mongoc_collection_update_one(3)

1MONGOC_COLLECTION_UPDATE_ONE(3)    libmongoc   MONGOC_COLLECTION_UPDATE_ONE(3)
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NAME

6       mongoc_collection_update_one - mongoc_collection_update_one()
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SYNOPSIS

9          bool
10          mongoc_collection_update_one (mongoc_collection_t *collection,
11                                        const bson_t *selector,
12                                        const bson_t *update,
13                                        const bson_t *opts,
14                                        bson_t *reply,
15                                        bson_error_t *error);
16

PARAMETERS

18       · collection: A mongoc_collection_t.
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20       · selector:  A  bson_t  containing  the query to match the document for
21         updating.
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23       · update: A bson_t containing the update to perform. If updating with a
24         pipeline, a bson_t array.
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26       · reply:  Optional.  An  uninitialized bson_t populated with the update
27         result, or NULL.
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29       · error: An optional location for a bson_error_t or NULL.
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31       opts may be NULL or a BSON document with additional command options:
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33       · writeConcern:  Construct  a  mongoc_write_concern_t  and   use   mon‐
34         goc_write_concern_append  to  add  the write concern to opts. See the
35         example code for mongoc_client_write_command_with_opts.
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37       · sessionId:  First,  construct  a  mongoc_client_session_t  with  mon‐
38         goc_client_start_session.  You  can  begin  a  transaction  with mon‐
39         goc_client_session_start_transaction, optionally with a mongoc_trans‐
40         action_opt_t  that  overrides  the options inherited from collection,
41         and use mongoc_client_session_append to add the session to opts.  See
42         the example code for mongoc_client_session_t.
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44       · validate:     Construct     a     bitwise-or     of    all    desired
45         bson_validate_flags_t. Set to false to skip client-side validation of
46         the provided BSON documents.
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48       · bypassDocumentValidation: Set to true to skip server-side schema val‐
49         idation of the provided BSON documents.
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51       · collation:  Configure  textual  comparisons.  See  Setting  Collation
52         Order,  and the MongoDB Manual entry on Collation. Collation requires
53         MongoDB 3.2 or later, otherwise an error is returned.
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55       · hint: A document or string that specifies the index to use to support
56         the query predicate.
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58       · upsert:  When true, creates a new document if no document matches the
59         query.
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61       · arrayFilters: An array of filters specifying to which array  elements
62         an update should apply.
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DESCRIPTION

65       This  function  updates at most one document in collection that matches
66       selector.
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68       To update multiple documents see mongoc_collection_update_many.
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70       If you pass a non-NULL reply, it is filled out  with  fields   matched‐
71       Count, modifiedCount, and optionally upsertedId if applicable. If there
72       is a server error then reply contains either a "writeErrors" array with
73       one  subdocument  or  a  "writeConcernErrors"  array. The reply must be
74       freed with bson_destroy().
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ERRORS

85       Errors are propagated via the error parameter.
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RETURNS

88       Returns  true  if successful. Returns false and sets error if there are
89       invalid arguments or a server or network error.
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91       A write concern timeout or write concern error is considered a failure.
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EXAMPLE

94       example-update.c.INDENT 0.0
95
96          #include "mongoc/mongoc.h"
97
98          int
99          main (int argc, char **argv)
100          {
101             bson_t *to_insert = BCON_NEW ("_id", BCON_INT32 (1));
102             bson_t *selector = BCON_NEW ("_id", "{", "$gt", BCON_INT32 (0), "}");
103             bson_t *update = BCON_NEW ("$set", "{", "x", BCON_INT32 (1), "}");
104             const bson_t *next_doc;
105             char *to_str;
106             bson_error_t error = {0};
107             mongoc_cursor_t *cursor;
108             mongoc_client_t *client;
109             mongoc_collection_t *coll;
110             const char *uri_string = "mongodb://localhost:27017/?appname=example-update";
111             mongoc_uri_t *uri = mongoc_uri_new_with_error (uri_string, &error);
112
113             if (!uri) {
114                fprintf (stderr,
115                         "failed to parse URI: %s\n"
116                         "error message:       %s\n",
117                         uri_string,
118                         error.message);
119                return EXIT_FAILURE;
120             }
121
122             client = mongoc_client_new_from_uri (uri);
123             if (!client) {
124                return EXIT_FAILURE;
125             }
126
127             coll = mongoc_client_get_collection (client, "db", "example_coll");
128
129             mongoc_client_set_error_api (client, 2);
130             /* insert a document */
131             if (!mongoc_collection_insert_one (coll, to_insert, NULL, NULL, &error)) {
132                fprintf (stderr, "insert failed: %s\n", error.message);
133                return EXIT_FAILURE;
134             }
135
136             if (!mongoc_collection_update_one (
137                    coll, selector, update, NULL, NULL, &error)) {
138                fprintf (stderr, "update failed: %s\n", error.message);
139                return EXIT_FAILURE;
140             }
141
142             to_str = bson_as_relaxed_extended_json (to_insert, NULL);
143             printf ("inserted: %s\n", to_str);
144             bson_free (to_str);
145
146             cursor = mongoc_collection_find_with_opts (coll, selector, NULL, NULL);
147             BSON_ASSERT (mongoc_cursor_next (cursor, &next_doc));
148             printf ("after update, collection has the following document:\n");
149
150             to_str = bson_as_relaxed_extended_json (next_doc, NULL);
151             printf ("%s\n", to_str);
152             bson_free (to_str);
153
154             BSON_ASSERT (mongoc_collection_drop (coll, NULL));
155
156             bson_destroy (to_insert);
157             bson_destroy (update);
158             bson_destroy (selector);
159             mongoc_collection_destroy (coll);
160             mongoc_uri_destroy (uri);
161             mongoc_client_destroy (client);
162
163             return EXIT_SUCCESS;
164          }
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AUTHOR

168       MongoDB, Inc
169

COPYRIGHT

171       2017-present, MongoDB, Inc
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1761.16.2                           Feb 25, 2020  MONGOC_COLLECTION_UPDATE_ONE(3)