy, meaning  that  no  network  traffic  occurs  until  the  first  call  to
       mongoc_cursor_next(3) \&.

       At that point we can:

       \[bu]
         Determine which host we've connected to with mongoc_cursor_get_host(3) \&.

       \[bu]
         Retrieve more records with repeated calls to mongoc_cursor_next(3) \&.

       \[bu]
         Test for more records with mongoc_cursor_more(3)

       \[bu]
         Clone a query to repeat execution at a later point with mongoc_cursor_clone(3) \&.

       \[bu]
         Test for errors with mongoc_cursor_error(3) \&.

THREAD SAFETY

       mongoc_cursor_t  is  NOT  thread  safe. It may only be used from the thread it was created
       from.

EXAMPLE

       /* gcc example.c ‐o example $(pkg‐config ‐‐cflags ‐‐libs libmongoc‐1.0) */

       /* ./example‐client [CONNECTION_STRING [COLLECTION_NAME]] */

       #include <mongoc.h>
       #include <stdio.h>
       #include <stdlib.h>

       int
       main (int   argc,
             char *argv[])
       {
          mongoc_client_t *client;
          mongoc_collection_t *collection;
          mongoc_cursor_t *cursor;
          bson_error_t error;
          const bson_t *doc;
          const char *uristr = "mongodb://127.0.0.1/";
          const char *collection_name = "test";
          bson_t query;
          char *str;

          mongoc_init ();

          if (argc > 1) {
             uristr = argv [1];
          }

          if (argc > 2) {
             collection_name = argv [2];
          }

          client = mongoc_client_new (uristr);

          if (!client) {
             fprintf (stderr, "Failed to parse URI.\n");
             return EXIT_FAILURE;
          }

          bson_init (&query);

       #if 0
          bson_append_utf8 (&query, "hello", ‐1, "world", ‐1);
       #endif

          collection = mongoc_client_get_collection (client, "test", collection_name);
          cursor = mongoc_collection_find (collection,
                                           MONGOC_QUERY_NONE,
                                           0,
                                           0,
                                           0,
                                           &query,
                                           NULL,  /* Fields, NULL for all. */
                                           NULL); /* Read Prefs, NULL for default */

          while (mongoc_cursor_next (cursor, &doc)) {
             str = bson_as_json (doc, NULL);
             fprintf (stdout, "%s\n", str);
             bson_free (str);
          }

          if (mongoc_cursor_error (cursor, &error)) {
             fprintf (stderr, "Cursor Failure: %s\n", error.message);
             return EXIT_FAILURE;
          }

          bson_destroy (&query);
          mongoc_cursor_destroy (cursor);
          mongoc_collection_destroy (collection);
          mongoc_client_destroy (client);

          mongoc_cleanup ();

          return EXIT_SUCCESS;
       }

COLOPHON

       This   page   is   part   of   MongoDB   C   Driver.    Please   report   any   bugs    at
       https://jira.mongodb.org/browse/CDRIVER.