plucky (3) mongoc_collection_command.3.gz

WARNING:

          Deprecated  since version 1.29.0: This function is deprecated and should not be used in new code.  Use
          mongoc_collection_command_simple() instead.

SYNOPSIS

          mongoc_cursor_t *
          mongoc_collection_command (mongoc_collection_t *collection,
                                     mongoc_query_flags_t flags,
                                     uint32_t skip,
                                     uint32_t limit,
                                     uint32_t batch_size,
                                     const bson_t *command,
                                     const bson_t *fields,
                                     const mongoc_read_prefs_t *read_prefs);

       This function is not considered a retryable read operation.

PARAMETERS

       • collection: A mongoc_collection_t.

       • flags: Unused.

       • skip: Unused.

       • limit: Unused.

       • batch_size: Unused.

       • command: A bson_t containing the command to execute.

       • fields: Unused.

       • read_prefs: An optional mongoc_read_prefs_t. Otherwise, the command uses mode MONGOC_READ_PRIMARY.

MIGRATING

       mongoc_collection_command() is deprecated.

       The following example uses mongoc_collection_command():

       Before

          const bson_t *reply;
          bson_t *cmd = BCON_NEW ("find", "foo", "filter", "{", "}");
          mongoc_cursor_t *cursor = mongoc_collection_command (coll,
                                                               MONGOC_QUERY_NONE /* unused */,
                                                               0 /* unused */,
                                                               0 /* unused */,
                                                               0 /* unused */,
                                                               cmd,
                                                               NULL /* unused */,
                                                               NULL /* read prefs */);
          // Expect cursor to return exactly one document for the command reply.
          EXPECT (mongoc_cursor_next (cursor, &reply));

          bson_error_t error;
          if (mongoc_cursor_error (cursor, &error)) {
             FAIL ("Expected no error, got: %s\n", error.message);
          }

          // Expect successful reply to contain "ok": 1
          bson_iter_t iter;
          EXPECT (bson_iter_init_find (&iter, reply, "ok") && bson_iter_as_int64 (&iter) == 1);

          // Expect cursor to return no other documents.
          EXPECT (!mongoc_cursor_next (cursor, &reply));
          mongoc_cursor_destroy (cursor);
          bson_destroy (cmd);

       The above code block may be rewritten to use mongoc_collection_command_simple() instead, as shown below:

       After

          bson_t reply;
          bson_error_t error;
          bson_t *cmd = BCON_NEW ("find", "foo", "filter", "{", "}");
          if (!mongoc_collection_command_simple (coll, cmd, NULL /* read prefs */, &reply, &error)) {
             FAIL ("Expected no error, got: %s\n", error.message);
          }

          // Expect successful reply to contain "ok": 1
          bson_iter_t iter;
          EXPECT (bson_iter_init_find (&iter, &reply, "ok") && bson_iter_as_int64 (&iter) == 1);

          bson_destroy (&reply);
          bson_destroy (cmd);

RETURNS

       This function returns a newly allocated mongoc_cursor_t that should be freed with mongoc_cursor_destroy()
       when  no  longer  in  use.  The returned mongoc_cursor_t is never NULL, even on error. The user must call
       mongoc_cursor_next() on the returned mongoc_cursor_t to execute the initial command.

       Cursor errors can be checked with mongoc_cursor_error_document(). It always fills out the bson_error_t if
       an error occurred, and optionally includes a server reply document if the error occurred server-side.

       WARNING:
          Failure to handle the result of this function is a programming error.

AUTHOR

       MongoDB, Inc

COPYRIGHT

       2009-present, MongoDB, Inc.