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  • Is there a way to tell if a file is done copying?

    - by Mike Cooper
    The scenario is this: Machine A has files I want to copy to Machine C. Machine A can't access C directly, but can access Machine B that can access Machine C. I am using scp to copy from Machine A to B, and then from B to C. Machine B has limited storage space, so as files come in, I need to copy them to C and delete them from B. The second copy is much faster, so this is no problem with bandwidth. I could do this by hand, but I am lazy. What I would like is to run a script on B or C that will copy each file to C as each one finishes. The scp job is running from A. So what I need is a way to ask (preferably from a bash script) if file X.avi is "done" copying. Each of these files is a different size, and I can't really predict size or time of completion. Edit: by the way, the file transfer times are something about 1 hour from A to B and about 10 minutes from B to C, if time scale matters at all.

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  • Why not install Msvcr71.dll into system32?

    - by hillu
    While looking for an authoritative source for the missing Msvcr71.dll that is needed by a few old applications, I stumbled across the MSDN article Redistribution of the shared C runtime component in Visual C++. The advice given to developers is to drop the DLL into the application's directory instead of system32 since DLLs in this directory are considered before the system paths. What can/will go wrong if I (as an administrator, not a developer) decide to take the lazy path and install Msvcr71.dll (and Msvcp71.dll while I'm at it) into the system32 directory (of 32 bit Windows XP or Windows 7 systems) instead of putting a copy in each application's directory? Is there another good solution to provide the applications with the needed DLLs that doesn't involve copying stuff to the application directories? added after first answers: I understand that incompatible API changes may have been made to the mentioned DLLs, but pretty much every mention of incompatibilities I have found using Google had to do with games or video codecs. Right now, I expect that the risk of breakage is pretty small. Am I missing something?

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  • How can I perform a ping every X minuts and check the response time?

    - by Profete162
    I am currently working in a big company and we have serious latency issues. This is happening in a process control system, and is unacceptable (Open a valve sometimes take 2 minuts before command start) The Network team seems very lazy and I want to check when they say "everything alright on the network". So, I want to create a loop that ping the server and write the result in a text file. I am not a batch expert, but do you think this code is correct to use? @ECHO OFF :LOOPSTART time /T ping xxx.xx.x.x -t >> filename.txt sleep -m 3000 GOTO LOOPSTART

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  • Distributing a Python Software for Linux [closed]

    - by zfranciscus
    Hi, I am writing my first software in Python for Ubuntu (or Debian based Linux). I am looking for a good advise on the best way to distribute my software. The easist alternative that I can think of at the moment is to archive the python code into *.tar.gz, and let user execute the main python script as an executable to run the software. I realize that this may not be the best approach. I looked at the Debian maintainer guide: "http://www.debian.org/doc/maint-guide/ch-dother.en.html", not too sound lazy, but the guide looks very intimidating for a beginner. Are there any other tutorial that show how to create a debian package for a beginner ? If anyone has a suggestion do let me know. Thanks ^_^

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  • Unable to list contents/remove directory (linux ext3)

    - by RedKrieg
    System is CentOS5 x86_64, completely up to date. I've got a folder that can't be listed (ls just hangs, eating memory until it is killed). The directory size is nearly 500k: root@server [/home/user/public_html/domain.com/wp-content/uploads/2010/03]# stat . File: `.' Size: 458752 Blocks: 904 IO Block: 4096 directory Device: 812h/2066d Inode: 44499071 Links: 2 Access: (0755/drwxr-xr-x) Uid: ( 3292/ user) Gid: ( 3287/ user) Access: 2012-06-29 17:31:47.000000000 -0400 Modify: 2012-10-23 14:41:58.000000000 -0400 Change: 2012-10-23 14:41:58.000000000 -0400 I can see the file names if I use ls -1f, but it just repeats the same 48 files ad infinitum, all of which have non-ascii characters somewhere in the file name: La-critic\363-al-servicio-la-privacidad-300x160.jpg When I try to access the files (say to copy them or remove them) I get messages like the following: lstat("/home/user/public_html/domain.com/wp-content/uploads/2010/03/Sebast\355an-Pi\361era-el-balc\363n-150x120.jpg", 0x7fff364c52c0) = -1 ENOENT (No such file or directory) I tried altering the code found on this man page and modified the code to call unlink for each file. I get the same ENOENT error from the unlink call: unlink("/home/user/public_html/domain.com/wp-content/uploads/2010/03/Marca-naci\363n-Madrid-150x120.jpg") = -1 ENOENT (No such file or directory) I also straced a "touch", grabbed the syscalls it makes and replicated them, then tried to unlink the resulting file by name. This works fine, but the folder still contains an entry by the same name after the operation completes and the program runs for an arbitrarily long time (strace output ended up at 20GB after 5 minutes and I stopped the process). I'm stumped on this one, I'd really prefer not to have to take this production machine (hundreds of customers) offline to fsck the filesystem, but I'm leaning toward that being the only option at this point. If anyone's had success using other methods for removing files (by inode number, I can get those with the getdents code) I'd love to hear them. (Yes, I've tried find . -inum <inode> -exec rm -fv {} \; and it still has the problem with unlink returning ENOENT) For those interested, here's the diff between that man page's code and mine. I didn't bother with error checking on mallocs, etc because I'm lazy and this is a one-off: root@server [~]# diff -u listdir-orig.c listdir.c --- listdir-orig.c 2012-10-23 15:10:02.000000000 -0400 +++ listdir.c 2012-10-23 14:59:47.000000000 -0400 @@ -6,6 +6,7 @@ #include <stdlib.h> #include <sys/stat.h> #include <sys/syscall.h> +#include <string.h> #define handle_error(msg) \ do { perror(msg); exit(EXIT_FAILURE); } while (0) @@ -17,7 +18,7 @@ char d_name[]; }; -#define BUF_SIZE 1024 +#define BUF_SIZE 1024*1024*5 int main(int argc, char *argv[]) { @@ -26,11 +27,16 @@ struct linux_dirent *d; int bpos; char d_type; + int deleted; + int file_descriptor; fd = open(argc > 1 ? argv[1] : ".", O_RDONLY | O_DIRECTORY); if (fd == -1) handle_error("open"); + char* full_path; + char* fd_path; + for ( ; ; ) { nread = syscall(SYS_getdents, fd, buf, BUF_SIZE); if (nread == -1) @@ -55,7 +61,24 @@ printf("%4d %10lld %s\n", d->d_reclen, (long long) d->d_off, (char *) d->d_name); bpos += d->d_reclen; + if ( d_type == DT_REG ) + { + full_path = malloc(strlen((char *) d->d_name) + strlen(argv[1]) + 2); //One for the /, one for the \0 + strcpy(full_path, argv[1]); + strcat(full_path, (char *) d->d_name); + + //We're going to try to "touch" the file. + //file_descriptor = open(full_path, O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666); + //fd_path = malloc(32); //Lazy, only really needs 16 + //sprintf(fd_path, "/proc/self/fd/%d", file_descriptor); + //utimes(fd_path, NULL); + //close(file_descriptor); + deleted = unlink(full_path); + if ( deleted == -1 ) printf("Error unlinking file\n"); + break; //Break on first try + } } + break; //Break on first try } exit(EXIT_SUCCESS);

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  • WSUS - Auto-approve only "Needed" updates

    - by Jonathan Rioux
    I'v looked through all the settings in the Automatic Approval menu, but it could not find anything about automatically approve only the needed updates. Because if I check, for instance, to auto-approve only the "Definition updates", it will approve any Definition updates, whether they are needed by my workstations or not. This is because I dont want my WSUS server to download and store updates that are not needed by any of my workstations. Also we are a lazy SMB, and we dont want to waste time to manually approve updates and stuff. Is this even possible ?

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  • Duplicating keepass files instead of creating a new file

    - by BlakBat
    I'm currently using KeePass 2 and syncing them via dropbox. I have a few KeePass files (one for websites, one to store software licenses, etc...) Every time I need a new KeePass file, I just create a copy of the kbdx file, open it, remove all existing entries, change the key transformation rounds to another pseudo-random value. I do not change the master password. I want to know if this was unsafe practice, or was a security risk, compared to just creating a new KeePass file via the "File-New" menu. The reason I don't use the menu: i'm lazy enough to not want to reconfigure "database settings" every time.

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  • Is there any way to automatically prevent running out of memory?

    - by NoahY
    I am often running out of memory on my VPS ubuntu server. I wish there was a way to simply restart apache2 when it starts running out of memory, as that seems to solve the problem. Or am I just too lazy to fix the problem? I do have limited memory on the server... Okay, more information: I'm running apache2 prefork, here are my memory settings (i've been tweaking them...): StartServers 3 MinSpareServers 1 MaxSpareServers 5 MaxClients 150 MaxRequestsPerChild 1000 The VPS has 1 GB of ram, running ubuntu 11.04 32-bit. As for scripts, I have a wordpress network with 5 blogs, an install of AskBot (a python/django stackexchange clone), and an install of MediaWiki that isn't really used. There is also a homebrewed mp3 script that accesses the getid3 library to display information on lists of podcasts, and it seems to be throwing some php errors, not sure if that's the culprit...

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  • Is there a limit on CNAME records for subdomains?

    - by Vilx-
    I've bought a domain, say mydomain.com. I'd like to set up google apps to work with it. As such, I'd like to create subdomains like mail.mydomain.com, docs.mydomain.com, etc. To integrate it with google, I must add to all of them CNAME records to ghs.google.com. However my domain registrar says that they can create only one CNAME in my domain, for which they chose mail.mydomain.com. The rest of them, they say, I must create as A type records. Are they being lazy, or is there some limitation here that I'm not aware of?

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  • Ubuntu reset network configuration

    - by user1103294
    When I boot up my ubuntu server, it cannot connect to my wireless network anymore. It says "waiting for network configuration" for 60 seconds, boots up, but no wireless. I suspect it's because of the following reasons. I used to connect to a wireless connection named 2WIRE555, password: 123abc But then I upgraded my connection and my new wireless connection was named 2WIRE444, password:111111 Being lazy, I simply renamed 2WIRE555 to 2WIRE444 and changed the password accordingly. I was hoping this would work but ever since then my network configurations is messed up. So back to the issue, how do I reset my network configurations for my Ubuntu 11.10 server?

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  • What is the easiest way to copy Chrome's login/passses into KeePass without creating duplicates?

    - by ldigas
    Okey, here's the thing. I have most of my login info in two places; one is in Keepass file and the other is in Chrome. Being a lazy sort of person, and since Chrome/Keepass integration never really started to work the way it should, a couple times a year I use the Nirsoft tool to get the Chrome login/passwords into a textual .csv file and then import it in Keepass. Creating lots of duplicates in the process which I then clean and so on. In the meantime, all the new logins I accumulate just stay in Chrome. As you might notice, this is not really the best way to do it. Is there a faster way to do this; copy logins from Chrome to Keepass without creating duplicates in Keepass, or has anyone perhaps found a way to get Keepass to work with Chrome under Win XP SP3? Keepass 1.0 or 2.0, doesn't make the difference as long as it works.

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  • [SOLVED]Can't enable mysql and mysqli extension in PHP [closed]

    - by Sydcul
    I used to had my website hosted at a hosting company. But i decided to start my own webserver and in order to get phpBB, MediaWiki, etc. working i need PHP and MySQL. So after a bit of screwing around i could get those working but the MySQL and MySQLi extensions do not seem to work. When i use phpMyAdmin, phpBB, whatever it would say it is not installed correctly. I uncommented it in php.ini, i put my PHP folder in path, still not working. Please note i am not a PHP developer at all. Using: Windows Server 2003 Small Buisiness (too lazy to install Linux) Apache2 (not sure what version) PHP 5.2 (threaded, manually installed) MySQL 5.5.28 Thanks in advance, -Sydcul EDIT: Solved. Don't know how, just used the installer and it worked.

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  • Can I change the user that is the default choice in UAC?

    - by Will
    Windows 7 install. I RANU, so I have to hit the UAC every once in awhile. The problem is that it asks me to enter my password to elevate, but I need to enter the domain\username of the box admin (I'm on a domain) and the password. Instead of UAC popping up with my username entered and the caret in the password box, I'd like it to pop up with the domain\username of a different user, specifically the local admin account, entered. This would save me a click and some typing. Sue me, I'm lazy. Is this possible?

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  • What factors should be taken into consideration before buying a computer Moniter (display/screen)?

    - by coding crow
    I work on computer for most of waking day and have been using a 13.3" laptop. I was planning to buy a good monitor/screen/display for sometime now but was lazy. Now I have developed Computer Vision Syndrome and buying a monitor has become immediate priority. I have spend some time on net and trying to understand what should I buy and why? I could only zero down on the size (20") and LED and looking for advice on many other factors like resolution, pixel density, panel technology and so forth. It will be great help if someone experienced can show shed some light on computer monitor best for the programmers spending 8 to 10 hours in front of the screen.

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  • Safe, standard way to load images in ListView on a different thread?

    - by Po
    Before making this question, I have searched and read these ones: http://stackoverflow.com/questions/541966/android-how-do-i-do-a-lazy-load-of-images-in-listview http://stackoverflow.com/questions/1409623/android-issue-with-lazy-loading-images-into-a-listview My problem is I have a ListView, where: Each row contains an ImageView, whose content is to be loaded from the internet Each row's view is recycled as in ApiDemo's List14 What I want ultimately: Load images lazily, only when the user scrolls to them Load images on different thread(s) to maintain responsiveness My current approach: In the adapter's getView() method, apart from setting up other child views, I launch a new thread that loads the Bitmap from the internet. When that loading thread finishes, it returns the Bitmap to be set on the ImageView (I do this using AsyncTask or Handler). Because I recycle ImageViews, it may be the case that I first want to set a view with Bitmap#1, then later want to set it to Bitmap#2 when the user scrolls down. Bitmap#1 may happen to take longer than Bitmap#2 to load, so it may end up overwriting Bitmap#2 on the view. I solve this by maintaining a WeakHashMap that remembers the last Bitmap I want to set for that view. Below is somewhat a pseudocode for my current approach. I've ommitted other details like caching, just to keep the thing clear. public class ImageLoader { // keeps track of the last Bitmap we want to set for this ImageView private static final WeakHashMap<ImageView, AsyncTask> assignments = new WeakHashMap<ImageView, AsyncTask>(); /** Asynchronously sets an ImageView to some Bitmap loaded from the internet */ public static void setImageAsync(final ImageView imageView, final String imageUrl) { // cancel whatever previous task AsyncTask oldTask = assignments.get(imageView); if (oldTask != null) { oldTask.cancel(true); } // prepare to launch a new task to load this new image AsyncTask<String, Integer, Bitmap> newTask = new AsyncTask<String, Integer, Bitmap>() { protected void onPreExecute() { // set ImageView to some "loading..." image } protected Bitmap doInBackground(String... urls) { return loadFromInternet(imageUrl); } protected void onPostExecute(Bitmap bitmap) { // set Bitmap if successfully loaded, or an "error" image if (bitmap != null) { imageView.setImageBitmap(bitmap); } else { imageView.setImageResource(R.drawable.error); } } }; newTask.execute(); // mark this as the latest Bitmap we want to set for this ImageView assignments.put(imageView, newTask); } /** returns (Bitmap on success | null on error) */ private Bitmap loadFromInternet(String imageUrl) {} } Problem I still have: what if the Activity gets destroyed while some images are still loading? Is there any risk when the loading thread calls back to the ImageView later, when the Activity is already destroyed? Moreover, AsyncTask has some global thread-pool underneath, so if lengthy tasks are not canceled when they're not needed anymore, I may end up wasting time loading things users don't see. My current design of keeping this thing globally is too ugly, and may eventually cause some leaks that are beyond my understanding. Instead of making ImageLoader a singleton like this, I'm thinking of actually creating separate ImageLoader objects for different Activities, then when an Activity gets destroyed, all its AsyncTask will be canceled. Is this too awkward? Anyway, I wonder if there is a safe and standard way of doing this in Android. In addition, I don't know iPhone but is there a similar problem there and do they have a standard way to do this kind of task? Many thanks.

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  • Hibernate : Foreign key constraint violation problem

    - by Vinze
    I have a com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException in my code (using Hibernate and Spring) and I can't figure why. My entities are Corpus and Semspace and there's a many-to-one relation from Semspace to Corpus as defined in my hibernate mapping configuration : <class name="xxx.entities.Semspace" table="Semspace" lazy="false" batch-size="30"> <id name="id" column="idSemspace" type="java.lang.Integer" unsaved-value="null"> <generator class="identity"/> </id> <property name="name" column="name" type="java.lang.String" not-null="true" unique="true" /> <many-to-one name="corpus" class="xxx.entities.Corpus" column="idCorpus" insert="false" update="false" /> [...] </class> <class name="xxx.entities.Corpus" table="Corpus" lazy="false" batch-size="30"> <id name="id" column="idCorpus" type="java.lang.Integer" unsaved-value="null"> <generator class="identity"/> </id> <property name="name" column="name" type="java.lang.String" not-null="true" unique="true" /> </class> And the Java code generating the exception is : Corpus corpus = Spring.getCorpusDAO().getCorpusById(corpusId); Semspace semspace = new Semspace(); semspace.setCorpus(corpus); semspace.setName(name); Spring.getSemspaceDAO().save(semspace); I checked and the corpus variable is not null (so it is in database as retrieved with the DAO) The full exception is : com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails (`xxx/Semspace`, CONSTRAINT `FK4D6019AB6556109` FOREIGN KEY (`idCorpus`) REFERENCES `Corpus` (`idCorpus`)) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:931) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2941) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1623) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1715) at com.mysql.jdbc.Connection.execSQL(Connection.java:3249) at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1268) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1541) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1455) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1440) at org.apache.commons.dbcp.DelegatingPreparedStatement.executeUpdate(DelegatingPreparedStatement.java:102) at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:73) at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:33) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2158) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2638) at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:48) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:250) at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:298) at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181) at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:107) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187) at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172) at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27) at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70) at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535) at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523) at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519) at org.springframework.orm.hibernate3.HibernateTemplate$12.doInHibernate(HibernateTemplate.java:642) at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:373) at org.springframework.orm.hibernate3.HibernateTemplate.save(HibernateTemplate.java:639) at xxx.dao.impl.AbstractDAO.save(AbstractDAO.java:26) at org.apache.jsp.functions.semspaceManagement_jsp._jspService(semspaceManagement_jsp.java:218) [...] The foreign key constraint has been created (and added to database) by hibernate and I don't see where the constraint can be violated. The table are innodb and I tried to drop all tables and recreate it the problem remains... EDIT : Well I think I have a start of answer... I change the log level of hibernate to DEBUG and before it crash I have the following log insert into Semspace (name, [...]) values (?, [...]) So it looks like it does not try to insert the idCorpus and as it is not null it uses the default value "0" which does not refers to an existing entry in Corpus table...

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  • Why can't I reference child entities with part of the parent entities composite key

    - by tigermain
    I am trying to reference some child entities with part of the parents composite key not all of it, why cant I? This happens when I use the following mapping instead of that which is commented. I get the following error Foreign key in table VolatileEventContent must have same number of columns as referenced primary key in table LocationSearchView <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="JeanieMaster.Domain.Entities" assembly="JeanieMaster.Domain"> <class name="LocationSearchView" table="LocationSearchView"> <composite-id> <key-property name="LocationId" type="Int32"></key-property> <key-property name="ContentProviderId" type="Int32"></key-property> <key-property name="CategoryId" type="Int32"></key-property> </composite-id> <property name="CompanyName" type="String" not-null="true" update="false" insert="false"/> <property name="Description" type="String" not-null="true" update="false" insert="false"/> <property name="CategoryId" type="Int32" not-null="true" update="false" insert="false"/> <property name="ContentProviderId" type="Int32" not-null="true" update="false" insert="false"/> <property name="LocationId" type="Int32" not-null="true" update="false" insert="false"/> <property name="Latitude" type="Double" update="false" insert="false" /> <property name="Longitude" type="Double" update="false" insert="false" /> <bag name="Events" table="VolatileEventContent" where="DeactivatedOn IS NULL" order-by="StartDate DESC" lazy="false" cascade="none"> <key> <column name="LocationId"></column> <column name="ContentProviderId"></column> <!--<column name="LocationId"></column> <column name="ContentProviderId"></column> <column name="CategoryId"></column>--> </key> <one-to-many class="Event" column="VolatileEventContentId"></one-to-many> </bag> </class> </hibernate-mapping> And VolatileEventContent mapping file <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="JeanieMaster.Domain.Entities" assembly="JeanieMaster.Domain"> <class name="Event" table="VolatileEventContent" select-before-update="false" optimistic-lock="none"> <composite-id> <key-property name="LocationId" type="Int32"></key-property> <key-property name="ContentProviderId" type="Int32"></key-property> </composite-id> <property name="Description" type="String" not-null="true" update="false" insert="false"/> <property name="StartDate" type="DateTime" not-null="true" update="false" insert="false" /> <property name="EndDate" type="DateTime" not-null="true" update="false" insert="false" /> <property name="CreatedOn" type="DateTime" not-null="true" update="false" insert="false" /> <property name="ModifiedOn" type="DateTime" not-null="false" update="false" insert="false" /> <many-to-one name="Location" class="Location" column="LocationId" /> <bag name="Artistes" table="EventArtiste" lazy="false" cascade="none"> <key name="VolatileEventContentId" /> <many-to-many class="Artiste" column="ArtisteId" ></many-to-many> </bag> </class> </hibernate-mapping>

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  • JPA IndirectSet changes not reflected in Spring frontend

    - by Jon
    I'm having an issue with Spring JPA and IndirectSets. I have two entities, Parent and Child, defined below. I have a Spring form in which I'm trying to create a new Child and link it to an existing Parent, then have everything reflected in the database and in the web interface. What's happening is that it gets put into the database, but the UI doesn't seem to agree. The two entities that are linked to each other in a OneToMany relationship like so: @Entity @Table(name = "parent", catalog = "myschema", uniqueConstraints = @UniqueConstraint(columnNames = "ChildLinkID")) public class Parent { private Integer id; private String childLinkID; private Set<Child> children = new HashSet<Child>(0); @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "id", unique = true, nullable = false) public Integer getId() { return this.id; } public void setId(Integer id) { this.id = id; } @Column(name = "ChildLinkID", unique = true, nullable = false, length = 6) public String getChildLinkID() { return this.childLinkID; } public void setChildLinkID(String childLinkID) { this.childLinkID = childLinkID; } @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "parent") public Set<Child> getChildren() { return this.children; } public void setChildren(Set<Child> children) { this.children = children; } } @Entity @Table(name = "child", catalog = "myschema") public class Child extends private Integer id; private Parent parent; @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "id", unique = true, nullable = false) public Integer getId() { return this.id; } public void setId(Integer id) { this.id = id; } @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "ChildLinkID", referencedColumnName = "ChildLinkID", nullable = false) public Parent getParent() { return this.parent; } public void setParent(Parent parent) { this.parent = parent; } } And of course, assorted simple properties on each of them. Now, the problem is that when I edit those simple properties from my Spring interface, everything works beautifully. I can persist new entities of these types and they'll appear when using the JPATemplate to do a find on, say, all Parents (getJpaTemplate().find("select p from Parent p")) or on individual entities by ID or another property. The problem I'm running into is that now, I'm trying to create a new Child linked to an existing Parent through a link from the Parent's page. Here's the important bits of the Controller (note that I've placed the JPA foo in the controller here to make it clearer; the actual JpaDaoSupport is actually in another class, appropriately tiered): protected Object formBackingObject(HttpServletRequest request) throws Exception { String parentArg = request.getParameter("parent"); int parentId = Integer.parseInt(parentArg); Parent parent = getJpaTemplate().find(Parent.class, parentId); Child child = new Child(); child.setParent(parent); NewChildCommand command = new NewChildCommand(); command.setChild(child); return command; } protected ModelAndView onSubmit(Object cmd) throws Exception { NewChildCommand command = (NewChildCommand)cmd; Child child = command.getChild(); child.getParent().getChildren().add(child); getJpaTemplate().merge(child); return new ModelAndView(new RedirectView(getSuccessView())); } Like I said, I can run through the form and fill in the new values for the Child -- the Parent's details aren't even displayed. When it gets back to the controller, it goes through and saves it to the underlying database, but the interface never reflects it. Once I restart the app, it's all there and populated appropriately. What can I do to clear this up? I've tried to call extra merges, tried refreshes (which gave a transaction exception), everything short of just writing my own database access code. I've made sure that every class has an appropriate equals() and hashCode(), have full JPA debugging on to see that it's making appropriate SQL calls (it doesn't seem to make any new calls to the Child table) and stepped through in the debugger (it's all in IndirectSets, as expected, and between saving and displaying the Parent the object takes on a new memory address). What's my next step?

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  • List<T> and IEnumerable difference

    - by Jonas Elfström
    While implementing this generic merge sort, as a kind of Code Kata, I stumbled on a difference between IEnumerable and List that I need help to figure out. Here's the MergeSort public class MergeSort<T> { public IEnumerable<T> Sort(IEnumerable<T> arr) { if (arr.Count() <= 1) return arr; int middle = arr.Count() / 2; var left = arr.Take(middle).ToList(); var right = arr.Skip(middle).ToList(); return Merge(Sort(left), Sort(right)); } private static IEnumerable<T> Merge(IEnumerable<T> left, IEnumerable<T> right) { var arrSorted = new List<T>(); while (left.Count() > 0 && right.Count() > 0) { if (Comparer<T>.Default.Compare(left.First(), right.First()) < 0) { arrSorted.Add(left.First()); left=left.Skip(1); } else { arrSorted.Add(right.First()); right=right.Skip(1); } } return arrSorted.Concat(left).Concat(right); } } If I remove the .ToList() on the left and right variables it fails to sort correctly. Do you see why? Example var ints = new List<int> { 5, 8, 2, 1, 7 }; var mergeSortInt = new MergeSort<int>(); var sortedInts = mergeSortInt.Sort(ints); With .ToList() [0]: 1 [1]: 2 [2]: 5 [3]: 7 [4]: 8 Without .ToList() [0]: 1 [1]: 2 [2]: 5 [3]: 7 [4]: 2 Edit It was my stupid test that got me. I tested it like this: var sortedInts = mergeSortInt.Sort(ints); ints.Sort(); if (Enumerable.SequenceEqual(ints, sortedInts)) Console.WriteLine("ints sorts ok"); just changing the first row to var sortedInts = mergeSortInt.Sort(ints).ToList(); removes the problem (and the lazy evaluation). EDIT 2010-12-29 I thought I would figure out just how the lazy evaluation messes things up here but I just don't get it. Remove the .ToList() in the Sort method above like this var left = arr.Take(middle); var right = arr.Skip(middle); then try this var ints = new List<int> { 5, 8, 2 }; var mergeSortInt = new MergeSort<int>(); var sortedInts = mergeSortInt.Sort(ints); ints.Sort(); if (Enumerable.SequenceEqual(ints, sortedInts)) Console.WriteLine("ints sorts ok"); When debugging You can see that before ints.Sort() a sortedInts.ToList() returns [0]: 2 [1]: 5 [2]: 8 but after ints.Sort() it returns [0]: 2 [1]: 5 [2]: 5 What is really happening here?

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  • Deleting unreferenced child records with nhibernate

    - by Chev
    Hi There I am working on a mvc app using nhibernate as the orm (ncommon framework) I have parent/child entities: Product, Vendor & ProductVendors and a one to many relationship between them with Product having a ProductVendors collection Product.ProductVendors. I currently am retrieving a Product object and eager loading the children and sending these down the wire to my asp.net mvc client. A user will then modify the list of Vendors and post the updated Product back. I am using a custom model binder to generate the modified Product entity. I am able to update the Product fine and insert new ProductVendors. My problem is that dereferenced ProductVendors are not cascade deleted when specifying Product.ProductVendors.Clear() and calling _productRepository.Save(product). The problem seems to be with attaching the detached instance. Here are my mapping files: Product <?xml version="1.0" encoding="utf-8" ?> <id name="Id"> <generator class="guid.comb" /> </id> <version name="LastModified" unsaved-value="0" column="LastModified" /> <property name="Name" type="String" length="250" /> ProductVendors <?xml version="1.0" encoding="utf-8" ?> <id name="Id"> <generator class="guid.comb" /> </id> <version name="LastModified" unsaved-value="0" column="LastModified" /> <property name="Price" /> <many-to-one name="Product" class="Product" column="ProductId" lazy="false" not-null="true" /> <many-to-one name="Vendor" class="Vendor" column="VendorId" lazy="false" not-null="true" /> Custom Model Binder: using System; using Test.Web.Mvc; using Test.Domain; namespace Spoked.MVC { public class ProductUpdateModelBinder : DefaultModelBinder { private readonly ProductSystem ProductSystem; public ProductUpdateModelBinder(ProductSystem productSystem) { ProductSystem = productSystem; } protected override void OnModelUpdated(ControllerContext controllerContext, ModelBindingContext bindingContext) { var product = bindingContext.Model as Product; if (product != null) { product.Category = ProductSystem.GetCategory(new Guid(bindingContext.ValueProvider["Category"].AttemptedValue)); product.Brand = ProductSystem.GetBrand(new Guid(bindingContext.ValueProvider["Brand"].AttemptedValue)); product.ProductVendors.Clear(); if (bindingContext.ValueProvider["ProductVendors"] != null) { string[] productVendorIds = bindingContext.ValueProvider["ProductVendors"].AttemptedValue.Split(','); foreach (string id in productVendorIds) { product.AddProductVendor(ProductSystem.GetVendor(new Guid(id)), 90m); } } } } } } Controller: [AcceptVerbs(HttpVerbs.Post)] public ActionResult Update(Product product) { using (var scope = new UnitOfWorkScope()) { //product.ProductVendors.Clear(); _productRepository.Save(product); scope.Commit(); } using (new UnitOfWorkScope()) { IList<Vendor> availableVendors = _productSystem.GetAvailableVendors(product); productDetailEditViewModel = new ProductDetailEditViewModel(product, _categoryRepository.Select(x => x).ToList(), _brandRepository.Select(x => x).ToList(), availableVendors); } return RedirectToAction("Edit", "Products", new {id = product.Id.ToString()}); } The following test does pass though: [Test] [NUnit.Framework.Category("ProductTests")] public void Can_Delete_Product_Vendors_By_Dereferencing() { Product product; using(UnitOfWorkScope scope = new UnitOfWorkScope()) { Console.Out.WriteLine("Selecting..."); product = _productRepository.First(); Console.Out.WriteLine("Adding Product Vendor..."); product.AddProductVendor(_vendorRepository.First(), 0m); scope.Commit(); } Console.Out.WriteLine("About to delete Product Vendors..."); using (UnitOfWorkScope scope = new UnitOfWorkScope()) { Console.Out.WriteLine("Clearing Product Vendor..."); _productRepository.Save(product); // seems to be needed to attach entity to the persistance manager product.ProductVendors.Clear(); scope.Commit(); } } Going nuts here as I almost have a very nice solution between mvc, custom model binders and nhibernate. Just not seeing my deletes cascaded. Any help greatly appreciated. Chev

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  • nhibernate cascade - problem with detached entities

    - by Chev
    I am going nuts here trying to resolve a cascading update/delete issue :-) I have a Parent Entity with a collection Child Entities. If I modify the list of Child entities in a detached Parent object, adding, deleting etc - I am not seeing the updates cascaded correctly to the Child collection. Mapping Files: <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Domain" namespace="Domain"> <class name="Parent" table="Parent" > <id name="Id"> <generator class="guid.comb" /> </id> <version name="LastModified" unsaved-value="0" column="LastModified" /> <property name="Name" type="String" length="250" /> <bag name="ParentChildren" lazy="false" table="Parent_Children" cascade="all-delete-orphan" inverse="true"> <key column="ParentId" on-delete="cascade" /> <one-to-many class="ParentChildren" /> </bag> </class> <class name="ParentChildren" table="Parent_Children"> <id name="Id"> <generator class="guid.comb" /> </id> <version name="LastModified" unsaved-value="0" column="LastModified" /> <many-to-one name="Parent" class="Parent" column="ParentId" lazy="false" not-null="true" /> </class> </hibernate-mapping> Test [Test] public void Test() { Guid id; int lastModified; // add a child into 1st session then detach using(ISession session = Store.Local.Get<ISessionFactory>("SessionFactory").OpenSession()) { Console.Out.WriteLine("Selecting..."); Parent parent = (Parent) session.Get(typeof (Parent), new Guid("4bef7acb-bdae-4dd0-ba1e-9c7500f29d47")); id = parent.Id; lastModified = parent.LastModified + 1; // ensure the detached version used later is equal to the persisted version Console.Out.WriteLine("Adding Child..."); Child child = (from c in session.Linq<Child>() select c).First(); parent.AddChild(child, 0m); session.Flush(); session.Dispose(); // not needed i know } // attach a parent, then save with no Children using (ISession session = Store.Local.Get<ISessionFactory>("SessionFactory").OpenSession()) { Parent parent = new Parent("Test"); parent.Id = id; parent.LastModified = lastModified; session.Update(parent); session.Flush(); } } I assume that the fact that the product has been updated to have no children in its collection - the children would be deleted in the Parent_Child table. The problems seems to be something to do with attaching the Product to the new session? As the cascade is set to all-delete-orphan I assume that changes to the collection would be propagated to the relevant entities/tables? In this case deletes? What am I missing here? C

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  • [MINI HOW-TO] How To Use Bcc (Blind Carbon Copy) in Outlook 2010

    - by Mysticgeek
    If you want to send an email to a contact or several contacts, you might want to keep some of the recipient email addresses private using the Bcc (Blind Carbon Copy) Field. Here’s how to do it in Outlook 2010. It’s not enabled by default, but adding it as a field for all future emails is a simple process. Launch Outlook and under the Home tab click on the New E-mail button. When the new mail window opens click on the Options tab and in the Show Fields column select Bcc. The Bcc field will appear and you can then put the contacts in there who you want to receive the mail secretly or don’t want to show a certain email address. Now anytime you compose a message, the Bcc field is included. For more on the Bcc field check out the blog post from Mysticgeek – Keep Your Email Contacts Private. Similar Articles Productive Geek Tips How To Switch Back to Outlook 2007 After the 2010 Beta EndsOpen Different Outlook Features in Separate Windows to Improve ProductivityThursday’s Pre-Holiday Lazy Links RoundupCreate an Email Template in Outlook 2003Change Outlook Startup Folder TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon Awe inspiring, inter-galactic theme (Win 7) Case Study – How to Optimize Popular Wordpress Sites

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  • Entity Framework version 1- Brief Synopsis and Tips &ndash; Part 1

    - by Rohit Gupta
    To Do Eager loading use Projections (for e.g. from c in context.Contacts select c, c.Addresses)  or use Include Query Builder Methods (Include(“Addresses”)) If there is multi-level hierarchical Data then to eager load all the relationships use Include Query Builder methods like customers.Include("Order.OrderDetail") to include Order and OrderDetail collections or use customers.Include("Order.OrderDetail.Location") to include all Order, OrderDetail and location collections with a single include statement =========================================================================== If the query uses Joins then Include() Query Builder method will be ignored, use Nested Queries instead If the query does projections then Include() Query Builder method will be ignored Use Address.ContactReference.Load() OR Contact.Addresses.Load() if you need to Deferred Load Specific Entity – This will result in extra round trips to the database ObjectQuery<> cannot return anonymous types... it will return a ObjectQuery<DBDataRecord> Only Include method can be added to Linq Query Methods Any Linq Query method can be added to Query Builder methods. If you need to append a Query Builder Method (other than Include) after a LINQ method  then cast the IQueryable<Contact> to ObjectQuery<Contact> and then append the Query Builder method to it =========================================================================== Query Builder methods are Select, Where, Include Methods which use Entity SQL as parameters e.g. "it.StartDate, it.EndDate" When Query Builder methods do projection then they return ObjectQuery<DBDataRecord>, thus to iterate over this collection use contact.Item[“Name”].ToString() When Linq To Entities methods do projection, they return collection of anonymous types --- thus the collection is strongly typed and supports Intellisense EF Object Context can track changes only on Entities, not on Anonymous types. If you use a Defining Query for a EntitySet then the EntitySet becomes readonly since a Defining Query is the same as a View (which is treated as a ReadOnly by default). However if you want to use this EntitySet for insert/update/deletes then we need to map stored procs (as created in the DB) to the insert/update/delete functions of the Entity in the Designer You can use either Execute method or ToList() method to bind data to datasources/bindingsources If you use the Execute Method then remember that you can traverse through the ObjectResult<> collection (returned by Execute) only ONCE. In WPF use ObservableCollection to bind to data sources , for keeping track of changes and letting EF send updates to the DB automatically. Use Extension Methods to add logic to Entities. For e.g. create extension methods for the EntityObject class. Create a method in ObjectContext Partial class and pass the entity as a parameter, then call this method as desired from within each entity. ================================================================ DefiningQueries and Stored Procedures: For Custom Entities, one can use DefiningQuery or Stored Procedures. Thus the Custom Entity Collection will be populated using the DefiningQuery (of the EntitySet) or the Sproc. If you use Sproc to populate the EntityCollection then the query execution is immediate and this execution happens on the Server side and any filters applied will be applied in the Client App. If we use a DefiningQuery then these queries are composable, meaning the filters (if applied to the entityset) will all be sent together as a single query to the DB, returning only filtered results. If the sproc returns results that cannot be mapped to existing entity, then we first create the Entity/EntitySet in the CSDL using Designer, then create a dummy Entity/EntitySet using XML in the SSDL. When creating a EntitySet in the SSDL for this dummy entity, use a TSQL that does not return any results, but does return the relevant columns e.g. select ContactID, FirstName, LastName from dbo.Contact where 1=2 Also insure that the Entity created in the SSDL uses the SQL DataTypes and not .NET DataTypes. If you are unable to open the EDMX file in the designer then note the Errors ... they will give precise info on what is wrong. The Thrid option is to simply create a Native Query in the SSDL using <Function Name="PaymentsforContact" IsComposable="false">   <CommandText>SELECT ActivityId, Activity AS ActivityName, ImagePath, Category FROM dbo.Activities </CommandText></FuncTion> Then map this Function to a existing Entity. This is a quick way to get a custom Entity which is regular Entity with renamed columns or additional columns (which are computed columns). The disadvantage to using this is that It will return all the rows from the Defining query and any filter (if defined) will be applied only at the Client side (after getting all the rows from DB). If you you DefiningQuery instead then we can use that as a Composable Query. The Fourth option (for mapping a READ stored proc results to a non-existent Entity) is to create a View in the Database which returns all the fields that the sproc also returns, then update the Model so that the model contains this View as a Entity. Then map the Read Sproc to this View Entity. The other option would be to simply create the View and remove the sproc altogether. ================================================================ To Execute a SProc that does not return a entity, use a EntityCommand to execute that proc. You cannot call a sproc FunctionImport that does not return Entities From Code, the only way is to use SSDL function calls using EntityCommand.  This changes with EntityFramework Version 4 where you can return Scalar Types, Complex Types, Entities or NonQuery ================================================================ UDF when created as a Function in SSDL, we need to set the Name & IsComposable properties for the Function element. IsComposable is always false for Sprocs, for UDF's set this to true. You cannot call UDF "Function" from within code since you cannot import a UDF Function into the CSDL Model (with Version 1 of EF). only stored procedures can be imported and then mapped to a entity ================================================================ Entity Framework requires properties that are involved in association mappings to be mapped in all of the function mappings for the entity (Insert, Update and Delete). Because Payment has an association to Reservation... hence we need to pass both the paymentId and reservationId to the Delete sproc even though just the paymentId is the PK on the Payment Table. ================================================================ When mapping insert, update and delete procs to a Entity, insure that all the three or none are mapped. Further if you have a base class and derived class in the CSDL, then you must map (ins, upd, del) sprocs to all parent and child entities in the inheritance relationship. Note that this limitation that base and derived entity methods must all must be mapped does not apply when you are mapping Read Stored Procedures.... ================================================================ You can write stored procedures SQL directly into the SSDL by creating a Function element in the SSDL and then once created, you can map this Function to a CSDL Entity directly in the designer during Function Import ================================================================ You can do Entity Splitting such that One Entity maps to multiple tables in the DB. For e.g. the Customer Entity currently derives from Contact Entity...in addition it also references the ContactPersonalInfo Entity. One can copy all properties from the ContactPersonalInfo Entity into the Customer Entity and then Delete the CustomerPersonalInfo entity, finall one needs to map the copied properties to the ContactPersonalInfo Table in Table Mapping (by adding another table (ContactPersonalInfo) to the Table Mapping... this is called Entity Splitting. Thus now when you insert a Customer record, it will automatically create SQL to insert records into the Contact, Customers and ContactPersonalInfo tables even though you have a Single Entity called Customer in the CSDL =================================================================== There is Table by Type Inheritance where another EDM Entity can derive from another EDM entity and absorb the inherted entities properties, for example in the Break Away Geek Adventures EDM, the Customer entity derives (inherits) from the Contact Entity and absorbs all the properties of Contact entity. Thus when you create a Customer Entity in Code and then call context.SaveChanges the Object Context will first create the TSQL to insert into the Contact Table followed by a TSQL to insert into the Customer table =================================================================== Then there is the Table per Hierarchy Inheritance..... where different types are created based on a condition (similar applying a condition to filter a Entity to contain filtered records)... the diference being that the filter condition populates a new Entity Type (derived from the base Entity). In the BreakAway sample the example is Lodging Entity which is a Abstract Entity and Then Resort and NonResort Entities which derive from Lodging Entity and records are filtered based on the value of the Resort Boolean field =================================================================== Then there is Table per Concrete Type Hierarchy where we create a concrete Entity for each table in the database. In the BreakAway sample there is a entity for the Reservation table and another Entity for the OldReservation table even though both the table contain the same number of fields. The OldReservation Entity can then inherit from the Reservation Entity and configure the OldReservation Entity to remove all Scalar Properties from the Entity (since it inherits the properties from Reservation and filters based on ReservationDate field) =================================================================== Complex Types (Complex Properties) Entities in EF can also contain Complex Properties (in addition to Scalar Properties) and these Complex Properties reference a ComplexType (not a EntityType) DropdownList, ListBox, RadioButtonList, CheckboxList, Bulletedlist are examples of List server controls (not data bound controls) these controls cannot use Complex properties during databinding, they need Scalar Properties. So if a Entity contains Complex properties and you need to bind those to list server controls then use projections to return Scalar properties and bind them to the control (the disadvantage is that projected collections are not tracked by the Object Context and hence cannot persist changes to the projected collections bound to controls) ObjectDataSource and EntityDataSource do account for Complex properties and one can bind entities with Complex Properties to Data Source controls and they will be tracked for changes... with no additional plumbing needed to persist changes to these collections bound to controls So DataBound controls like GridView, FormView need to use EntityDataSource or ObjectDataSource as a datasource for entities that contain Complex properties so that changes to the datasource done using the GridView can be persisted to the DB (enabling the controls for updates)....if you cannot use the EntityDataSource you need to flatten the ComplexType Properties using projections With EF Version 4 ComplexTypes are supported by the Designer and can add/remove/compose Complex Types directly using the Designer =================================================================== Conditional Mapping ... is like Table per Hierarchy Inheritance where Entities inherit from a base class and then used conditions to populate the EntitySet (called conditional Mapping). Conditional Mapping has limitations since you can only use =, is null and IS NOT NULL Conditions to do conditional mapping. If you need more operators for filtering/mapping conditionally then use QueryView(or possibly Defining Query) to create a readonly entity. QueryView are readonly by default... the EntitySet created by the QueryView is enabled for change tracking by the ObjectContext, however the ObjectContext cannot create insert/update/delete TSQL statements for these Entities when SaveChanges is called since it is QueryView. One way to get around this limitation is to map stored procedures for the insert/update/delete operations in the Designer. =================================================================== Difference between QueryView and Defining Query : QueryView is defined in the (MSL) Mapping File/section of the EDM XML, whereas the DefiningQuery is defined in the store schema (SSDL). QueryView is written using Entity SQL and is this database agnostic and can be used against any database/Data Layer. DefiningQuery is written using Database Lanaguage i.e. TSQL or PSQL thus you have more control =================================================================== Performance: Lazy loading is deferred loading done automatically. lazy loading is supported with EF version4 and is on by default. If you need to turn it off then use context.ContextOptions.lazyLoadingEnabled = false To improve Performance consider PreCompiling the ObjectQuery using the CompiledQuery.Compile method

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  • IP address spoofing using Source Routing

    - by iamrohitbanga
    With IP options we can specify the route we want an IP packet to take while connecting to a server. If we know that a particular server provides some extra functionality based on the IP address can we not utilize this by spoofing an IP packet so that the source IP address is the privileged IP address and one of the hosts on the Source Routing is our own. So if the privileged IP address is x1 and server IP address is x2 and my own IP address is x3. I send a packet from x1 to x2 which is supposed to pass through x3. x1 does not actually send the packet. It is just that x2 thinks the packet came from x1 via x3. Now in response if x2 uses the same routing policy (as a matter of courtesy to x1) then all packets would be received by x3. Will the destination typically use the same IP address sequences as specified in the routing header so that packets coming from the server pass through my IP where I can get the required information? Can we not spoof a TCP connection in the above case? Is this attack used in practice?

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  • Merging Waterfall and Agile – Getting the Worst of Both Worlds

    - by Nick Harrison
    Many people have seen and appreciate the elegance and practicality of agile methodologies.   Sadly there is still not widespread adoption.   There is still push back from many directions and from many different sources.   Some people don't understand how it is supposed to work. Some people don't believe that it could possibly work. Some people mistakenly believe that it is just code for a lazy project team trying to wiggle out of structure Some people mistakenly believe that it can work only with a very small highly trained team Some people are afraid of the control that they feel they will be losing. I have seen some people try to merge agile and water fall hoping to achieve the best of both worlds.   Unfortunately, the reality is that you end up with the worst of both worlds.   And they both can get pretty bad. Another Sad Reality Some people in an effort to get buy in for following an Agile Methodology have attempted to merge these two practices.   Sometimes this may stem from trying to assuage individual fears that they are not losing relevance.   Sometimes it may be to meet contractual obligations or to fulfill regulatory requirements.   Sometimes may not know better. These two approaches to software development cannot coexist on the same project. Let's review the main tenants of the Agile Manifesto: Individuals and interactions over processes and tools Working software over comprehensive documentation Customer collaboration over contract negotiation Responding to change over following a plan That is, while there is value in the items on the right, we value the items on the left more. Meanwhile the main tenants of the Waterfall Approach could be summarized as: Processes and procedures over individuals Comprehensive documentation proves that the software works Well defined contracts and negotiations protects the customer relationship If the plan is made right, there should be no change  Merging these two approaches will always end badly.

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