Search Results

Search found 60932 results on 2438 pages for 'data operations'.

Page 506/2438 | < Previous Page | 502 503 504 505 506 507 508 509 510 511 512 513  | Next Page >

• Error while coping datacolumn with data from one table to another .

  - by Harikrishna

  I have one Datatable like DataTable addressAndPhones; And there are four columns name,address,phoneno,and other details and I only want two columns Name and address from that so I do for that is DataTable addressAndPhones2; addressAndPhones2.Columns.Add(new DataColumn(addressAndPhones.Columns["name"].ColumnName)); addressAndPhones2.Columns.Add(new DataColumn(addressAndPhones.Columns["address"].ColumnName)); But it gives me error so how can I copy fix no of columns data from one table to another table ? ERROR :Object reference not set to an instance of an object.

  Read the article

• What's the best way to share one Entity Framework 4 data model among multiple applications (meant to

  - by Ivan

  A project (a "solution" to say in VS terms) of mine consists of an ASP.Net 4 Dynamic Data Entities web application, some WinForms applications, some WPF applications, some services. All they are intended to work with one SQL Server database, generated from an Entity Framework 4 model as table-per-type, with lots of inheritance and multiple self-referencing relations. Where do I best put my model? In a separate class library, a copy in every project, in one project, etc. What naming should I best use? Is it good idea to name it MySolution.MyClassLibrary.MySolutionEntities, or just MySolutionEntities or just MySolution? Can you share any useful experience on this subject?

  Read the article

• How to access data using VBSCRIPT from a stored procedure which contains values in Temp table ?

  - by Srivigneshwar

  Hi , for testing purpose I wrote a VBscript which will fetch values from Sybase by executing a stored procedure which contains values in temp table. When I run the script I get the following errors , "Either BOF or EOF is True, or the current record has been deleted. Requested operation requires a current record." or "Item cannot be found in the collection corresponding to the requested name or ordinal." Somewhere when I was googling I found that , the above error message will be shown when we use temp table in stored procedure, if that is the reason , then how can I access data via VBscript by executing the stored procedure ??

  Read the article

• Is the time cost constant when bulk inserting data into an indexed table?

  - by SiLent SoNG

  I have created an archive table which will store data for selecting only. Daily there will be a program to transfer a batch of records into the archive table. There are several columns which are indexed; while others are not. I am concerned with time cost per batch insertion: - 1st batch insertion: N1 - 2nd batch insertion: N2 - 3rd batch insertion: N3 The question is: will N1, N2, and N3 roughly be the same, or N3 N2 N1? That is, will the time cost be a constant or incremental, with existence of several indexes? All indexes are non-clustered. The archive table structure is this: create table document ( doc_id int unsigned primary key, owner_id int, -- indexed title smalltext, country char(2), year year(4), time datetime, key ix_owner(owner_id) }

  Read the article

• How do you encrypt data between client and server running in Flash and Java?

  - by ArmlessJohn

  We have a multiclient system where the client is written in Flash and the server is written in Java. Currently, communication is done in Flash by usage of flash.net.Socket and the protocol is written in JSON. The server uses a custom port to receive connections and then proceed to talk with each client. As expected, data is sent and received on both fronts as raw bytes, which are then decoded as needed. We would like to encrypt the communication between clients and server. I have some basic understanding about public/private key encryption, but I do not know what is the best way to exchange keys or what libraries are available (on both languages) to do this. What would be the best strategy to attack this problem and where should I start looking for libraries/methods to implement this encryption?

  Read the article

• What's the fastest way to approximate the period of data using Octave?

  - by John

  I have a set of data that is periodic (but not sinusoidal). I have a set of time values in one vector and a set of amplitudes in a second vector. I'd like to quickly approximate the period of the function. Any suggestions? Specifically, here's my current code. I'd like to approximate the period of the vector x(:,2) against the vector t. Ultimately, I'd like to do this for lots of initial conditions and calculate the period of each and plot the result. function xdot = f (x,t) xdot(1) =x(2); xdot(2) =-sin(x(1)); endfunction x0=[1;1.75]; #eventually, I'd like to try lots of values for x0(2) t = linspace (0, 50, 200); x = lsode ("f", x0, t) plot(x(:,1),x(:,2)); Thank you! John

  Read the article

• Generating dynamic C# based on textual data into the runtime?

  - by WeNeedAnswers

  Is there a quick and easy way to load textual C# into a program. I would like to load the LINQ from the database as an Expression and run it against some data (SQL or Array/List don't mind). I know I can do it using the C# CodeDom/ExpressionTree builder with Assembly Loading and Creating AppDomains, but this seems very long winded. Is there an easier way. I thought with the advent of .net 3.5 that the ExpressionTree would come to my aid, but I now realise that I have to write a parser to use this. Maybe there is a new trick in 4.0? Something along the lines of a dynamic languages Parse would be great. Any suggestions greatly appreciated.

  Read the article

• Java data structure to use with Hibernate to store unknown number of parameters?

  - by Lunikon

  Following problem: I want to render a news stream of short messages based on localized texts. In various places of these messages I have to insert parameters to "customize" them. I guess you know what I mean ;) My question probably falls into the "Which is the best style to do it?" category: How would you store these parameters (they may be Strings and Numbers that need to be formatted according to Locale) in the database? I'm using Hibernate to do the ORM and I can think of the following solutions: build a combined String and save it as such (ugly and hard to maintain I think) do some kind of fancy normalization and and make every parameter a single row on the database (clean I guess, but a performance nightmare) Put the params into an Array, Map or other Java data structure and save it in binary format (probably causes a lot of overhead size-wise) I tend towards option #3 but I'm afraid that it might be to costly in terms of size in the database. What do you think?

  Read the article

• what are the best practices to prevent sql injections

  - by s2xi

  Hi, I have done some research and still confused, This is my outcome of that research. Can someone please comment and advise to how I can make these better or if there is a rock solid implementation already out there I can use? Method 1: array_map('trim', $_GET); array_map('stripslashes', $_GET); array_map('mysql_real_escape_string', $_GET); Method 2: function filter($data) { $data = trim(htmlentities(strip_tags($data))); if (get_magic_quotes_gpc()) $data = stripslashes($data); $data = mysql_real_escape_string($data); return $data; } foreach($_GET as $key => $value) { $data[$key] = filter($value); }

  Read the article

• ASP.NET MVC - How do I implement validation when using Data Repositories? (Visual Basic)

  - by rockinthesixstring

  I've built a UserRepository interface to communicate with my LINQ to SQL Data layer, but I'm trying to figure out how to implement validation. Here is what my AddUser subroutine looks like Public Sub AddUser(ByVal about As String, ByVal birthdate As DateTime, ByVal openid As String, ByVal regionid As Integer, ByVal website As String) Implements IUserRepository.AddUser Dim user = New User user.About = about user.BirthDate = birthdate user.LastSeen = DateTime.Now user.MemberSince = DateTime.Now user.OpenID = openid user.RegionID = regionid user.UserName = String.Empty user.WebSite = website dc.Users.InsertOnSubmit(user) dc.SubmitChanges() End Sub And then my controller will simply call AddUser(...) But I haven't the foggiest idea on how to implement both client side and server side validation on this. (I think I would prefer to use jQuery AJAX and do all of the validation on the server, but I'm totally open to opinions)

  Read the article

• How to encrypt data in php using Public/Private keys?

  - by Xeoncross

  I have a small string of some data (less than 1kb) that I would like to have user agents pass to other sites when they are sent from my site. In order for the other sites to verify that I was the one that created the string I though of two options. The server pings me back to confirm (like paypal, openid, etc..) I use public/private keys to prove I sent the message (like PGP, DKIM, etc..) I don't want to setup HMAC because that would mean I have to use custom keys for each site which would be a pain. Out of those two choices it seems that #2 would save on bandwidth which makes it seem like a better choice. So how can you setup public/private key cryptography using PHP and are there any downsides?

  Read the article

• How to modify posted form data within controller action before sending to view?

  - by Gary

  I want to render the same view after a successful action (rather than use RedirectToAction), but I need to modify the model data that is rendered to that view. The following is a contrived example that demonstrates two methods that that do not work: [AcceptVerbs("POST")] public ActionResult EditProduct(int id, [Bind(Include="UnitPrice, ProductName")]Product product) { NORTHWNDEntities entities = new NORTHWNDEntities(); if (ModelState.IsValid) { var dbProduct = entities.ProductSet.First(p => p.ProductID == id); dbProduct.ProductName = product.ProductName; dbProduct.UnitPrice = product.UnitPrice; entities.SaveChanges(); } /* Neither of these work */ product.ProductName = "This has no effect"; ViewData["ProductName"] = "This has no effect either"; return View(product); } Does anyone know what the correct method is for accomplishing this?

  Read the article

• Stop invalid data in a attribute with foreign key constraint using triggers?

  - by Eternal Learner

  How to specify a trigger which checks if the data inserted into a tables foreign key attribute, actually exists in the references table. If it exist no action should be performed , else the trigger should delete the inserted tuple. Eg: Consider have 2 tables R(A int Primary Key) and S(B int Primary Key , A int Foreign Key References R(A) ) . I have written a trigger like this : Create Trigger DelS BEFORE INSERT ON S FOR EACH ROW BEGIN Delete FROM S where New.A <> ( Select * from R;) ); End; I am sure I am making a mistake while specifying the inner sub query within the Begin and end Blocks of the trigger. My question is how do I make such a trigger ?

  Read the article

• How to do it more efficiently?

  - by David Maricone

  Let's imagine we should get some data... var data = []; //some code omitted that might fill in the data (though might not) Then we need to do something with the data. And my question is how to do it more effectively. Like so?: if (data.length) { for (var i = 0; i < data.length; i++) { //iterate over the data and do something to it } } Or just like so?: for (var i = 0; i < data.length; i++) { //iterate over the data and do something to it } The point is whether to check the length before iterating or not?

  Read the article

• java shift elements in array

  - by Lightk3ira

  Hey I am trying to shift elements forward sending the last element in the array to data[0]. I did the opposite direction but I can't seem to find my mistake in going in this direction. Pos is users inputed shift times amount temp is the temporary holder. data is the array if(pos 0) { do { temp = data[data.length -1]; for(int i =0; i < data.length; i++) { if(i == data.length-1) { data[0] = temp; } else { data[i+1] = data[i]; } } pos--; }while(pos > 0); } Thanks.

  Read the article

• Display data from database using selected value from combo list.. (ASP)

  - by Daisy

  Hi, Does anyone know how to retrieve and display data from database using combo list? What I mean is this..I have a form..in the form there is a combo list and two textfiels..the user need to choose their company using that combo list..once they have chose their company, the address and contact number of the company will be display in the next two textfields called CAddress and CContact..for example, if the user chose company ABC..how can I display the company ABC address and contact number in those textfields? Need help. Thanks.

  Read the article

• How to speed up saving data to database over the internet?

  - by robert_d

  I am using C#, Entity Framework and SQL Server 2008 Express. I am connected to the database over the internet. What is the best method to speed up saving/updating data to database? It takes 87 seconds to save 180 records to the database. It takes only 3.5 seconds to save the same number of records to local (on the same machine) SQL Server. For every record that I save/update I check if record with this primary key exists in the database, if it doesn't exists I simply save it, if it exists I update it using ObjectContext.ApplyCurrentValues(entitySetName, currentEntity) method.

  Read the article

• Which would be better? Storing/access data in a local text file, or in a database?

  - by TerranRich

  Basically, I'm still working on a puzzle-related website (micro-site really), and I'm making a tool that lets you input a word pattern (e.g. "r??n") and get all the matching words (in this case: rain, rein, ruin, etc.). Should I store the words in local text files (such as words5.txt, which would have a return-delimited list of 5-letter words), or in a database (such as the table Words5, which would again store 5-letter words)? I'm looking at the problem in terms of data retrieval speeds and CPU server load. I could definitely try it both ways and record the times taken for several runs with both methods, but I'd rather hear it from people who might have had experience with this. Which method is generally better overall?

  Read the article

• What structure of data use to communicate via tcp/ip in java?

  - by rmaster

  Let's assume I want to send many messages between 2 programs made in java that use TCP sockets. I think the most convienient way is to send objects like: PrintStream ps = new PrintStream(s.getOutputStream()); ObjectOutputStream oos = new ObjectOutputStream(ps); some_kind_of_object_here; oos.writeObject(some_kind_of_object_here); ps.print(oos); I want to send, strings, numbers, HashMaps, boolean values How can I do this using fx 1 object that can store all that properties? I though about ArrayList that is serializable and we can put there everything but is not elegant way. I want to send different types of data because user can choose from a variety of options that server can do for it. Any advices?

  Read the article

• How to achieve "merge" of two data sets with Insert SQL statemen (Oracle DBMS)t?

  - by Roman Kagan

  Hi: What would be the insert SQL statement to merge data from two tables. For example I have events_source_1 table (columns: event_type_id, event_date) and events_source_2 table (same columns) and events_target table (columns: event_type_id, past_event_date nullalbe, future_event_date nullable). Events_source_1 has past events, Events_source_2 has future events and resultant events_target would contain past and future events in the same row for same event_type_id. If there is no past_events but future_events then past_event_date won't be set and only future_event_date will be and the opposite is true too. Thanks a lot in advance for helping me resolving this problem.

  Read the article

• SvcUtil and /dconly generates XSD's for data types NOT marked with the DataContract attribute.

  - by Bellerephon

  Has anyone ever encountered a problem with Svcutil and the /dconly option where it generates metadata for EVERY data type in an Assembly, even if it is NOT marked with with the [DataContract()] attribute? It also appears to be generating metadata for types only referenced in the code, such as XmlDictionaryReaderQuotas even though these are not a part of the physical assembly that I generated metadata on. Some info: Using the .NET 4.0 version of SvcUtil. Does not matter if class is empty or not. No references are specified in the command line for SvcUtil. Command line: "C:\In Progress Work (Prospective)\Prospective Server\Prospective Server\Management\Prospective.Server.Server.NET40.Debug.AnyCPU.dll" /nologo /t:metadata /d:"C:\In Progress Work (Prospective)\Prospective Server\Prospective Server\Management" /dconly

  Read the article

• Not able to get the data from the JSON in OpenSocial App!

  - by Abhishek

  I have follwing JSON: {"mykey":[{name:"Jak",interests:"movies"}]} and following opensocial app code: <script type="text/os-template" require="mykey"> <ul> <li repeat="${mykey}"> <span>Offer id: ${Cur.name}</span> <span>Offer: ${Cur.interests}</span> </li> </ul> </script> but the App is not able to get the data from the JSON? Not able to find out the issue!

  Read the article

• When is porting data from MySQL to CouchDB NOT advisable? Seeking cautionary tales

  - by dan

  I've dabbled in CouchDB and I have pretty good MySQL experience. I've also created one production application that uses both. I like MySQL but I've run into scaling/concurrency issues with MySQL that CouchDB advertises itself as a general solution for. The problem is that I have MySQL based applications that are pretty huge, and I don't really know whether it would be a good idea or not to try to port them over to a CouchDB datastore. I don't want to put in a lot of time and effort only to find out that my application is really not a good fit for CouchDB. Is there any sort of informed consensus on when porting a MySQL based app to CouchDB is NOT advisable? Any cautionary tales? I think CouchDB is really cool and want to use it more. I'd also like to know ahead of time what specific types of data querying scenarios CouchDB is really not good for, or if CouchDB can really replace MySQL for all the applications I create going forward.

  Read the article

• asp.net mvc. Inserting string data from model into javascript. best-practice

  - by Andrew Florko

  Hello everybody, I have to populate javascript code in html layout (hidden fields, method params) with string data from model. Html.Encode is not appropriate for my task because it encodes ' symbol, bypass : (that ruines object attributes declaration) and so on. I wrote static helper class that is used from View like this: alert('<%=ViewHelper.MakeJavaScriptSafe(Model.Message)%>'); I hope there is asp.net in-built function I don't know about for this task. Does it exist really? Thank you in advance.

  Read the article

• How to get dataset to populate data into dbgrid in Delphi 6?

  - by Chris J

  I have created a DBGrid in Delphi 6 and tied it to a DataSource contained in a DataModule. The Dataset for that source in also located in the same module. In the OnShow event for the form, I activate the dataset and set a label equal to the rowcount for the dataset. This shows several hundred rows but nothing shows in the dbgrid. If I activate the dataset in the IDE, the grid populates with the expected data. Does anyone have any idea why this behaviour would change between the IDE and normal runtime? We are also using SDAC connection components. All 3rd party component choices are not mine to change. I can elaborate as necessary for clarification, but I mainly need troubleshooting ideas to start at.

  Read the article

< Previous Page | 502 503 504 505 506 507 508 509 510 511 512 513  | Next Page >