bionic (3) mongoc_collection_count_with_opts.3.gz

NAME

       mongoc_collection_count_with_opts - mongoc_collection_count_with_opts()

SYNOPSIS

          int64_t
          mongoc_collection_count_with_opts (mongoc_collection_t *collection,
                                             mongoc_query_flags_t flags,
                                             const bson_t *query,
                                             int64_t skip,
                                             int64_t limit,
                                             const bson_t *opts,
                                             const mongoc_read_prefs_t *read_prefs,
                                             bson_error_t *error);

PARAMETERS

       • collection: A mongoc_collection_t.

       • flags: A mongoc_query_flags_t.

       • query: A bson_t containing the query.

       • skip: A int64_t, zero to ignore.

       • limit: A int64_t, zero to ignore.

       • opts: A bson_t, NULL to ignore.

       • read_prefs: An optional mongoc_read_prefs_t, otherwise uses the collection's read preference.

       • error: An optional location for a bson_error_t or NULL.

DESCRIPTION

       This  function  shall  execute  a  count  query  on  the underlying 'collection'. The bson 'query' is not
       validated, simply passed along as appropriate to the server.  As such, compatibility and errors should be
       validated in the appropriate server documentation.

       The  mongoc_read_concern_t  specified  on  the mongoc_collection_t will be used, if any. If read_prefs is
       NULL, the collection's read preferences are used.

       In addition to the standard functionality available from mongoc_collection_count,  this  function  allows
       the  user  to  add arbitrary extra keys to the count.  This pass through enables features such as hinting
       for counts.

       For more information, see the query reference at the MongoDB website.

ERRORS

       Errors are propagated via the error parameter.

RETURNS

       -1 on failure, otherwise the number of documents counted.

EXAMPLES

       Basic Counting.INDENT 0.0

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

          static void
          print_query_count (mongoc_collection_t *collection, bson_t *query)
          {
             bson_error_t error;
             int64_t count;
             bson_t opts;

             bson_init (&opts);
             BSON_APPEND_UTF8 (&opts, "hint", "_id_");

             count = mongoc_collection_count_with_opts (
                collection, MONGOC_QUERY_NONE, query, 0, 0, &opts, NULL, &error);

             bson_destroy (&opts);

             if (count < 0) {
                fprintf (stderr, "Count failed: %s\n", error.message);
             } else {
                printf ("%" PRId64 " documents counted.\n", count);
             }
          }
          #include <mongoc.h>
          #include <bcon.h>
          #include <stdio.h>

          static void
          print_query_count (mongoc_collection_t *collection, bson_t *query)
          {
             bson_t *selector;
             bson_t *opts;
             bson_error_t error;
             int64_t count;

             selector = BCON_NEW ("_id", "{", "$gt", BCON_UTF8 ("one"), "}");

             /* "One" normally sorts before "one"; make "one" come first */
             opts = BCON_NEW ("collation",
                              "{",
                              "locale",
                              BCON_UTF8 ("en_US"),
                              "caseFirst",
                              BCON_UTF8 ("lower"),
                              "}");

             count = mongoc_collection_count_with_opts (
                collection, MONGOC_QUERY_NONE, query, 0, 0, opts, NULL, &error);

             bson_destroy (selector);
             bson_destroy (opts);

             if (count < 0) {
                fprintf (stderr, "Count failed: %s\n", error.message);
             } else {
                printf ("%" PRId64 " documents counted.\n", count);
             }
          }

AUTHOR

       MongoDB, Inc

COPYRIGHT

       2018, MongoDB, Inc