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.\" 
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.\" under the terms of the GNU Free Documentation License, Version 1.3
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.TH "MONGOC_COLLECTION_COUNT" "3" "2016\(hy10\(hy12" "MongoDB C Driver"
.SH NAME
mongoc_collection_count() \- 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.
.SH "SYNOPSIS"

.nf
.nf
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);
.fi
.fi

.SH "PARAMETERS"

.TP
.B
collection
A
.B mongoc_collection_t
.
.LP
.TP
.B
flags
A
.B mongoc_query_flags_t
.
.LP
.TP
.B
query
A
.B bson_t
containing the query.
.LP
.TP
.B
skip
A int64_t, zero to ignore.
.LP
.TP
.B
limit
A int64_t, zero to ignore.
.LP
.TP
.B
read_prefs
A
.B mongoc_read_prefs_t
or
.B NULL
.
.LP
.TP
.B
error
An optional location for a
.B bson_error_t
or
.B NULL
.
.LP

.SH "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
.B query reference
at the MongoDB website.

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

.SH "ERRORS"

Errors are propagated via the
.B error
parameter.

.SH "RETURNS"

\(hy1 on failure, otherwise the number of documents counted.

.SH "EXAMPLE"

.nf
#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\en", error.message);
   } else {
      printf ("%"PRId64" documents counted.\en", count);
   }
}
.fi


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