# mongoc_collection_count()

## Synopsis

    int64_t
    mongoc_collection_count (mongoc_collection_t       *collection,
                             mongoc_query_flags_t       flags,
                             const bson_t              *query,
                             int64_t                    skip,
                             int64_t                    limit,
                             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.
read_prefs | A mongoc_read_prefs_t or NULL.
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.

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.

## Example

### Count Example

    #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;

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

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