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  • Ada and 'The Book'

    - by Phil Factor
    The long friendship between Charles Babbage and Ada Lovelace created one of the most exciting and mysterious of collaborations ever to have resulted in a technological breakthrough. The fireworks that created by the collision of two prodigious mathematical and creative talents resulted in an invention, the Analytical Engine, which went on to change society fundamentally. However, beyond that, we just don't know what the bulk of their collaborative work was about:;  it was done in strictest secrecy. Even the known outcome of their friendship, the first programmable computer, was shrouded in mystery. At the time, nobody, except close friends and family, had any idea of Ada Byron's contribution to the invention of the ‘Engine’, and how to program it. Her great insight was published in August 1843, under the initials AAL, standing for Ada Augusta Lovelace, her title then being the Countess of Lovelace. It was contained in a lengthy ‘note’ to her translation of a publication that remains the best description of Babbage's amazing Analytical Engine. The secret identity of the person behind those enigmatic initials was finally revealed by Prince de Polignac who, seventy years later, wrote to Ada's daughter to seek confirmation that her mother had, indeed, been the author of the brilliant sentences that described so accurately how Babbage's mechanical computer could be programmed with punch-cards. L.F. Menabrea's paper on the Analytical Engine first appeared in the 'Bibliotheque Universelle de Geneve' in October 1842, and Ada translated it anonymously for Taylor's 'Scientific Memoirs'. Charles Babbage was surprised that she had not written an original paper as she already knew a surprising amount about the way the machine worked. He persuaded her to at least write some explanatory notes. These notes ended up extending to four times the length of the original article and represented the first published account of how a machine could be programmed to perform any calculation. Her example of programming the Bernoulli sequence would have worked on the Analytical engine had the device’s construction been completed, and gave Ada an unassailable claim to have invented the art of programming. What was the reason for Ada's secrecy? She was the only legitimate child of Lord Byron, who was probably the best known celebrity of the age, so she was already famous. She was a senior aristocrat, with titles, a fortune in money and vast estates in the Midlands. She had political influence, and was the cousin of Lord Melbourne, who was the Prime Minister at that time. She was friendly with the young Queen Victoria. Her mathematical activities were a pastime, and not one that would be considered by others to be in keeping with her roles and responsibilities. You wouldn't dare to dream up a fictional heroine like Ada. She was dazzlingly beautiful and talented. She could speak several languages fluently, and play some musical instruments with professional skill. Contemporary accounts refer to her being 'accomplished in science, art and literature'. On top of that, she was a brilliant mathematician, a talent inherited from her mother, Annabella Milbanke. In her mother's circle of literary and scientific friends was Charles Babbage, and Ada's friendship with him dates from her teenage zest for Mathematics. She was one of the first people he'd ever met who understood what he had attempted to achieve with the 'Difference Engine', and with whom he could converse as intellectual equals. He arranged for her to have an education from the most talented academics in the country. Ada melted the heart of the cantankerous genius to the point that he became a faithful and loyal father-figure to her. She was one of the very few who could grasp the principles of the later, and very different, ‘Analytical Engine’ which was designed from the start to tackle a variety of tasks. Sadly, Ada Byron's life ended less than a decade after completing the work that assured her long-term fame, in November 1852. She was dying of cancer, her gambling habits had caused her to run up huge debts, she'd had more than one affairs, and she was being blackmailed. Her brilliant but unempathic mother was nursing her in her final illness, destroying her personal letters and records, and repaying her debts. Her husband was distraught but helpless. Charles Babbage, however, maintained his steadfast paternalistic friendship to the end. She appointed her loyal friend to be her executor. For years, she and Babbage had been working together on a secret project, known only as 'The Book'. We have a clue to what it was in a letter written by her nine years earlier, on 11th August 1843. It was a joint project by herself and Lord Lovelace, her husband, and was intended to involve Babbage's 'undivided energies'. It involved 'consulting your Engine' (it required Babbage’s computer). The letter gives no hint about the project except for the high-minded nature of its purpose, and its highly mathematical nature.  From then on, the surviving correspondence between the two gives only veiled references to 'The Book'. There isn't much, since Babbage later destroyed any letters that could have damaged her reputation within the Establishment. 'I cannot spare the book today, which I am very sorry for. At the moment I want it for constant reference, but I think you can have it tomorrow' (Oct 1844)  And 'I will send you the book directly, and you can say, when you receive it, how long you will want to keep it'. (Nov 1844)  The two of them were obviously intent on the work: She writes, four years later, 'I have an engagement for Wednesday which will prevent me from attending to your wishes about the book' (Dec 1848). This was something that they both needed to work on, but could not do in parallel: 'I will send the book on Tuesday, and it can be left with you till Friday' (11 Feb 1849). After six years work, it had been so well-handled that it was beginning to fall apart: 'Don't forget the new cover you promised for the book. The poor book is very shabby and wants one' (20 Sept 1849). So what was going on? The word 'book' was not a code-word: it was a real book, probably a 'printer's blank', plain paper, but properly bound so printers and publishers could show off how the published work might look. The hints from the correspondence are of advanced mathematics. It is obvious that the book was travelling between them, back and forth, each one working on it for less than a week before passing it back. Ada and her husband were certainly involved in gambling large sums of money on the horses, and so most biographers have concluded that the three of them were trying to calculate the mathematical odds on the horses. This theory has three large problems. Firstly, Ada's original letter proposing the project refers to its high-minded nature. Babbage was temperamentally opposed to gambling and would scarcely have given so much time to the project, even though he was devoted to Ada. Secondly, Babbage would have very soon have realized the hopelessness of trying to beat the bookies. This sort of betting never attracts his type of intellectual background. The third problem is that any work on calculating the odds on horses would not need a well-thumbed book to pass back and forth between them; they would have not had to work in series. The original project was instigated by Ada, along with her husband, William King-Noel, 1st Earl of Lovelace. Charles Babbage was invited to join the project after the couple had come up with the idea. What could William have contributed? One might assume that William was a Bertie Wooster character, addicted only to the joys of the turf, but this was far from the truth. He was a scientist, a Cambridge graduate who was later elected to be a Fellow of the Royal Society. After Eton, he went to Trinity College, Cambridge. On graduation, he entered the diplomatic service and acted as secretary under Lord Nugent, who was Lord Commissioner of the Ionian Islands. William was very friendly with Babbage too, able to discuss scientific matters on equal terms. He was a capable engineer who invented a process for bending large timbers by the application of steam heat. He delivered a paper to the Institution of Civil Engineers in 1849, and received praise from the great engineer, Isambard Kingdom Brunel. As well as being Lord Lieutenant of the County of Surrey for most of Victoria's reign, he had time for a string of scientific and engineering achievements. Whatever the project was, it is unlikely that William was a junior partner. After Ada's death, the project disappeared. Then, two years later, Babbage, through one of his occasional outbursts of temper, demonstrated that he was able to decrypt one of the most powerful of secret codes, Vigenère's autokey cipher.  All contemporary diplomatic and military messages used a variant of this cipher. Babbage had made three important discoveries, namely, the mathematical law of this cipher, the principle of the key periodicity, and the technique of the symmetry of position. The technique is now known as the Kasiski examination, also called the Kasiski test, but Babbage got there first. At one time, he listed amongst his future projects, the writing of a book 'The Philosophy of Decyphering', but it never came to anything. This discovery was going to change the course of history, since it was used to decipher the Russians’ military dispatches in the Crimean war. Babbage himself played a role during the Crimean War as a cryptographical adviser to his friend, Rear-Admiral Sir Francis Beaufort of the Admiralty. This is as much as we can be certain about in trying to make sense of the bulk of the time that Charles Babbage and Ada Lovelace worked together. Nine years of intensive work, involving the 'Engine' and a great deal of mathematics and research seems to have been lost: or has it? I've argued in the past http://www.simple-talk.com/community/blogs/philfactor/archive/2008/06/13/59614.aspx that the cracking of the Vigenère autokey cipher, was a fundamental motive behind the British Government's support and funding of the 'Difference Engine'. The Duke of Wellington, whose understanding of the military significance of being able to read enemy dispatches, was the most steadfast advocate of the project. If the three friends were actually doing the work of cracking codes by mathematical techniques that used the techniques of key periodicity, and symmetry of position (the use of a book being passed quickly to and fro is very suggestive), intending to then use the 'Engine' to do the routine cracking of each dispatch, then this is a rather different story. The project was Ada and William's idea. (William had served in the diplomatic service and would be familiar with the use of codes). This makes Ada Lovelace the initiator of a project which, by giving both Britain, and probably the USA, a diplomatic and military advantage in the second part of the Nineteenth century, changed world history. Ada would never have wanted any credit for cracking the cipher, and developing the method that rendered all contemporary military and diplomatic ciphering techniques nugatory; quite the reverse. And it is clear from the gaps in the record of the letters between the collaborators that the evidence was destroyed, probably on her request by her irascible but intensely honorable executor, Charles Babbage. Charles Babbage toyed with the idea of going public, but the Crimean war put an end to that. The British Government had a valuable secret, and intended to keep it that way. Ada and Charles had quite often discussed possible moneymaking projects that would fund the development of the Analytic Engine, the first programmable computer, but their secret work was never in the running as a potential cash cow. I suspect that the British Government was, even then, working on the concealment of a discovery whose value to the nation depended on it remaining so. The success of code-breaking in the Crimean war, and the American Civil war, led to the British and Americans  subsequently giving much more weight and funding to the science of decryption. Paradoxically, this makes Ada's contribution even closer to the creation of Colossus, the first digital computer, at Bletchley Park, specifically to crack the Nazi’s secret codes.

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  • Entity framework createquery question.

    - by Tony Heflin
    I am trying to create a generic search form to use in an EF app. I want to be ably to specify the entity to query at runtime below is a simplified version of the code. cx is the contect object, valuelists is the entity in question. 1: Dim q As String = "select c from intactentities.valuelists as c" 2: Dim x = cx.CreateQuery(Of ValueLists)(q) 3: TextBox1.Text = x.Count This works but I need to remove the hardcoded reference to valuelists in line 3. I expect I am overlooking something simple can anyone suggest a simple solution? Thanks Tony

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  • How to set post parameters in WebClient class in a Silverlight app.

    - by cmaduro
    First of all, I wrote a simple php page, that picks up some variables from the POST parameters such as a query and a authentication string, and returns the result as xml. I intend to call this page with the WebClient class from a Silverlight application. I'm using POST because we are querying the database with any valid sql statement, not only select statements. The WebClient class uses the UploadDataAsync method to post to a http server, however it requires the post parameters be passed as a NameValueCollection. This class is missing in the Silverlight runtime. How do I proceed???

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  • C# LINQ Oracle date Functions

    - by user1079925
    I am trying to generate a sql statement to be used in Oracle11g, using linq. The problem arises when using dates: The SQL generated by linq gives SELECT * FROM <table> WHERE start_date > '24/11/2012 00:00:00' and end_date < '28/11/2012 00:00:00' This causes an oracle error: ORA-01830 - date format picture ends before converting entire input string Adding TO_DATE to the query fixes the ORA-01830, as it is converting the string to a oracle date whilst now knowing the date format. SELECT * FROM <table> WHERE start_date > TO_DATE('24/11/2012 00:00:00','DD/MM/YYYY HH24:MI:SS') and end_date < TO_DATE('28/11/2012 00:00:00','DD/MM/YYYY HH24:MI:SS') So, is there a way to add TO_DATE to LINQ (for oracle)? If not, please tell me how to work around this issue. Thanks

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  • mySQL auto increment problem: Duplicate entry '4294967295' for key 1

    - by Josh
    I have a table of emails. The last record in there for an auto increment id is 3780, which is a legit record. Any new record I now insert is being inserted right there. However, in my logs I have the occasional: Query FAIL: INSERT INTO mail.messages (timestamp_queue) VALUES (:time); Array ( [0] => 23000 [1] => 1062 [2] => Duplicate entry '4294967295' for key 1 ) Somehow, the autoincrement jumped up to the INT max of 4294967295 Why on god's green earth would this get jumped up so high? I have no inserts with an id field. The show status for that table, Auto_increment table now reads: 4294967296 How could something like this occur? I realize the id field should perhaps be a big int, but the worry I have is that somehow this thing jumps back up. Josh

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  • How to group data in PHP inside the while loop

    - by christian
    I query in a database and loop the result using while and heres the sample data retrieve: echo $db->f("FirstName")."===".$db->f("Question")."=".$db->f("Answer")."<br>"; Michael===Q2=allergy Michael===Q2=Hives Michael===Q6=A lot Michael===Q8_A=Daktacort Michael===Q1=Itch Michael===Q5=Smoke Michael===Q8_A=Diprogenta Christian===Q1=Stuffy Christian===Q6=A lot Christian===Q1=Clear Christian===Q5=Pollen How can I group them according to name and to their Q value? I want something like this result: Name Q1 Q2 ..... so on and so fort. Michael Itch Hives, Allergy Christian Stuffy

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  • jQuery in sharepoint retruning Object Expected

    - by Simon Thompson
    When I add jquery to sharepoint 2007 (MOSS) and try and use it on a page no matter what I write on the client i get an "object expected" at the line/column where the "$" appears. I have used fiddler to check that the client is downloading the query JS (which it is) But its like its being ignore and therefor eth "$" is not understood. Searching google everybody is saying its the selector not finding the elements but see code below I do not see how it can not find my very simple example. In master page in header <script type="text/javascript" src="jquery.min.js"></script> version 1.4.2 On a page <a href="javascript:abc();">Testing</a> <script> function abc(){ $("#simon").css("border","3px solid red"); } </script> <div id="simon">

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  • SQLPlus - spooling to multiple files from PL/SQL blocks

    - by FrustratedWithFormsDesigner
    I have a query that returns a lot of data into a CSV file. So much, in fact, that Excel can't open it - there are too many rows. Is there a way to control spool to spool to a new file everytime 65000 rows have been processed? Ideally, I'd like to have my output in files named in sequence, such as large_data_1.csv, large_data_2.csv, large_data_3.csv, etc... I could use dbms_output in a PL/SQL block to control how many rows are output, but then how would I switch files, as spool does not seem to be accessible from PL/SQL blocks? (Oracle 10g)

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  • Best Practices for persisting iPod Playlist (MPMediaItemCollection) across sessions

    - by coneybeare
    When using in-app audio in the iPhone SDK, it is possible to allow users to select a list from their ipod library and create an in-app local playlist. If I want to persist this choice, it is easy to serialize the data and write to file, then recover. Just vanilla like this, however, leads me to think there is going to be something wrong. For example, what if the user syncs and removes sounds? I can loop across them all and query the iPod DB at setup time, but with lists that could be 50,000 long, this could take some time. How are other people doing this and what are some gotchas that I haven't though about?

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  • Can PetaPoco populate an object using a stored procedure with a join clause?

    - by Mark Kadlec
    I have a stored procedure that does something similar to: SELECT a.TaskId, b.CompanyCode FROM task a JOIN company b ON b.CompanyId = a.CompanyId; I have an object called TaskItem that has the TaskId and CompanyCode properties, but when I execute the following (which I would have assumed worked): var masterDatabase = new Database("MasterConnectionString"); var s = PetaPoco.Sql.Builder.Append("EXEC spGetTasks @@numberOfTasks = @0", numberOfTasks); var tasks = masterDatabase.Query<Task>(s); The problem is that the CompanyCode column does not exist in the task table, I did a trace and it seems that PetaPoco is trying to select all the properties from the task table and populating using the stored procedure. How can I use PetaPoco to simply populate the list of task objects with the results of the stored procedure?

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  • Is this so bad when using MySQL queries in PHP?

    - by alex
    I need to update a lot of rows, per a user request. It is a site with products. I could... Delete all old rows for that product, then loop through string building a new INSERT query. This however will lose all data if the INSERT fails. Perform an UPDATE through each loop. This loop currently iterates over 8 items, but in the future it may get up to 15. This many UPDATEs doesn't sound like too good an idea. Change DB Schema, and add an auto_increment Id to the rows. Then first do a SELECT, get all old rows ids in a variable, perform one INSERT, and then a DELETE WHERE IN SET. What is the usual practice here? Thanks

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  • Using Repository and Unit of Work patterns with Entity Framework 4.0 and MVC 2

    - by Mr. D
    Hi, I'm following this article Using Repository and Unit of Work patterns with Entity Framework 4.0. I'm tying to implement the Repository and Unit of work pattern, using Asp.Net MVC 2 and Entity Framework 4. Please let me know if I'm doing it right... In the Models folder: Northwind.edmx Products.cs (POCO class) ProductRepository.cs (Did my product query) IProductRepository.cs NorthwindContext.cs IUnitOfWork.cs In the Controller folder: ProductController.cs (Retrieve from ProductRepository.cs and Pass it to the view) When I run the application, I'm getting error message: Mapping and metadata information could not be found for EntityType 'NorthwindMvcPoco.Models.Category'. I don't know what I'm doing wrong. I search through whole web and I couldn't resolve this issue. Please help me.

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  • Entity Framework - SaveChanges with GUID as EntityKey

    - by MissingLinq
    I have a SQL Server 2008 database table that uses uniqueidentifier as a primary key. On inserts, the key is generated on the database side using the newid() function. This works fine with ADO.NET. But when I set up this table as an entity in an Entity Framework 4 model, there's a problem. I am able to query the entity just fine, but when creating a new entity and invoking SaveChanges() on the context, the generated uniqueidentifier on the database is all zeros. I understand there was an issue with EF v1 where this scenario did not work, requiring creating the GUID on the client prior to calling SaveChanges. However, I had read in many places that they were planning to fix this in EF 4. My question -- is this scenario (DB-side generation of uniqueidentifier) still not supported in EF4? Are we still stuck with generating the GUID on the client?

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  • DB structure for Twitter home/Facebook wall?

    - by mathon12
    Basically a live feed of all your friends' recent posts. In a stupid sort of approach I think I'd start by building a query like: SELECT * FROM tblposts WHERE userid=friend_id_1OR userid=friend_id_2...... and so on Where friend_id_% is the userid of a friend from your friends list. But this must be a very inefficient way of doing it, right? Is there any faster way of doing this in MySQL? Maybe some clever DB schema? (I know FB uses Hadoob but I'm not experienced enough to go that far :( )

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  • MS Access 2003 - ordering the string values for a chart not alphabetical

    - by Justin
    Here is a silly question. Lets say I have a query that produces for a list box, and it produces values for three stores Store A 18 Store B 32 Store C 54 Now if I ORDER BY in the sql statement the only thing it will do is descending or ascending alphabetically but I want a certain order (only because THEY WANT A CERTAIN ORDER) .....so is there a way for me to add something to the SQL to get Store B Store C Store A i.e. basically row by row what i want. thanks!

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  • Using constructor to load data in subsonic3?

    - by Dennis
    I'm getting an error while trying to load an record through the constructor. The constructor is: public Document(Expression<Func<Document,bool>> expression); and i try to load a single item in like this var x = new Document(f=>f.publicationnumber=="xxx"); publicationnumber isn't a key but tried making an it an unique key and still no go.. Am i totally wrong regarding the use of the constructor? and can someone please tell me how to use that constructor? The error i'm getting is: Test method TestProject1.UnitTest1.ParseFileNameTwoProductSingleLanguage threw exception: System.NullReferenceException: with the following stacktrace: SubSonic.Query.SqlQuery.Where[T](Expression1` expression) Load`[T]`(T item, Expression1expression) db.Document..ctor(Expression``1 expression) in C:\@Projects\DocumentsSearchAndAdmin\DocumentsSearchAndAdmin\Generated\ActiveRecord.cs: line 5613 rest removed for simplicity Regards Dennis

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  • GAE/Django Templates (0.96) filters to get LENGTH of GqlQuery and filter it

    - by Halst
    I pass the query with comments to my template: COMM = CommentModel.gql("ORDER BY created") doRender(self,CP.template,{'CP':CP,'COMM':COMM, 'authorize':authorize()}) And I want to output the number of comments as a result, and I try to do things like that: <a href="...">{{ COMM|length }} comments</a> Thats does not work (yeah, since COMM is GqlQuery, not a list). What can I do with that? Is there a way to convert GqlQuery to list or is there another solution? (first question) Second question is, how to filter this list in template? Is there a construct like this: <a href="...">{{ COMM|where(reference=smth)|length }} comments</a> so that I can get not only the number of all comments, but only comments with certain db.ReferenceProperty() property, for example. Last question: is it weird to do such things using templates?

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  • Sharepoint - connectable receiving, XSLT editable web part?

    - by Corey O.
    You can use the "Data View" webpart to take data from a database call, then you can edit the XSLT manually to make it look and do whatever you want, within the scope of that data and XSLT capabilities. Is there a web part that allows me to do the same thing, but with data that is received by a connected webpart source rather than a database set? For example: I'd like to be able to pull in a Data View webpart that queries a bunch of data and makes it available all over the page. Then, I would like to hide that Data View. Once it is hidden, I'd like to be able to take another customizable webpart and pull a field (or multiple fields if possible) from the Data View webpart via a webpart connection. This would allow me to display various fields in creative formats without having to call the same query multiple times on the same page by different webparts. Is there an in house webpart that will allow me to do this?

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  • Eager-loading association count with Arel (Rails 3)

    - by Matchu
    Simple task: given that an article has many comments, be able to display in a long list of articles how many comments each article has. I'm trying to work out how to preload this data with Arel. The "Complex Aggregations" section of the README file seems to discuss that type of situation, but it doesn't exactly offer sample code, nor does it offer a way to do it in two queries instead of one joined query, which is worse for performance. Given the following: class Article has_many :comments end class Comment belongs_to :article end How can I preload for an article set how many comments each has?

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  • how do I access XHR responseBody from Javascript?

    - by Cheeso
    I've got a web page that uses XMLHttpRequest to download a binary resource. Because it's binary I'm trying to use xhr.responseBody to access the bytes. I've seen a few posts suggesting that it's impossible to access the bytes directly from Javascript. This sounds crazy to me. Weirdly, xhr.responseBody is accessible from VBScript, so the suggestion is that I must define a method in VBScript in the webpage, and then call that method from Javascript. See jsdap for one example. var IE_HACK = (/msie/i.test(navigator.userAgent) && !/opera/i.test(navigator.userAgent)); if (IE_HACK) document.write('<script type="text/vbscript">\n\ Function BinaryToArray(Binary)\n\ Dim i\n\ ReDim byteArray(LenB(Binary))\n\ For i = 1 To LenB(Binary)\n\ byteArray(i-1) = AscB(MidB(Binary, i, 1))\n\ Next\n\ BinaryToArray = byteArray\n\ End Function\n\ </script>'); var xml = (window.XMLHttpRequest) ? new XMLHttpRequest() // Mozilla/Safari/IE7+ : (window.ActiveXObject) ? new ActiveXObject("MSXML2.XMLHTTP") // IE6 : null; // Commodore 64? xml.open("GET", url, true); if (xml.overrideMimeType) { xml.overrideMimeType('text/plain; charset=x-user-defined'); } else { xml.setRequestHeader('Accept-Charset', 'x-user-defined'); } xml.onreadystatechange = function() { if (xml.readyState == 4) { if (!binary) { callback(xml.responseText); } else if (IE_HACK) { // call a VBScript method to copy every single byte callback(BinaryToArray(xml.responseBody).toArray()); } else { callback(getBuffer(xml.responseText)); } } }; xml.send(''); Is this really true? The best way? copying every byte? For a large binary stream that's not gonna be very efficient. There is also a possible technique using ADODB.Stream, which is a COM equivalent of a MemoryStream. See here for an example. It does not require VBScript but does require a separate COM object. if (typeof (ActiveXObject) != "undefined" && typeof (httpRequest.responseBody) != "undefined") { // Convert httpRequest.responseBody byte stream to shift_jis encoded string var stream = new ActiveXObject("ADODB.Stream"); stream.Type = 1; // adTypeBinary stream.Open (); stream.Write (httpRequest.responseBody); stream.Position = 0; stream.Type = 1; // adTypeBinary; stream.Read.... /// ???? what here } I don't think that's gonna work - ADODB.Stream is disabled on most machines these days. In The IE8 developer tools - the IE equivalent of Firebug - I can see the responseBody is an array of bytes and I can even see the bytes themselves. The data is right there. I don't understand why I can't get to it. Is it possible for me to read it with responseText? hints? (other than defining a VBScript method)

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  • Dynamic Data Associate Related Table Value?

    - by davemackey
    I have create a LINQ-to-SQL project in Visual Studio 2010 using Dynamic Data. In this project I have two tables. One is called phones_extension and the other phones_ten. The list of columns in phones_extension looks like this: id, extension, prefix, did_flag, len, ten_id, restriction_class_id, sfc_id, name_display, building_id, floor, room, phone_id, department_id In phones_ten it looks like this: id, name, pbxid Now, I'd like to be able to somehow make it so that there is an association (or inheritance?) that essentially results in me being able to make a query like phones_extension.ten and it gives me the result of phones_ten.name. Right now I have to get phones_extension.ten_id and then match that against phones_ten.id - I'm trying to get the DBML to handle this translation automatically. Is this possible?

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  • Indexing vs. no indexing when inserting records

    - by jbu
    I have a few questions about whether or not it would be best to not use indexing. BACKGROUND: My records have a timestamp attribute, and the records will be inserted in order of their timestamps (i.e., inserted chronologically). QUESTIONS: If I DON'T use indexing is it typical for the database to insert the records in the order that they were inserted? If answer to #1 is yes, when I do a "SELECT .. WHERE timestamp X" type query will the database be efficient at it, or will it have to go through every single record since it isn't indexed? I would assume if there were no index, the database would not "know" that the records were inserted in sorted order and could not, therefore, make use of sorted property of the database. I assume a clustered index would be best for these types of records & their inserts. Please let me know what you guys think. Thanks, jbu

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  • Counting and joining two tables

    - by Eikern
    Eventhosts – containing the three regular hosts and an "other" field (if someone is replacing them) eventid | host (SET[Steve,Tim,Brian,other]) ------------------------------------------- 1 | Steve 2 | Tim 3 | Brian 4 | other 5 | other Event id | other | name etc. ---------------------- 1 | | … 2 | | … 3 | | … 4 | Billy | … 5 | Irwin | … This query: SELECT h.host, COUNT(*) AS hostcount FROM host AS h LEFT OUTER JOIN event AS e ON h.eventid = e.id GROUP BY h.host Returns Steve | 1 Tim | 1 Brian | 1 other | 2 I want it to return Steve | 1 Tim | 1 Brian | 1 Billy | 1 Irwin | 1 OR Steve | | 1 Tim | | 1 Brian | | 1 other | Billy | 1 other | Irwin | 1 Can someone tell me how I can achieve this or point me in a direction?

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  • How to configure a WCF service to only accept a single client identified by a x509 certificate

    - by Johan Levin
    I have a WCF client/service app that relies on secure communication between two machines and I want to use use x509 certificates installed in the certificate store to identify the server and client to each other. I do this by configuring the binding as <security authenticationMode="MutualCertificate"/>. There is only client machine. The server has a certificate issued to server.mydomain.com installed in the Local Computer/Personal store and the client has a certificate issued to client.mydomain.com installed in the same place. In addition to this the server has the client's public certificate in Local Computer/Trusted People and the client has the server's public certificate in Local Computer/Trusted People. Finally the client has been configured to check the server's certificate. I did this using the system.servicemodel/behaviors/endpointBehaviors/clientCredentials/serviceCertificate/defaultCertificate element in the config file. So far so good, this all works. My problem is that I want to specify in the server's config file that only clients that identify themselves with the client.mydomain.com certificate from the Trusted People certificate store are allowed to connect. The correct information is available on the server using the ServiceSecurityContext, but I am looking for a way to specify in app.config that WCF should do this check instead of my having to check the security context from code. Is that possible? Any hints would be appreciated. By the way, my server's config file looks like this so far: <?xml version="1.0" encoding="utf-8" ?> <configuration> <system.serviceModel> <services> <service name="MyServer.Server" behaviorConfiguration="CertificateBehavior"> <endpoint contract="Contracts.IMyService" binding="customBinding" bindingConfiguration="SecureConfig"> </endpoint> <host> <baseAddresses> <add baseAddress="http://localhost/SecureWcf"/> </baseAddresses> </host> </service> </services> <behaviors> <serviceBehaviors> <behavior name="CertificateBehavior"> <serviceCredentials> <serviceCertificate storeLocation="LocalMachine" x509FindType="FindBySubjectName" findValue="server.mydomain.com"/> </serviceCredentials> </behavior> </serviceBehaviors> </behaviors> <bindings> <customBinding> <binding name="SecureConfig"> <security authenticationMode="MutualCertificate"/> <httpTransport/> </binding> </customBinding> </bindings> </system.serviceModel> </configuration>

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  • POCO Best Practice

    - by Paul Johnson
    All, I have a series of domain objects (project is NHibernate based). Currently as per 'good practice' they define only the business objects, comprising properties and methods specific to each objects function within the domain. However one of the objects has a requirement to send an SMTP message. I have a simple SMTP client class defined in a separate 'Utilities' assembly. In order to use this mail client from within the POCO, I would need to hold a reference to the utilities assembly in the domain. My query is this... Is it a departure from best practice to hold such a reference in a POCO, for the purpose of gaining necessary business functionality. Kind Regards Paul J.

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