1MONGOC_COLLECTION_COUNT(3)         libmongoc        MONGOC_COLLECTION_COUNT(3)
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NAME

6       mongoc_collection_count - mongoc_collection_count()
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DEPRECATED

9       This  function  is  deprecated and should not be used in new code.  Use
10       mongoc_collection_count_documents or  mongoc_collection_estimated_docu‐
11       ment_count instead.
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13       mongoc_collection_count_documents  has  similar  performance to calling
14       mongoc_collection_count with a non-NULL query,  and  is  guaranteed  to
15       retrieve  an  accurate  collection count. See migrating from deprecated
16       count functions for details.
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18       mongoc_collection_estimated_document_count has the same performance  as
19       calling  mongoc_collection_count  with a NULL query, but is not guaran‐
20       teed to retrieve an accurate collection count.
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22       This function is considered a retryable read operation.  Upon  a  tran‐
23       sient error (a network error, errors due to replica set failover, etc.)
24       the operation is safely retried once.  If retryreads is  false  in  the
25       URI (see mongoc_uri_t) the retry behavior does not apply.
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SYNOPSIS

28          int64_t
29          mongoc_collection_count (mongoc_collection_t *collection,
30                                   mongoc_query_flags_t flags,
31                                   const bson_t *query,
32                                   int64_t skip,
33                                   int64_t limit,
34                                   const mongoc_read_prefs_t *read_prefs,
35                                   bson_error_t *error)
36           BSON_GNUC_DEPRECATED_FOR (mongoc_collection_count_documents or
37                                     mongoc_collection_estimated_document_count);
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PARAMETERS

40       · collection: A mongoc_collection_t.
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42       · flags: A mongoc_query_flags_t.
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44       · query: A bson_t containing the query.
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46       · skip: A int64_t, zero to ignore.
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48       · limit: A int64_t, zero to ignore.
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50       · read_prefs: A mongoc_read_prefs_t or NULL.
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52       · error: An optional location for a bson_error_t or NULL.
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DESCRIPTION

55       This  function  shall  execute a count query on the underlying 'collec‐
56       tion'. The bson 'query' is not validated, simply passed along as appro‐
57       priate to the server.  As such, compatibility and errors should be val‐
58       idated in the appropriate server documentation.
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60       For more information, see the query reference at the MongoDB website.
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62       The mongoc_read_concern_t specified on the mongoc_collection_t will  be
63       used,  if any. If read_prefs is NULL, the collection's read preferences
64       are used.
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ERRORS

67       Errors are propagated via the error parameter.
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RETURNS

70       -1 on failure, otherwise the number of documents counted.
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EXAMPLE

73          #include <bson/bson.h>
74          #include <mongoc/mongoc.h>
75          #include <stdio.h>
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77          static void
78          print_query_count (mongoc_collection_t *collection, bson_t *query)
79          {
80             bson_error_t error;
81             int64_t count;
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83             count = mongoc_collection_count (
84                collection, MONGOC_QUERY_NONE, query, 0, 0, NULL, &error);
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86             if (count < 0) {
87                fprintf (stderr, "Count failed: %s\n", error.message);
88             } else {
89                printf ("%" PRId64 " documents counted.\n", count);
90             }
91          }
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AUTHOR

94       MongoDB, Inc
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97       2017-present, MongoDB, Inc
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1021.16.2                           Feb 25, 2020       MONGOC_COLLECTION_COUNT(3)
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