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指南

管理集合索引

要在MongoDB集合上创建索引，请使用 mongoc_collection_create_indexes_with_opts：

// `keys` represents an ascending index on field `x`.
bson_t *keys = BCON_NEW ("x", BCON_INT32 (1));
mongoc_index_model_t *im = mongoc_index_model_new (keys, NULL /* opts */);
if (mongoc_collection_create_indexes_with_opts (coll, &im, 1, NULL /* opts */, NULL /* reply */, &error)) {
   printf ("Successfully created index\n");
} else {
   bson_destroy (keys);
   HANDLE_ERROR ("Failed to create index: %s", error.message);
}
bson_destroy (keys);

要列出索引，请使用 mongoc_collection_find_indexes_with_opts：

mongoc_cursor_t *cursor = mongoc_collection_find_indexes_with_opts (coll, NULL /* opts */);
printf ("Listing indexes:\n");
const bson_t *got;
while (mongoc_cursor_next (cursor, &got)) {
   char *got_str = bson_as_canonical_extended_json (got, NULL);
   printf ("  %s\n", got_str);
   bson_free (got_str);
}
if (mongoc_cursor_error (cursor, &error)) {
   mongoc_cursor_destroy (cursor);
   HANDLE_ERROR ("Failed to list indexes: %s", error.message);
}
mongoc_cursor_destroy (cursor);

要删除索引，请使用 mongoc_collection_drop_index_with_opts 。可以使用keys mongoc_collection_keys_to_index_string 从 文档中获取索引名称：

bson_t *keys = BCON_NEW ("x", BCON_INT32 (1));
char *index_name = mongoc_collection_keys_to_index_string (keys);
if (mongoc_collection_drop_index_with_opts (coll, index_name, NULL /* opts */, &error)) {
   printf ("Successfully dropped index\n");
} else {
   bson_free (index_name);
   bson_destroy (keys);
   HANDLE_ERROR ("Failed to drop index: %s", error.message);
}
bson_free (index_name);
bson_destroy (keys);

有关完整示例，请参阅 example-manage-collection-indexes.c。

管理 Atlas Search 索引

要创建 Atlas Search 索引，请使用createSearchIndexes命令：

bson_t cmd;
// Create command.
{
   char *cmd_str = bson_strdup_printf (
      BSON_STR ({
         "createSearchIndexes" : "%s",
         "indexes" : [ {"definition" : {"mappings" : {"dynamic" : false}}, "name" : "test-index"} ]
      }),
      collname);
   ASSERT (bson_init_from_json (&cmd, cmd_str, -1, &error));
   bson_free (cmd_str);
}
if (!mongoc_collection_command_simple (coll, &cmd, NULL /* read_prefs */, NULL /* reply */, &error)) {
   bson_destroy (&cmd);
   HANDLE_ERROR ("Failed to run createSearchIndexes: %s", error.message);
}
printf ("Created index: \"test-index\"\n");
bson_destroy (&cmd);

要列出 Atlas Search 索引，请使用$listSearchIndexes聚合阶段：

const char *pipeline_str = BSON_STR ({"pipeline" : [ {"$listSearchIndexes" : {}} ]});
bson_t pipeline;
ASSERT (bson_init_from_json (&pipeline, pipeline_str, -1, &error));
mongoc_cursor_t *cursor =
   mongoc_collection_aggregate (coll, MONGOC_QUERY_NONE, &pipeline, NULL /* opts */, NULL /* read_prefs */);
printf ("Listing indexes:\n");
const bson_t *got;
while (mongoc_cursor_next (cursor, &got)) {
   char *got_str = bson_as_canonical_extended_json (got, NULL);
   printf ("  %s\n", got_str);
   bson_free (got_str);
}
if (mongoc_cursor_error (cursor, &error)) {
   bson_destroy (&pipeline);
   mongoc_cursor_destroy (cursor);
   HANDLE_ERROR ("Failed to run $listSearchIndexes: %s", error.message);
}
bson_destroy (&pipeline);
mongoc_cursor_destroy (cursor);

要更新 Atlas Search 索引，请使用updateSearchIndex命令：

bson_t cmd;
// Create command.
{
   char *cmd_str = bson_strdup_printf (
      BSON_STR (
         {"updateSearchIndex" : "%s", "definition" : {"mappings" : {"dynamic" : true}}, "name" : "test-index"}),
      collname);
   ASSERT (bson_init_from_json (&cmd, cmd_str, -1, &error));
   bson_free (cmd_str);
}
if (!mongoc_collection_command_simple (coll, &cmd, NULL /* read_prefs */, NULL /* reply */, &error)) {
   bson_destroy (&cmd);
   HANDLE_ERROR ("Failed to run updateSearchIndex: %s", error.message);
}
printf ("Updated index: \"test-index\"\n");
bson_destroy (&cmd);

要删除 Atlas Search 索引，请使用dropSearchIndex命令：

bson_t cmd;
// Create command.
{
   char *cmd_str = bson_strdup_printf (BSON_STR ({"dropSearchIndex" : "%s", "name" : "test-index"}), collname);
   ASSERT (bson_init_from_json (&cmd, cmd_str, -1, &error));
   bson_free (cmd_str);
}
if (!mongoc_collection_command_simple (coll, &cmd, NULL /* read_prefs */, NULL /* reply */, &error)) {
   bson_destroy (&cmd);
   HANDLE_ERROR ("Failed to run dropSearchIndex: %s", error.message);
}
printf ("Dropped index: \"test-index\"\n");
bson_destroy (&cmd);

有关完整示例，请参阅 example-manage-search-indexes.c。

后退

在 Microsoft Visual Studio 项目中使用 libmongoc