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• EF4 querying through the generations

  - by Hans Kesting

  I have a model withs Parents, Children and Grandchildren, in a many-to-many relationship. Using this article I created POCO classes that work fine, except for one thing I can't yet figure out. When I query the Parents or Children directly using LINQ, the SQL reflects the LINQ query (a .Count() executes a COUNT in the database and so on) - fine. The Parent class has a Children property, to access it's children. But (and now for the problem) this doesn't expose an IQueryable interface but an ICollection. So when I access the Children property on a particular parent all the Parent's Children are read. Even worse, when I access the Grandchildren (theParent.Children.SelectMany(child => child.GrandChildren).Count()) then for each and every child a separate request is issued to select it's grandchildren. Changing the type of the Children property from ICollection to IQueryable doesn't solve this. Apart from missing needed methods like Add() and Remove(), EF just doesn't recognize the property then. Are there correct ways (as in: low database interaction) of querying through children (and what are they)? Or is this just not possible?

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• Architecture of finding movable geotagged objects

  - by itsme

  I currently have a Postgres DB filled with approx. 300.000 data-sets of moving vehicles all over the world. My very frequently repeated query is: Give me all vehicles in a 5/10/20mile radius. Currently I spend around 600 to 1200 ms in the DB to prepare the set of located vehicle-objects. I am looking to vastly improve this time by ideally one or two orders of magnitude if possible. I am working in a Ruby on Rails 3.0beta environment if this is relevant. Any ideas how to architect the whole system to accelerate this query? Any NoSQL database able to deliver this kind of geolocation performance? I know of MongoDB working on an extension to facilitate this scenario but haven't tried it yet. Any intelligent use of Redis to achieve this? One problem with SQL-DBs here seems to be that I can't possibly use indexes because my vehicles are mostly moving around, meaning I had to constantly created DB indexes which, by itself, is probably more expensive than just doing the searching without index. Looking forward to your thoughs, Thanks!

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• Create an index only on certain rows in mysql

  - by dhruvbird

  So, I have this funny requirement of creating an index on a table only on a certain set of rows. This is what my table looks like: USER: userid, friendid, created, blah0, blah1, ..., blahN Now, I'd like to create an index on: (userid, friendid, created) but only on those rows where userid = friendid. The reason being that this index is only going to be used to satisfy queries where the WHERE clause contains "userid = friendid". There will be many rows where this is NOT the case, and I really don't want to waste all that extra space on the index. Another option would be to create a table (query table) which is populated on insert/update of this table and create a trigger to do so, but again I am guessing an index on that table would mean that the data would be stored twice. How does mysql store Primary Keys? I mean is the table ordered on the Primary Key or is it ordered by insert order and the PK is like a normal unique index? I checked up on clustered indexes (http://dev.mysql.com/doc/refman/5.0/en/innodb-index-types.html), but it seems only InnoDB supports them. I am using MyISAM (I mention this because then I could have created a clustered index on these 3 fields in the query table). I am basically looking for something like this: ALTER TABLE USERS ADD INDEX (userid, friendid, created) WHERE userid=friendid

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• How grouping and totaling are done into three tables using JOIN

  - by text

  Here are my tables respondents: field sample value respondentid : 1 age : 2 gender : male survey_questions: id : 1 question : Q1 answer : sample answer answers: respondentid : 1 question : Q1 answer : 1 --id of survey question I want to display all respondents who answered the certain survey, display all answers and total all the answer and group them according to the age bracket. I tried using this query: $sql = "SELECT res.Age, res.Gender, answer.id, answer.respondentid, SUM(CASE WHEN res.Gender='Male' THEN 1 else 0 END) AS males, SUM(CASE WHEN res.Gender='Female' THEN 1 else 0 END) AS females, CASE WHEN res.Age < 1 THEN 'age1' WHEN res.Age BETWEEN 1 AND 4 THEN 'age2' WHEN res.Age BETWEEN 4 AND 9 THEN 'age3' WHEN res.Age BETWEEN 10 AND 14 THEN 'age4' WHEN res.Age BETWEEN 15 AND 19 THEN 'age5' WHEN res.Age BETWEEN 20 AND 29 THEN 'age6' WHEN res.Age BETWEEN 30 AND 39 THEN 'age7' WHEN res.Age BETWEEN 40 AND 49 THEN 'age8' ELSE 'age9' END AS ageband FROM Respondents AS res INNER JOIN Answers as answer ON answer.respondentid=res.respondentid INNER JOIN Questions as question ON answer.Answer=question.id WHERE answer.Question='Q1' GROUP BY ageband ORDER BY res.Age ASC"; I was able to get the data but the listing of all answers are not present. What's wrong with my query. I want to produce something like this: ex: # of Respondents is 3 ages: 2,3 and 6 Question: what are your favorite subjects? Ages 1-4: subject 1: 1 subject 2: 2 subject 3: 2 total respondents for ages 1-4 : 2 Ages 5-10: subject 1: 1 subject 2: 1 subject 3: 0 total respondents for ages 5-10 : 1

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• When to use CTEs to encapsulate sub-results, and when to let the RDBMS worry about massive joins.

  - by IanC

  This is a SQL theory question. I can provide an example, but I don't think it's needed to make my point. Anyone experienced with SQL will immediately know what I'm talking about. Usually we use joins to minimize the number of records due to matching the left and right rows. However, under certain conditions, joining tables cause a multiplication of results where the result is all permutations of the left and right records. I have a database which has 3 or 4 such joins. This turns what would be a few records into a multitude. My concern is that the tables will be large in production, so the number of these joined rows will be immense. Further, heavy math is performed on each row, and the idea of performing math on duplicate rows is enough to make anyone shudder. I have two questions. The first is, is this something I should care about, or will SQL Server intelligently realize these rows are all duplicates and optimize all processing accordingly? The second is, is there any advantage to grouping each part of the query so as to get only the distinct values going into the next part of the query, using something like: WITH t1 AS ( SELECT DISTINCT... [or GROUP BY] ), t2 AS ( SELECT DISTINCT... ), t3 AS ( SELECT DISTINCT... ) SELECT... I have often seen the use of DISTINCT applied to subqueries. There is obviously a reason for doing this. However, I'm talking about something a little different and perhaps more subtle and tricky.

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• UNMOUNTABLE BOOT VOLUME win7

  - by user1809318

  i'm having a serious problem with my laptop (Toshiba satellite l40). Two days ago i just turned it off by holding the power button and the next day it didn't start at all. There is a blue screen with an error : UNMOUNTABLE BOOT VOLUME, i searched all over the net for a solution, did almost everything like using the windows 7 install disk and trying to repair with the command prompt (check c: /r, bootfix etc.) it runs the check saying there are no errors and when i restart the blue screen again. Can someone please give me some new solution?

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• ubuntu 10.04 span window across workspaces

  - by jakerman999

  I'm using an old server machine as a linux box desktop, and as such I have a lot of power but not a lot of display options. I cannot increase my resolution past 800x600 and recently this has become just to small. I have mostly been able to workaround windows being to large for a workspace by moving them with the alt key, but I would like to use something a little more versatile. My plan is to have a setup where I can open a windows (say firefox) on the top-left workspace and then resize it so that it fills four workspaces in an emulated "wall of monitors" fashion. I already have my workspaces arranged like this, but I am not seeing any options for allowing programs/windows to exist on more than one workspace at a time, I know that what I am trying to accomplish is possible (or was at some point in time) because when I google my solution pages appear with people trying to do the opposite (windows already appear on more than one workspace and they dislike it). Any help is much appreciated.

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• Translate an IQueryable instance to LINQ syntax in a string

  - by James Dunne

  I would like to find out if anyone has existing work surrounding formatting an IQueryable instance back into a LINQ C# syntax inside a string. It'd be a nice-to-have feature for an internal LINQ-to-SQL auditing framework I'm building. Once my framework gets the IQueryable instance from a data repository method, I'd like to output something like: This LINQ query: from ce in db.EiClassEnrollment join c in db.EiCourse on ce.CourseID equals c.CourseID join cl in db.EiClass on ce.ClassID equals cl.ClassID join t in db.EiTerm on ce.TermID equals t.TermID join st in db.EiStaff on cl.Instructor equals st.StaffID where (ce.StudentID == studentID) && (ce.TermID == termID) && (cl.Campus == campusID) select new { ce, cl, t, c, st }; Generates the following LINQ-to-SQL query: DECLARE @p0 int; DECLARE @p1 int; DECLARE @p2 int; SET @p0 = 777; SET @p1 = 778; SET @p2 = 779; SELECT [t0].[ClassEnrollmentID], ..., [t4].[Name] FROM [dbo].[ei_ClassEnrollment] AS [t0] INNER JOIN [dbo].[ei_Course] AS [t1] ON [t0].[CourseID] = [t1].[CourseID] INNER JOIN [dbo].[ei_Class] AS [t2] ON [t0].[ClassID] = [t2].[ClassID] INNER JOIN [dbo].[ei_Term] AS [t3] ON [t0].[TermID] = [t3].[TermID] INNER JOIN [dbo].[ei_Staff] AS [t4] ON [t2].[Instructor] = [t4].[StaffID] WHERE ([t0].[StudentID] = @p0) AND ([t0].[TermID] = @p1) AND ([t2].[Campus] = @p2) I already have the SQL output working as you can see. I just need to find a way to get the IQueryable to translate into a string representing its original LINQ syntax (with an acceptable translation loss). I'm not afraid of writing it myself, but I'd like to see if anyone else has done this first.

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• What constitutes explicit creation of entities in LINQ to SQL? What elegant "solutions" are there to

  - by Marcelo Zabani

  Hi SO, I've been having problems with the rather famous "Explicit construction of entity type '##' in query is not allowed." error. Now, for what I understand, this exists because if explicit construction of these objects were allowed, tracking changes to the database would be very complicated. So I ask: What constitutes the explicit creation of these objects? In other terms: Why can I do this: Product foo = new Product(); foo.productName = "Something"; But can't do this: var bar = (from item in myDataContext.Products select new Product { productName = item.productName }).ToList(); I think that when running the LINQ query, some kind of association is made between the objects selected and the table rows retrieved (and this is why newing a Product in the first snippet of code is no problem at all, because no associations were made). I, however, would like to understand this a little more in depth (and this is my first question to you, that is: what is the difference from one snippet of code to another). Now, I've heard of a few ways to attack this problem: 1) The creation of a class that inherits the linq class (or one that has the same properties) 2) Selecting anonymous objects And this leads me to my second question: If you chose one of the the two approaches above, which one did you choose and why? What other problems did your approach introduce? Are there any other approaches?

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• PHP cookies in a session handler

  - by steve

  I have run into a very interesting problem trying to debug my custom php session handler. For some reason unknown to me I can set cookies all the way through the session handler right up until the very start of the write function. As far as I know session handler calls go in this order. open - read - write - close The open function sets a cookie just fine. function open($save_path,$session_name) { require_once('database.php'); require_once('websiteinfo.php'); mysql_connect($sqllocation,$sql_session_user,$sql_session_pass); @mysql_select_db($sql_default_db); date_default_timezone_set('America/Los_Angeles'); setcookie("test","test"); return TRUE; } The read function can set a cookie right up until the very moment it returns a value. function read($session_id) { $time = time(); $query = "SELECT * FROM 'sessions' WHERE 'expires' > '$time'"; $query_result = mysql_query($query); $data = ''; /* fetch the array and start sifting through it */ while($session_array = mysql_fetch_array($query_result)) { /* strip the slashes from the session array */ $session_array = $this->strip($session_array); /* authenticate the user and if so return the session data */ if($this->auth_check($session_array,$session_id)) { $data = $session_array['data']; } } setcookie("testcookie1","value1",time()+1000,'/'); return $data; } The very first line of the write function is setting another cookie and it cannot because the headers are already sent. Any ideas anyone? Thanks in advance

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• Creating a new PC, need suggestions on parts [closed]

  - by zilentworld

  I want to build a new PC and went around PC Stores to ask for quotations with only some parts that i want and the rest are filled up by them. Here is the "best" i got Core i5 3550 4gb ram ddr3 (planning to get 8,no brand yet) 500gb hdd (no brand yet) GTX550Ti 1g DDR5 Asus P8H61 ATX Casing Here is what i have from my last PC: Huntkey green power 500w Hyper TX3 Evo I want a dual monitor pc which will be used mostly for gaming,programming and i do a lot of multitasking. Im not planning YET to OC my cpu but i will in the near future. So can i ask for suggestions on what to change on my list? my budget is about 800$ (including 2nd monitor)

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• Return the Column Name for row with last non-null value "Ms Access 2007"

  - by bri1969

  I have a Table, which contains a list of league players. Each season, we record their Points per Dart. Their total PPD for that season is stored in other tables and extracted through other queries, which in turn are imported to the master table "Player History" at the end of the season for use as historical data. The current query retrieves each players PPD for each season they played, when they played last, and how many seasons played. The code for Last season Played has become too long and unstable to use. it was originally created, and split into two separate columns because a single SQL was to long. (LSP1) and LSP2) which work, but as I add seasons, Access does not like the length of code. In short, i need to find a more simple code that will look at each row, and look in that row for the last non null cell and report which column that last non null value is in. So if a player played seasons 30 & 31, but did not play 32..but did play 33, the Column with the code should be titled Last Season Played, and for that Player, it would state "33" in that cell, indicating that this player last played season "33" I will provide both tables and the query.. Please help

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• dell E6500 laptop will not hibernate/standby

  - by Mark Schultheiss

  I am using a Dell E6500 laptop with windows XP on it, it was originally tagged/installed with Windows Vista. My issue is, when I close the lid, it will not either Hibernate or Standby. If I close the lid with either of these options, I then have to startup from scratch, and anything I had open is not open. I just want to close the lid, have it keep what I have running, not use power util I open the lid again and start it up (with the stuff still open I had open of course). Suggestions?

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• sqlobject: No connection has been defined for this thread or process

  - by Claudiu

  I'm using sqlobject in Python. I connect to the database with conn = connectionForURI(connStr) conn.makeConnection() This succeeds, and I can do queries on the connection: g_conn = conn.getConnection() cur = g_conn.cursor() cur.execute(query) res = cur.fetchall() This works as intended. However, I also defined some classes, e.g: class User(SQLObject): class sqlmeta: table = "gui_user" username = StringCol(length=16, alternateID=True) password = StringCol(length=16) balance = FloatCol(default=0) When I try to do a query using the class: User.selectBy(username="foo") I get an exception: ... File "c:\python25\lib\site-packages\SQLObject-0.12.4-py2.5.egg\sqlobject\main.py", line 1371, in selectBy conn = connection or cls._connection File "c:\python25\lib\site-packages\SQLObject-0.12.4-py2.5.egg\sqlobject\dbconnection.py", line 837, in __get__ return self.getConnection() File "c:\python25\lib\site-packages\SQLObject-0.12.4-py2.5.egg\sqlobject\dbconnection.py", line 850, in getConnection "No connection has been defined for this thread " AttributeError: No connection has been defined for this thread or process How do I define a connection for a thread? I just realized I can pass in a connection keyword which I can give conn to to make it work, but how do I get it to work if I weren't to do that?

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• Need help with jquery json data transfer from php file

  - by Scarface

  Hey guys I am trying to return the latest 10 results of a query from a php file, through json format, to a jquery getjson function that prints results. I am getting weird problems though. For example I am only getting 8 entries returned, and some are disordered, and sometimes nothing is returned. I am not really sure what I am doing wrong, so if anyone has any ideas I would really appreciate it. This is my query ($res) SELECT time, user, message FROM comments WHERE topic_id='$topic_id' ORDER BY time DESC LIMIT 10 This is the processing of the results while($row = mysql_fetch_array($res)){ $message=$row['message']; $user=$row['user']; if($row['message'] AND $row['time'] > $_GET['time']) $data[] = $row; } $out = json_encode($data); print $out; And this is the retrieval where prepare is just a function that returns information into a div $.getJSON(files+"processing.php?action=load&time="+0+"&topic_id="+topic_id+"&t=" + (new Date()), function(json) { if(json.length) { for(i=0; i < 10; i++) { $('#comment-list').prepend(prepare(json[i])); $('#list-' + count).fadeIn(1500); } } }); function prepare(response) { count++; var string = '<li class="comment-list" id="list-'+count+'">' //organize info into a div +'</li>'; return string; }

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• How can I integrate advanced computations into a database field?

  - by ciclistadan

  My biological research involves the measurement of a cellular structure as it changes length throughout the course of observation (capturing images every minute for several hours). As my data sets have become larger I am trying to store them in an Access database, from which I would like to perform various queries about their changes in size. I know that the SELECT statement can incorporate some mathematical permutations, but I have been unable to incorporate many of my necessary calculations (probably due to my lack of knowledge). For example, one calculation involves determining the rate of change during specifically defined periods of growth. This calculation is entirely dependent on the raw data saved in the table, therefore I didn't this it would be appropriate to just calculate it in excel prior to entry into the field. So my question is, what would be the most appropriate method of performing this calculation. Should I attempt to string together a huge SELECT calculation in my QUERY, or is there a way to use another language (I know perl?) which can be called to populate the new query field? I'm not looking for someone to write the code, just where is it appropriate to incorporate each step. Also, I am currently using Office Access but would be interested in any mySQL answers as I may be moving to this platform at a later date. Thanks all!

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• Programming Practice

  - by deepti

  public DataTable UserUpdateTempSettings(int install_id, int install_map_id, string Setting_value,string LogFile) { SqlConnection oConnection = new SqlConnection(sConnectionString); DataSet oDataset = new DataSet(); DataTable oDatatable = new DataTable(); SqlDataAdapter MyDataAdapter = new SqlDataAdapter(); try { oConnection.Open(); cmd = new SqlCommand("SP_HOTDOC_PRINTTEMPLATE_PERMISSION", oConnection); cmd.Parameters.Add(new SqlParameter ("@INSTALL_ID", install_id)); cmd.Parameters.Add(new SqlParameter ("@INSTALL_MAP_ID", install_map_id)); cmd.Parameters.Add(new SqlParameter("@SETTING_VALUE", Setting_value)); if (LogFile != "") { cmd.Parameters.Add(new SqlParameter("@LOGFILE",LogFile)); } cmd.CommandType = CommandType.StoredProcedure; MyDataAdapter.SelectCommand = cmd; cmd.ExecuteNonQuery(); MyDataAdapter.Fill(oDataset); oDatatable = oDataset.Tables[0]; return oDatatable; } catch (Exception ex) { Utils.ShowError(ex.Message); return oDatatable; } finally { if ((oConnection.State != ConnectionState.Closed) || (oConnection.State != ConnectionState.Broken)) { oConnection.Close(); } oDataset = null; oDatatable = null; oConnection.Dispose(); oConnection = null; } } i have used execute non query.. normally its not used with data adapter... if iam not using its giving me error.. is it bad programming practice to use execute non query with data adapter

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• Features of Emacs that are complementary to Vim?

  - by redacted

  I've been using Vim extensively for a while now, and I really enjoy working with it. However, I keep reading praises for Emacs. I've decided to take a look at Emacs to round out my knowledge of the Unix editors (not to mention Emacs keybindings are used extensively). But! I'm happy doing most of my daily work in Vim. So ideally what I'd like is to look at (apart from basics) are the gaps that Emacs can fill, or things that it can just do better than Vim. I suppose the canonical example is Lisp/Scheme coding in Emacs versus Vim. Where would you start tinkering with Emacs to really appreciate its power, and to get a good idea of how its approach to editing differs from Vim, and how the editors can complement each other? What would be a good introduction in the same vein?

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• Java - multithreaded access to a local value store which is periodically cleared

  - by Telax

  I'm hoping for some advice or suggestions on how best to handle multi threaded access to a value store. My local value storage is designed to hold onto objects which are currently in use. If the object is not in use then it is removed from the store. A value is pumped into my store via thread1, its entry into the store is announced to listeners, and the value is stored. Values coming in on thread1 will either be totally new values or updates for existing values. A timer is used to periodically remove any value from the store which is not currently in use and so all that remains of this value is its ID held locally by an intermediary. Now, an active element on thread2 may wake up and try to access a set of values by passing a set of value IDs which it knows about. Some values will be stored already (great) and some may not (sadface). Those values which are not already stored will be retrieved from an external source. My main issue is that items which have not already been stored and are currently being queried for may arrive in on thread1 before the query is complete. I'd like to try and avoid locking access to the store whilst a query is being made as it may take some time.

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• NHibernate: Using value tables for optimization AND dynamic join

  - by Kostya

  Hi all, My situation is next: there are to entities with many-to-many relation, f.e. Products and Categories. Also, categories has hierachial structure, like a tree. There is need to select all products that depends to some concrete category with all its childs (branch). So, I use following sql statement to do that: SELECT * FROM Products p WHERE p.ID IN ( SELECT DISTINCT pc.ProductID FROM ProductsCategories pc INNER JOIN Categories c ON c.ID = pc.CategoryID WHERE c.TLeft >= 1 AND c.TRight <= 33378 ) But with big set of data this query executes very long and I found some solution to optimize it, look at here: DECLARE @CatProducts TABLE ( ProductID int NOT NULL ) INSERT INTO @CatProducts SELECT DISTINCT pc.ProductID FROM ProductsCategories pc INNER JOIN Categories c ON c.ID = pc.CategoryID WHERE c.TLeft >= 1 AND c.TRight <= 33378 SELECT * FROM Products p INNER JOIN @CatProducts cp ON cp.ProductID = p.ID This query executes very fast but I don't know how to do that with NHIbernate. Note, that I need use only ICriteria because of dynamic filtering\ordering. If some one knows a solution for that, it will be fantastic. But I'll pleasure to any suggestions of course. Thank you ahead, Kostya

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• messed System Files on Mac PPC

  - by glider

  My buddy deleted her System folder from her PPC Mac wanting to get that space for something else. She copied it first in another drive (she had partitioned disk).She haven't emptied the Trash Bin yet. The screen just froze right after she moved the folder to Trash. We tried to use the install disk but even if we try Power-C on booting,it would try to continue,display the apple logo page then quickly follow it with black screen filled with dumps of hex codes and "We are hanging here..." We have a Windows-based PC that we tried to connect using ethernet cable but we can't find her computer from there. What should we do now???

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• Automatically Persisting a Complex Java Object

  - by VeeArr

  For a project I am working on, I need to persist a number of POJOs to a database. The POJOs class definitions are sometimes highly nested, but they should flatten okay, as the nesting is tree-like and contains no cycles (and the base elements are eventually primitives/Strings). It is preferred that the solution used create one table per data type and that the tables will have one field per primitive member in the POJO. Subclassing and similar problems are not issues for this particular project. Does anybody know of any existing solutions that can: Automatically generate a CREATE TABLE definition from the class definition Automatically generate a query to persist an object to the database, given an instance of the object Automatically generate a query to retrieve an object from the database and return it as a POJO, given a key. Solutions that can do this with minimum modifications/annotions to the class files and minimum external configuration are preferred. Example: Java classes //Class to be persisted class TypeA { String guid; long timestamp; TypeB data1; TypeC data2; } class TypeB { int id; int someData; } class TypeC { int id; int otherData; } Could map to CREATE TABLE TypeA ( guid CHAR(255), timestamp BIGINT, data1_id INT, data1_someData INT, data2_id INt, data2_otherData INT ); Or something similar.

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• Why does using 2 memory sticks cause my computer to crash?

  - by hi

  My computer randomly crashes when playing games, but if I remove one memory stick (it does not matter which one I remove), it does not crash anymore. Memory tests do not find errors, I just put in a new power supply (650W), I only have 1 graphics card, so why is this happening? BTW, they are the same memory, same vendor same specs, everything I bought it together (2x2GB) My motherboard is a Asus P5Q Pro, so it supports both dual channel and more than 4gb. Switching slots does nothing, as long as I don't use more than 1 I'm fine.

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• Win32_Product InstallLocation (error)

  - by andrew

  in C#, i'm trying to get some properties from the instances of Win32_Product, but i seem to have an error saying "Object reference not set to an instance of an object." here's the code: class Package { public string productName; public string installDate; public string installLocation; } class InstalledPackages { public static List<Package> get() { List<Package> packages = new List<Package>(); string query = "SELECT * FROM Win32_Product"; ManagementScope oMs = new ManagementScope(); ObjectQuery oQuery = new ObjectQuery(query); ManagementObjectSearcher oSearcher = new ManagementObjectSearcher(oMs, oQuery); ManagementObjectCollection installedPackages = oSearcher.Get(); foreach (ManagementObject package in installedPackages) { Package p = new Package(); p.productName = package["Name"].ToString(); p.installLocation = package["InstallLocation"].ToString(); p.installDate = package["InstallDate"].ToString(); packages.Add(p); } return packages; } } the exception appears when it gets to p.installLocation = package["InstallLocation"].ToString(); also, i get one if i try to do p.installLocation = package["InstallDate2"].ToString(); if i'm asking for InstallDate it works. (i'm using Windows 7 Ultimate x64)

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• Grouping by property value and writing group members

  - by Will S

  I need to group the following list by the department value but am having trouble with the LINQ syntax. Here's my list of objects: var people = new List<Person> { new Person { name = "John", department = new List<fields> {new fields { name = "department", value = "IT"}}}, new Person { name = "Sally", department = new List<fields> {new fields { name = "department", value = "IT"}}}, new Person { name = "Bob", department = new List<fields> {new fields { name = "department", value = "Finance"}}}, new Person { name = "Wanda", department = new List<fields> {new fields { name = "department", value = "Finance"}}}, }; I've toyed around with grouping. This is as far as I've got: var query = from p in people from field in p.department where field.name == "department" group p by field.value into departments select new { Department = departments.Key, Name = departments }; So can iterate over the groups, but not sure how to list the Person names - foreach (var department in query) { Console.WriteLine("Department: {0}", department.Department); foreach (var foo in department.Department) { // ?? } } Any ideas on what to do better or how to list the names of the relevant departments?

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