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MONGOC_CLIENT_COMMAND(3) libmongoc MONGOC_CLIENT_COMMAND(3)

WARNING:

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



SYNOPSIS

mongoc_cursor_t *
mongoc_client_command (mongoc_client_t *client,


                       const char *db_name,


                       mongoc_query_flags_t flags,


                       uint32_t skip,


                       uint32_t limit,


                       uint32_t batch_size,


                       const bson_t *query,


                       const bson_t *fields,


                       const mongoc_read_prefs_t *read_prefs);


This function is not considered a retryable read operation.

DESCRIPTION

This function creates a cursor which will execute the command when mongoc_cursor_next() is called on it. The client's read preference, read concern, and write concern are not applied to the command, and mongoc_cursor_next() will not check the server response for a write concern error or write concern timeout.

If mongoc_cursor_next() returns false, then retrieve error details with mongoc_cursor_error() or mongoc_cursor_error_document().

PARAMETERS

  • client: A mongoc_client_t.
  • db_name: The name of the database to run the command on.
  • flags: Unused.
  • skip: Unused.
  • limit: Unused.
  • batch_size: Unused.
  • query: A bson_t containing the command specification.
  • fields: Unused.
  • read_prefs: An optional mongoc_read_prefs_t. Otherwise, the command uses mode MONGOC_READ_PRIMARY.

MIGRATING

mongoc_client_command() is deprecated.

The following example uses mongoc_client_command():

Before

const bson_t *reply;
bson_t *cmd = BCON_NEW ("find", "foo", "filter", "{", "}");
mongoc_cursor_t *cursor = mongoc_client_command (client,


                                                 "db",


                                                 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_client_command_simple() instead, as shown below:

After

bson_t reply;
bson_error_t error;
bson_t *cmd = BCON_NEW ("find", "foo", "filter", "{", "}");
if (!mongoc_client_command_simple (client, "db", 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

A mongoc_cursor_t.

The cursor should be freed with mongoc_cursor_destroy().

AUTHOR

MongoDB, Inc

COPYRIGHT

2009-present, MongoDB, Inc.

January 9, 2025 1.29.2