Search Results

Search found 9706 results on 389 pages for 'aggregate functions'.

Page 184/389 | < Previous Page | 180 181 182 183 184 185 186 187 188 189 190 191  | Next Page >

  • RTTI and Portability in C++

    - by Joshua
    If a compiler doesn't "support" RTTI, does that mean that the compiler can not handle class hierarchies that have virtual functions in them? Or have I been misunderstanding the literature about how RTTI isn't portable, and the issues lie elsewhere?

    Read the article

  • Determining if Memory Pointer is Valid - C++

    - by Jim Fell
    It has been my observation that if free( ptr ) is called where ptr is not a valid pointer to system-allocated memory, an access violation occurs. Let's say that I call free like this: LPVOID ptr = (LPVOID)0x12345678; free( ptr ); This will most definitely cause an access violation. Is there a way to test that the memory location pointed to by ptr is valid system-allocated memory? It seems to me that the the memory management part of the Windows OS kernel must know what memory has been allocated and what memory remains for allocation. Otherwise, how could it know if enough memory remains to satisfy a given request? (rhetorical) That said, it seems reasonable to conclude that there must be a function (or set of functions) that would allow a user to determine if a pointer is valid system-allocated memory. Perhaps Microsoft has not made these functions public. If Microsoft has not provided such an API, I can only presume that it was for an intentional and specific reason. Would providing such a hook into the system prose a significant threat to system security? Situation Report Although knowing whether a memory pointer is valid could be useful in many scenarios, this is my particular situation: I am writing a driver for a new piece of hardware that is to replace an existing piece of hardware that connects to the PC via USB. My mandate is to write the new driver such that calls to the existing API for the current driver will continue to work in the PC applications in which it is used. Thus the only required changes to existing applications is to load the appropriate driver DLL(s) at startup. The problem here is that the existing driver uses a callback to send received serial messages to the application; a pointer to allocated memory containing the message is passed from the driver to the application via the callback. It is then the responsibility of the application to call another driver API to free the memory by passing back the same pointer from the application to the driver. In this scenario the second API has no way to determine if the application has actually passed back a pointer to valid memory.

    Read the article

  • [NUnit+Moq] Guidelines for using Assert versus Verify

    - by emddudley
    I'm new to unit testing, and I'm learning how to use NUnit and Moq. NUnit provides Assert syntax for testing conditions in my unit tests, while Moq provides some Verify functions. To some extent these seem to provide the same functionality. How do I know when it's more appropriate to use Assert or Verify? Maybe Assert is better for confirming state, and Verify is better for confirming behavior (Classical versus Mockist)?

    Read the article

  • How to execute a program from file descriptor?

    - by stribika
    I need to execute a file when I only know the descriptor. It is also possible that there are no links to the file so finding out the name somehow is not an option. All the execve(), execvp(), etc functions take a file name. dlopen() also takes a name. Ugly solutions (like reading the file and calling some function pointer) are OK.

    Read the article

  • mySQL query: How to insert with UNION?

    - by Industrial
    Hi everybody, I am kind of new to mySQL:s union functions, at least when doing inserts with them. I have gotten the following to work based upon a example found on the net: INSERT INTO tableOne(a, b) SELECT a, $var FROM tableOne WHERE b = $var2 UNION ALL SELECT $var,$var Ok, nothing strange about that. But what happens when I want to insert a third value into the database that has nothing to do with the logic of the Select being done? Like : INSERT INTO tableOne(a, b, c ) How could that be done?

    Read the article

  • Need help/suggestions for creating fantasy sports scoring databases and queries

    - by MGumbel
    I'm trying to create a website for my friends and I to keep track of fantasy sports scoring. So far, I've been doing the calculations and storage in Excel, which is very tedious. I'm trying to make it more simplified and automated through a SQL database that I can then wrap a web app around to enter daily stat updates. It's premised on our participation in another commercial site where we trade virtual shares of athletes, and thus acquire an "ownership percentage" in each athlete. For instance, if there are 100 shares of AROD, and I own 10 shares, then I own 10%. It then applies this to traditional baseball rotisserie scoring. So, for instance, if AROD has 1 HR today, then his adjusted HR stat would be 1.10. If he also has 2 RBI's, then his adjusted RBI stat today would be 2.20, based on (2 x 1.10)(1 to normalize the stat, and the .10 to represent the ownership percentage). All the stats for my team would then be summed each day and added to my stat history to come to an aggregated total. After that, points are allocated based on the ranking of each participant in each category at the end of the day. E.g. if there are 10 participants, and I have the highest total aggregate number of Adjusted HR's, then I get 10 pts. The points are then summed across the different stat categories to come up with a total point ranking for that day. An added difficulty is that ownership %'s can change on a daily basis. So far, in playing around with different schema, I don't know that having a separate table for each athlete's stats and each player's ownership %'s is the wisest choice. It seems to me that simply having two tables, one that contains the daily stat information for each athlete, and another that shows the ownership % of each player. My friend suggested using a start and end date for each ownership % to represent the potential daily changes in this category. I'm admittedly new to database development, so any suggestions on query code would be appreciated.

    Read the article

  • 64-bit integers in Cython

    - by Homayoon
    I'm trying to interface a C++ library (pHash) with Python using Cython, but I have trouble with some of the types. The library functions use "unsigned long long" and I can't find a way to declare variables and parameters with this type. I searched for a list of the types that I can use with cdef but I found nothing. Can anyone point me to such a list (if it exists) or otherwise suggest a way to use 64 bit types in Cython? Thanks.

    Read the article

  • Automatic profiling visual studio 2008

    - by phil
    Is there a way to do automatic profiling in visual studio 2008? I know how the profiling works both from the command line and using the GUI in VS08. What I want to accomplish: After my nightly build I want to complete some profiling (instrumental) to see if some functions (will most likely always be the same) have changed in some negative way (or positive of course).

    Read the article

  • how wordpress can un-slug a title

    - by Mac Taylor
    i still , don't understand , how wordpress can understand what is this url refer to : www.mysite.com/about-me/ they are using no identifier if they using slug functions so how they can retain story information or in other word , how they change back the slugged title to select from database

    Read the article

  • Where does abort() and terminate() "live"?

    - by user325016
    Regarding the terminate handler, As i understand it, when something bad happens in code, for example when we dont catch an exception, terminate() is called, which in turn calls abort() set_terminate(my_function) allows us to get terminate() to call a user specified function my_terminate. my question is: where do these functions "live" they don't seem to be a part of the language, but work as if they are present in every single cpp file, without having to include any header file.

    Read the article

  • deep or shallow copying?

    - by Dervin Thunk
    Dear all. I was wondering if there are examples of situations where you would purposefully pass an argument by value (deep copy) in C. For instance, passing a char to a function is usually cheaper in space than passing a char* (if there's no need to share the value), since char is 1 byte and pointers are, well, whatever they are in the architecture (4 in my 32 bit machine). ?(When) do you want to pass (big) deep copies to functions? if so, why?

    Read the article

  • Classes. Whats the point?

    - by Ben Shelock
    I'm fairly new to OOP in PHP, I've made a couple of basic scripts but nothing impressive. All I've really taken from it is that it would probably be easier just make a collection of functions and include them. The structure of classes seems to just confuse what was otherwise a simple process. And in collating everything into a class it doesn't really add any functionality. So I'm clearly missing something. Could someone explain what functionality is added by creating classes

    Read the article

  • Entity Sql Group By problem, please help

    - by Zviadi
    Hello, help me please with this simple E-sql query: var qStr = "SELECT SqlServer.Month(o.DatePaid) as month, SqlServer.Sum(o.PaidMoney) as PaidMoney FROM XACCModel.OrdersIncomes as o group by SqlServer.Month(o.DatePaid)"; heres what I have. I have simple Entity called OrdersIncomes with ID,PaidMoney,DatePaid,Order_ID properties I want to select Month and Summed PaidMoney like this: month Paidmoney 1 500 2 700 3 1200 T-SQL looks like this and works fine: select MONTH(o.DatePaid), SUM(o.PaidMoney) from OrdersIncomes as o group by MONTH(o.DatePaid) results: 3 31.0000 4 127.0000 5 20.0000 (3 row(s) affected) but E-SQL doesnot work and I dont know what to do. here my E-SQL which needs refactoring: var qStr = "SELECT SqlServer.Month(o.DatePaid) as month, SqlServer.Sum(o.PaidMoney) as PaidMoney FROM XACCModel.OrdersIncomes as o group by SqlServer.Month(o.DatePaid)"; theres exception: ErrorDescription = "The identifier 'o' is not valid because it is not contained either in an aggregate function or in the GROUP BY clause." if I include o in group by clause, like: FROM XACCModel.OrdersIncomes as o group by o then I dont get summed and agregated results. is this some bug? or what Im doing wrong. heres Linq to Entities query and it works too: var incomeResult = from ic in _context.OrdersIncomes group ic by ic.DatePaid.Month into gr select new { Month = gr.Key, PaidMoney = gr.Sum(i = i.PaidMoney) };

    Read the article

  • making multiple c# file for one asp.net page

    - by Nikhil K
    For my project(in asp.net) i wrote near 1000 lines of c# code for one asp.net page.It includes so many functions.The problem is,it is going complicated while i am writing more codes on one page.How can i make multiple c# files for one asp.net page?? I tried by adding new class in VS2008.But calling a function from one file to other is making error(item is not present in current file).How can i do that??

    Read the article

  • Qt - serialize/deserialaize text plus picture

    - by Narek
    I want to use a field (kind of QTextEdit), which is capabale of storing picture and text (like MS Word is doing) and it serializes and deserialaizes picture+text data. Is there any Qt Widget that allows us to manipulate with picture and text simultaniously and it has set/get functions which operate with serializable type? In othger words, I want to know if there exsists any Qt widget that can store picture+text and has "get" types of function that returns the content of that widgets editable area, which is a Type that could be serialized with QDataStream.

    Read the article

  • having trouble with zooming in android webview

    - by Talha
    I'm new to android. I'm using webview in scrollview to display my local html page (html has text only). I created two buttons for zoomin and zoomout using behind function zoomIn() & zoomOut() respectively. These functions work fine. The problenm is, when I zoom in, some of the text goes out from both top and bottom and it doesn't appear when I scroll. How can I resolve this?

    Read the article

  • c++ recursion with arrays

    - by Sam
    I have this project that I'm working on for a class, and I'm not looking for the answer, but maybe just a few tips since I don't feel like I'm using true recursion. The problem involves solving the game of Hi Q or "peg solitaire" where you want the end result to be one peg remaining (it's played with a triangular board and one space is open at the start.) I've represented the board with a simple array, each index being a spot and having a value of 1 if it has a peg, and 0 if it doesn't and also the set of valid moves with a 2 dimensional array that is 36, 3 (each move set contains 3 numbers; the peg you're moving, the peg it hops over, and the destination index.) So my problem is that in my recursive function, I'm using a lot of iteration to determine things like which space is open (or has a value of 0) and which move to use based on which space is open by looping through the arrays. Secondly, I don't understand how you would then backtrack with recursion, in the event that an incorrect move was made and you wanted to take that move back in order to choose a different one. This is what I have so far; the "a" array represents the board, the "b" array represents the moves, and the "c" array was my idea of a reminder as to which moves I used already. The functions used are helper functions that basically just loop through the arrays to find an empty space and corresponding move. : void solveGame(int a[15], int b[36][3], int c[15][3]){ int empSpace; int moveIndex; int count = 0; if(pegCount(a) < 2){ return; } else{ empSpace = findEmpty(a); moveIndex = chooseMove( a, b, empSpace); a[b[moveIndex][0]] = 0; a[b[moveIndex][1]] = 0; a[b[moveIndex][2]] = 1; c[count][0] = b[moveIndex][0]; c[count][1] = b[moveIndex][1]; c[count][2] = b[moveIndex][2]; solveGame(a,b,c); } }

    Read the article

  • How do I prevent use of beta classes from google guava library?

    - by mjlee
    We have been using Google collections in the production for several months. We would like to start using guava for additional functions. However, I'm afraid to bring guava into our product stack b/c some developers may start to use 'beta' classes. We have various unit-tests in our code but at this point, I prefer not to include 'beta' class b/c it is subject to change in the future. Is there any easy way to do detect if the project includes any 'beta' guava classes?

    Read the article

  • JNA problem with char** (in dll)

    - by underline
    Hi, ok it is 'easy' to make jna wrapper solution for mapping exported functions within dll using jna: long f1(int x), just int long f2(char* y), just char[] but how to deal with long f3(char** z) ? I need f3's result(long) as well as z value on java side. Please don't say cpp code should be rewritten to avoid this:-)

    Read the article

< Previous Page | 180 181 182 183 184 185 186 187 188 189 190 191  | Next Page >