复杂查询mongodb c

Question

我已经像这样创建了我的 mongodb 查询 >

 86     bson query[1];
 87     bson_init(query);
 88     bson_append_start_object(query, "service.virtual_mach    ine");
 89         bson_append_oid(query,"_id",result);
 90     bson_append_finish_object(query);
 91     bson_finish(query);

我用这个运行它>

 93     bson fields[1];
 94     bson_init(fields);
 95     bson_append_oid(fields, "_id", result);
 96     bson_finish(fields);
 97 
 98     mongo_cursor* cursor = NULL;
 99     cursor = mongo_find(conn, "db.services", query, field    s, 9999,0,0);

如果我打印“mongo_cursor_next(cursor)”方法，我得到一个“-1”(错误)，我想知道我的查询中有什么错误。

提前谢谢您。

Answer 1

这个？ https://github.com/mongodb/mongo-c-driver#error-handling

Most functions return MONGO_OK or BSON_OK on success and MONGO_ERROR or BSON_ERROR on failure. Specific error codes and error strings are then stored in the err and errstr fields of the mongo and bson objects. It is the client's responsibility to check for errors and handle them appropriately.