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  • Saving and retrieving image in SQL database from C# problem

    - by Mobin
    I used this code for inserting records in a person table in my DB System.IO.MemoryStream ms = new System.IO.MemoryStream(); Image img = Image_Box.Image; img.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp); this.personTableAdapter1.Insert(NIC_Box.Text.Trim(), Application_Box.Text.Trim(), Name_Box.Text.Trim(), Father_Name_Box.Text.Trim(), DOB_TimePicker.Value.Date, Address_Box.Text.Trim(), City_Box.Text.Trim(), Country_Box.Text.Trim(), ms.GetBuffer()); but when i retrieve this with this code byte[] image = (byte[])Person_On_Application.Rows[0][8]; MemoryStream Stream = new MemoryStream(); Stream.Write(image, 0, image.Length); Bitmap Display_Picture = new Bitmap(Stream); Image_Box.Image = Display_Picture; it works perfectly fine but if i update this with my own generated Query like System.IO.MemoryStream ms = new System.IO.MemoryStream(); Image img = Image_Box.Image; img.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp); Query = "UPDATE Person SET Person_Image ='"+ms.GetBuffer()+"' WHERE (Person_NIC = '"+NIC_Box.Text.Trim()+"')"; the next time i use the same code for retrieving the image and displaying it as used above . Program throws an exception

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  • Converting TrueClass / FalseClass to integer.

    - by Nick Gorbikoff
    Hello. I'm trying to figure out if there is an easy way to do the following short of adding to_i method to TrueClass/FalseClass. Here is a dilemma: I have a boolean field in my rails app - that is obviously stored as Tinyint in mysql. However - I need to generate xml based of the data in mysql and send it to customer - there SOAP service requires the field in question to have 0 or 1 as the value of this field. So at the time of the xml generation I need to convert my False to 0 and my True to 1 ( which is how they are stored in the DB). Since True & False lack to_i method I could write some if statement that generate either 1 or 0 depending on true/false state. However I have about 10 of these indicators and creating and if/else for each is not very DRY. So what you recommend I do? Or I could add a to_i method to the True / False class. But I'm not sure where should I scope it in my rails app? Just inside this particular model or somewhere else?

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  • KD-Trees and missing values (vector comparison)

    - by labratmatt
    I have a system that stores vectors and allows a user to find the n most similar vectors to the user's query vector. That is, a user submits a vector (I call it a query vector) and my system spits out "here are the n most similar vectors." I generate the similar vectors using a KD-Tree and everything works well, but I want to do more. I want to present a list of the n most similar vectors even if the user doesn't submit a complete vector (a vector with missing values). That is, if a user submits a vector with three dimensions, I still want to find the n nearest vectors (stored vectors are of 11 dimensions) I have stored. I have a couple of obvious solutions, but I'm not sure either one seem very good: Create multiple KD-Trees each built using the most popular subset of dimensions a user will search for. That is, if a user submits a query vector of thee dimensions, x, y, z, I match that query to my already built KD-Tree which only contains vectors of three dimensions, x, y, z. Ignore KD-Trees when a user submits a query vector with missing values and compare the query vector to the vectors (stored in a table in a DB) one by one using something like a dot product. This has to be a common problem, any suggestions? Thanks for the help.

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  • Is this the right way to organize my database tables?

    - by Moss
    So I'm making a website that allows users to build contact lists. So their are users, the users have lists, and the lists have contacts. It seems to me that I need 3 tables for this but I just want to make sure. There would be a User table of course, and then a "List of Lists" table that has the username, and listname, as primary key along with whatever other info we want to attach to the lists as a whole. Finally, for lack of a better word, the List table which would again have the username/listname p.k., then the contact ID and notes and such that the user attaches to that contact on that specific list. I hope that is a clear explanation. For some reason I feel unsure about this arrangement. For one thing if the website becomes popular the List table could swell to billions of rows. And it also feels a little weird that everybody's list info is all jumbled up in the same table. I suppose I could create separate tables for each user and even for each list but that seems like a bad idea for other reasons. My db explanation assumes I can use foreign keys on my tables which at the moment isn't actually an option. If I can't get InnoDB tables enabled I will probably use ID's for the lists instead of depending on a compound key. Maybe I should do this anyway?

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  • C++ : Avoid lot of boolean variable for multiple verification conditions in trading app

    - by Naveen
    Hi i am a junior dev in trading app... we have a order refresh verification unit. It has to verify order confirmation from exchange. We send a bunch of different request in bulk ( NEW, MODIFY, CANCEL ) to exchange... Verification has to happen for max N times with each T intervals for all orders. if verification successful for all the order before N retry then fine.. otherwise we need to indicate as verification unsuccessfull. i hv done a basic coding done in very urgent like below for( N times ) { for_each ( sent_request_order ) // SENT { 1) get all the refreshed order from DB or shared mem i.e REFRESHED 2) find current sent order in REFRESHED if( not_found ) not refreshed from exchange, continue to next order if( found ) case NEW : //check for new status, mark verification done case MODIFY : //check for modified status.. //if not mark pending, go to next order, //revisit the same after T time case CANCEL : //check for cancelled status.. //if not mark pending, go to next order, //revisit the same after T time } if( all_verified ) exit from verification. wait ( T sec ) } order_verification_pending, order_verification_done, order_visited, order_not_visited, all_verified, all_not_verified ... lot of boolean flags used for indication.. is there any better approach for doing this.... splitting responsibilities across the classes......???? i know this is not a general question.... but still flags are making me tidious to handle...

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  • dynamically created controls and responding to control events

    - by Dirk
    I'm working on an ASP.NET project in which the vast majority of the forms are generated dynamically at run time (form definitions are stored in a DB for customizability). Therefore, I have to dynamically create and add my controls to the Page every time OnLoad fires, regardless of IsPostBack. This has been working just fine and .NET takes care of managing ViewState for these controls. protected override void OnLoad(EventArgs e) { base.OnLoad(e); RenderDynamicControls() } private void RenderDynamicControls(){ //1. call service layer to retrieve form definition //2. create and add controls to page container } I have a new requirement in which if a user clicks on a given button (this button is created at design time) the page should be re-rendered in a slightly different way. So in addition to the code that executes in OnLoad (i.e. RenderDynamicControls()), I have this code: protected void MyButton_Click(object sender, EventArgs e) { RenderDynamicControlsALittleDifferently() } private void RenderDynamicControlsALittleDifferently() (){ //1. clear all controls from the page container added in RenderDynamicControls() //2. call service layer to retrieve form definition //3. create and add controls to page container } My question is, is this really the only way to accomplish what I'm after? It seems beyond hacky to effectively render the form twice simply to respond to a button click. I gather from my research that this is simply how the page-lifecycle works in ASP.NET: Namely, that OnLoad must fire on every Postback before child events are invoked. Still, it's worthwhile to check with the SO community before having to drink the kool-aid. On a related note, once I get this feature completed, I'm planning on throwing an UpdatePanel on the page to perform the page updates via Ajax. Any code/advice that make that transition easier would be much appreciated. Thanks

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  • Castle Active Record - Working with the cache

    - by David
    Hi All, im new to the Castle Active Record Pattern and Im trying to get my head around how to effectivley use cache. So what im trying to do (or want to do) is when calling the GetAll, find out if I have called it before and check the cache, else load it, but I also want to pass a bool paramter that will force the cache to clear and requery the db. So Im just looking for the final bits. thanks public static List<Model.Resource> GetAll(bool forceReload) { List<Model.Resource> resources = new List<Model.Resource>(); //Request to force reload if (forceReload) { //need to specify to force a reload (how?) XmlConfigurationSource source = new XmlConfigurationSource("appconfig.xml"); ActiveRecordStarter.Initialize(source, typeof(Model.Resource)); resources = Model.Resource.FindAll().ToList(); } else { //Check the cache somehow and return the cache? } return resources; } public static List<Model.Resource> GetAll() { return GetAll(false); }

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  • Important question about linq to SQL performance on high loaded web applications

    - by Alex
    I started working with linq to SQL several weeks ago. I got really tired of working with SQL server directly through the SQL queries (sqldatareader, sqlcommand and all this good stuff).  After hearing about linq to SQL and mvc I quickly moved all my projects to these technologies. I expected linq to SQL work slower but it suprisongly turned out to be pretty fast, primarily because I always forgot to close my connections when using datareaders. Now I don't have to worry about it. But there's one problem that really bothers me. There's one page that's requested thousands of times a day. The system gets data in the beginning, works with it and updates it. Primarily the updates are ++ @ -- (increase and decrease values). I used to do it like this UPDATE table SET value=value+1 WHERE ID=@I'd It worked with no problems obviously. But with linq to SQL the data is taken in the beginning, moved to the class, changed and then saved. Stats.registeredusers++; Db.submitchanges(); Let's say there were 100 000 users. Linq will say "let it be 100 001" instead of "let it be increased by 1". But if there value of users has already been increased (that happens in my site all the time) then linq will be like oops, this value is already 100 001. Whatever I'll throw an exception" You can change this behavior so that it won't throw an exception but it still will not set the value to 100 002. Like I said, it happened with me all the time. The stas value was increased twice a second on average. I simply had to rewrite this chunk of code with classic ado net. So my question is how can you solve the problem with linq

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  • Unknown user 'app' with capistrano

    - by trobrock
    This is my first time trying to set up capistrano to deploy a rails application. I am deploying from my local machine to my remote server that has the repo, web, app, and mysql servers all on the same machine. I am following this walk through: http://www.capify.org/index.php/From_The_Beginning I get to the command cap deploy:start Then I get this error: *** [err :: example.com] sudo: unknown user: app command finished failed: "sh -c 'cd /var/www/example/current && sudo -p '\\''sudo password: '\\'' -u app nohup script/spin'" on example.com Am I supposed to add an 'app' user, or is there a way of changing what user the command runs as? This is my deploy.rb: set :application, "example" set :repository, "[email protected]:example.git" set :user, "trobrock" set :branch, 'master' set :deploy_to, "/var/www/example" set :scm, :git # Or: `accurev`, `bzr`, `cvs`, `darcs`, `git`, `mercurial`, `perforce`, `subversion` or `none` role :web, "example.com" # Your HTTP server, Apache/etc role :app, "example.com" # This may be the same as your `Web` server role :db, "example.com", :primary => true # This is where Rails migrations will run And obviously everywhere it says example.com is my servers hostname and every it just says example is the app name.

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  • SQL Server 2008 - Shrinking the Transaction Log - Any way to automate?

    - by Albert
    I went in and checked my Transaction log the other day and it was something crazy like 15GB. I ran the following code: USE mydb GO BACKUP LOG mydb WITH TRUNCATE_ONLY GO DBCC SHRINKFILE(mydb_log,8) GO Which worked fine, shrank it down to 8MB...but the DB in question is a Log Shipping Publisher, and the log is already back up to some 500MB and growing quick. Is there any way to automate this log shrinking, outside of creating a custom "Execute T-SQL Statement Task" Maintenance Plan Task, and hooking it on to my log backup task? If that's the best way then fine...but I was just thinking that SQL Server would have a better way of dealing with this. I thought it was supposed to shrink automatically whenever you took a log backup, but that's not happening (perhaps because of my log shipping, I don't know). Here's my current backup plan: Full backups every night Transaction log backups once a day, late morning (maybe hook the Log shrinking onto this...doesn't need to be shrank every day though) Or maybe I just run it once a week, after I run a full backup task? What do you all think?

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  • spring 3 uploadify giving 404 Error

    - by Rajkumar
    I am using Spring 3 and implementing Uploadify. The problem is, the files are updating properly but it is giving HTTP Error 404, on completion of file upload. I tried every possible solution, but none of them works. The files are uploaded. Values are storing in DB properly, only that i am getting HTTP Error 404. Any help is appreciated and Thanks in advance. The JSP Page $(function() { $('#file_upload').uploadify({ 'swf' : 'scripts/uploadify.swf', 'fileObjName' : 'the_file', 'fileTypeExts' : '*.gif; *.jpg; *.jpeg; *.png', 'multi' : true, 'uploader' : '/photo/savePhoto', 'fileSizeLimit' : '10MB', 'uploadLimit' : 50, 'onUploadStart' : function(file) { $('#file_upload').uploadify('settings', 'formData', {'trip_id' :'1', 'trip_name' :'Sample Trip', 'destination_trip' :'Mumbai','user_id' :'1','email' :'[email protected]','city_id' :'12'}); }, 'onQueueComplete' : function(queueData) { console.log('queueData : '+queueData); window.location.href = "trip/details/1"; } }); }); The Controller @RequestMapping(value="photo/{action}", method=RequestMethod.POST) public String postHandler(@PathVariable("action") String action, HttpServletRequest request) { if(action.equals("savePhoto")) { try{ MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest)request; MultipartFile file = multipartRequest.getFile("the_file"); String trip_id = request.getParameter("trip_id"); String trip_name = request.getParameter("trip_name"); String destination_trip = request.getParameter("destination_trip"); String user_id = request.getParameter("user_id"); String email = request.getParameter("email"); String city_id = request.getParameter("city_id"); photo.savePhoto(file,trip_id,trip_name,destination_trip,user_id,email,city_id); photo.updatetrip(photo_id,trip_id); }catch(Exception e ){e.printStackTrace();} } return ""; } spring config <bean class="org.springframework.web.multipart.commons.CommonsMultipartResolver" id="multipartResolver"> <property name="maxUploadSize" value="10000000"/> </bean>

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  • t-sql most efficient row to column? crosstab for xml path, pivot

    - by ajberry
    I am looking for the most performant way to turn rows into columns. I have a requirement to output the contents of the db (not actual schema below, but concept is similar) in both fixed width and delimited formats. The below FOR XML PATH query gives me the result I want, but when dealing with anything other than small amounts of data, can take awhile. select orderid ,REPLACE(( SELECT ' ' + CAST(ProductId as varchar) FROM _details d WHERE d.OrderId = o.OrderId ORDER BY d.OrderId,d.DetailId FOR XML PATH('') ),'&#x20;','') as Products from _orders o I've looked at pivot but most of the examples I have found are aggregating information. I just want to combine the child rows and tack them onto the parent. I should also point out I don't need to deal with the column names either since the output of the child rows will either be a fixed width string or a delimited string. For example, given the following tables: OrderId CustomerId ----------- ----------- 1 1 2 2 3 3 DetailId OrderId ProductId ----------- ----------- ----------- 1 1 100 2 1 158 3 1 234 4 2 125 5 3 101 6 3 105 7 3 212 8 3 250 for an order I need to output: orderid Products ----------- ----------------------- 1 100 158 234 2 125 3 101 105 212 250 or orderid Products ----------- ----------------------- 1 100|158|234 2 125 3 101|105|212|250 Thoughts or suggestions? I am using SQL Server 2k5. Example Setup: create table _orders ( OrderId int identity(1,1) primary key nonclustered ,CustomerId int ) create table _details ( DetailId int identity(1,1) primary key nonclustered ,OrderId int ,ProductId int ) insert into _orders (CustomerId) select 1 union select 2 union select 3 insert into _details (OrderId,ProductId) select 1,100 union select 1,158 union select 1,234 union select 2,125 union select 3,105 union select 3,101 union select 3,212 union select 3,250 using FOR XML PATH: select orderid ,REPLACE(( SELECT ' ' + CAST(ProductId as varchar) FROM _details d WHERE d.OrderId = o.OrderId ORDER BY d.OrderId,d.DetailId FOR XML PATH('') ),'&#x20;','') as Products from _orders o which outputs what I want, however is very slow for large amounts of data. One of the child tables is over 2 million rows, pushing the processing time out to ~ 4 hours. orderid Products ----------- ----------------------- 1 100 158 234 2 125 3 101 105 212 250

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  • Entity Framework 4 overwrite Equals and GetHashCode of an own class property

    - by Zhok
    Hi, I’m using Visual Studio 2010 with .NET 4 and Entity Framework 4. I’m working with POCO Classes and not the EF4 Generator. I need to overwrite the Equals() and GetHashCode() Method but that doesn’t really work. Thought it’s something everybody does but I don’t find anything about the problem Online. When I write my own Classes and Equals Method, I use Equals() of property’s, witch need to be loaded by EF to be filled. Like this: public class Item { public virtual int Id { get; set; } public virtual String Name { get; set; } public virtual List<UserItem> UserItems { get; set; } public virtual ItemType ItemType { get; set; } public override bool Equals(object obj) { Item item = obj as Item; if (obj == null) { return false; } return item.Name.Equals(this.Name) && item.ItemType.Equals(this.ItemType); } public override int GetHashCode() { return this.Name.GetHashCode() ^ this.ItemType.GetHashCode(); } } That Code doesn’t work, the problems are in Equals and GetHashCode where I try to get HashCode or Equal from “ItemType” . Every time I get a NullRefernceException if I try to get data by Linq2Entites. A dirty way to fix it, is to capture the NullReferenceException and return false (by Equals) and return base.GetHashCode() (by GethashCode) but I hope there is a better way to fix this problem. I’ve wrote a little test project, with SQL Script for the DB and POCO Domain, EDMX File and Console Test Main Method. You can download it here: Download

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  • Beginner's guide for rails

    - by piemesons
    Hello friends i need a book/ tutorials for rails without using scoffold. All the books mentioned in the other questions are creating some depot application or etc using scaffold and then explaining things. I believe in the thing that creating big depot is worthless when you are not getting anything. All of my frnds are suggesting me to go for this pragmatic book. look i understand the book is good but i m not getting the proper things. I got the logic cause i m good in php doctrine. asp.net c c++ so i m getting the things but i m not feeling confident. I want to have a another book. Can anybody suggest me some other books. I m saying this cause it really feels good when u create a simple form and insert the values in db and u can retreive those values and MOST IMP you can explain the whole logic of the that small form application instaed of that colorfull Depot application in which things are done with scaffold and u r not getting the thing and u are confused abt the real picture.

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  • security deleting a mysql row with jQuery $.post

    - by FFish
    I want to delete a row in my database and found an example on how to do this with jQuery's $.post() Now I am wondering about security though.. Can someone send a POST request to my delete-row.php script from another website? JS function deleterow(id) { // alert(typeof(id)); // number if (confirm('Are you sure want to delete?')) { $.post('delete-row.php', {album_id:+id, ajax:'true'}, function() { $("#row_"+id).fadeOut("slow"); }); } } PHP: delete-row.php <?php require_once("../db.php"); mysql_connect(DB_SERVER, DB_USER, DB_PASSWORD) or die("could not connect to database " . mysql_error()); mysql_select_db(DB_NAME) or die("could not select database " . mysql_error()); if (isset($_POST['album_id'])) { $query = "DELETE FROM albums WHERE album_id = " . $_POST['album_id']; $result = mysql_query($query); if (!$result) die('Invalid query: ' . mysql_error()); echo "album deleted!"; } ?>

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  • Maintaining a pool of DAO Class instances vs doing new operator

    - by Fazal
    we have been trying to benchmark our application performance in multiple way for sometime now. I always believed that object creation in java using Class.newInstance() was not slow (at least after 1.4 version of java). But we anyways did a test to use newInstance method vs mainitain an object pool of 1000 objects. We did about 200K iterations of loading data from DB using JDBC and populating these objects. I was amazed (even shocked) to see that newInstance code compared to object pool code was almost 10 times slower. These objects represent tables with about 50 fields and all string type. Can someone share there thoughts on this issue as now I am more confused if object pooling of atleast some DAO instances is a better option. The pool size as I see right now should be large enough to meet size of average requests. There is a flip side as my memory footprint will go up but I am beginning to wonder if this kind of idea makes sense atleast for some of the DAO entities representing tables of about 50 or more columns Please share your ideas and let me know if this has been tried by someone or am I missing some point here

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  • Preventing a button from responding to 'Enter' in ASP.net

    - by kd7iwp
    I have a master template that all the pages on my site use. In the template there is an empty panel. In the code-behind for the page an imagebutton is created in the panel dynamically in my Page_Load section (makes a call to the DB to determine which button should appear via my controller). On some pages that use this template and have forms on them, pressing the Enter key fires the click event on this imagebutton rather than the submit button in the form. Is there a simple way to prevent the imagebutton click event from firing unless it's clicked by the mouse? I'm thinking a javascript method is a hack, especially since the button doesn't even exist in the master template until the button is dynamically created on Page_Load (this is ugly since I can't simply do <% =btnName.ClientId %> to refer to the button's name in my aspx page). I tried setting a super-high tabindex for the image button and that did nothing. Also set the button to be the DefaultButton in its panel on the master template but that did not work either.

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  • Creating self-referential tables with polymorphism in SQLALchemy

    - by Jace
    I'm trying to create a db structure in which I have many types of content entities, of which one, a Comment, can be attached to any other. Consider the following: from datetime import datetime from sqlalchemy import create_engine from sqlalchemy import Column, ForeignKey from sqlalchemy import Unicode, Integer, DateTime from sqlalchemy.orm import relation, backref from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class Entity(Base): __tablename__ = 'entities' id = Column(Integer, primary_key=True) created_at = Column(DateTime, default=datetime.utcnow, nullable=False) edited_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False) type = Column(Unicode(20), nullable=False) __mapper_args__ = {'polymorphic_on': type} # <...insert some models based on Entity...> class Comment(Entity): __tablename__ = 'comments' __mapper_args__ = {'polymorphic_identity': u'comment'} id = Column(None, ForeignKey('entities.id'), primary_key=True) _idref = relation(Entity, foreign_keys=id, primaryjoin=id == Entity.id) attached_to_id = Column(Integer, ForeignKey('entities.id'), nullable=False) #attached_to = relation(Entity, remote_side=[Entity.id]) attached_to = relation(Entity, foreign_keys=attached_to_id, primaryjoin=attached_to_id == Entity.id, backref=backref('comments', cascade="all, delete-orphan")) text = Column(Unicode(255), nullable=False) engine = create_engine('sqlite://', echo=True) Base.metadata.bind = engine Base.metadata.create_all(engine) This seems about right, except SQLAlchemy doesn't like having two foreign keys pointing to the same parent. It says ArgumentError: Can't determine join between 'entities' and 'comments'; tables have more than one foreign key constraint relationship between them. Please specify the 'onclause' of this join explicitly. How do I specify onclause?

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  • RavenDB Ids and ASP.NET MVC3 Routes

    - by goober
    Hey all, Just building a quick, simple site with MVC 3 RC2 and RavenDB to test some things out. I've been able to make a bunch of projects, but I'm curious as to how Html.ActionLink() handles a raven DB ID. My example: I have a Document called "reasons" (a reason for something, just text mostly), which has reason text and a list of links. I can add, remove, and do everything else fine via my repository. Below is the part of my razor view that lists each reason in a bulleted list, with an Edit link as the first text: @foreach(var Reason in ViewBag.ReasonsList) { <li>@Html.ActionLink("Edit", "Reasons", "Edit", new { id = Reason.Id }, null) @Reason.ReasonText</li> <ul> @foreach (var reasonlink in Reason.ReasonLinks) { <li><a href="@reasonlink.URL">@reasonlink.URL</a></li> } </ul> } The Problem This works fine, except for the edit link. While the values and code here appear to work directly (i.e the link is firing directly), RavenDB saves my document's ID as "reasons/1". So, when the URL happens and it passes the ID, the resulting route is "http://localhost:4976/Reasons/Edit/reasons/2". So, the ID is appended correctly, but MVC is interpreting it as its own route. Any suggestions on how I might be able to get around this? Do I need to create a special route to handle it or is there something else I can do?

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  • Re-use of database object in sub-sonic

    - by cantabilesoftware
    Yet another newbie SubSonic/ActiveRecord question. Suppose I want to insert a couple of records, currently I'm doing this: using (var scope = new System.Transactions.TransactionScope()) { // Insert company company c = new company(); c.name = "ACME"; c.Save(); // Insert some options company_option o = new company_option(); o.name = "ColorScheme"; o.value = "Red"; o.company_id = c.company_id; o.Save(); o = new company_option(); o.name = "PreferredMode"; o.value = "Fast"; o.company_id = c.company_id; o.Save(); scope.Complete(); } Stepping through this code however, each of the company/company_option constructors go off and create a new myappDB object which just seems wasteful. Is this the recommended approach or should I be trying to re-use a single DB object - and if so, what's the easiest way to do this?

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  • Finding the right terminology for a dictionary table

    - by Karl Forner
    My concern is about what I currently call "dictionary tables", that are database tables containing a list of controlled vocabulary. Let's use an example: Suppose you have a table User containing fields: user_id : primary key first_name last_name user_type_id : foreign key to the UserType table and another table UserType with just two fields: user_type_id : primary key name : the name/value of a particular type of user. For instance, the UserType table may contain (1, Administrator), (2, PowerUser), (3, Normal)... My question is: what is the canonical term for a table like UserType, that only contains a list of (dictinct) words. I want to publish some code that help managing this kind of tables, but first I have to name them ! Thanks for your help. Current state of thought: For now I feel Lookup Tables is a good term. It is also used with the same meaning in these posts: http://dbix-class.35028.n2.nabble.com/RFC-Component-for-Lookup-tables-td3504085.html http://tonyandrews.blogspot.de/2004/10/otlt-and-eav-two-big-design-mistakes.html Lookup Tables Best Practices: DB Tables... or Enumerations The only problem is that lookup table is also sometimes used to name a junction table.

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  • How should I design my MYSQL table/s?

    - by yaya3
    I built a really basic php/mysql site for an architect that uses one 'projects' table. The website showcases various projects that he has worked on. Each project contained one piece of text and one series of images. Original projects table (create syntax): CREATE TABLE `projects` ( `project_id` int(11) NOT NULL auto_increment, `project_name` text, `project_text` text, `image_filenames` text, `image_folder` text, `project_pdf` text, PRIMARY KEY (`project_id`) ) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=latin1; The client now requires the following, and I'm not sure how to handle the expansions in my DB. My suspicion is that I will need an additional table. Each project now have 'pages'. Pages either contain... One image One "piece" of text One image and one piece of text. Each page could use one of three layouts. As each project does not currently have more than 4 pieces of text (a very risky assumption) I have expanded the original table to accommodate everything. New projects table attempt (create syntax): CREATE TABLE `projects` ( `project_id` int(11) NOT NULL AUTO_INCREMENT, `project_name` text, `project_pdf` text, `project_image_folder` text, `project_img_filenames` text, `pages_with_text` text, `pages_without_img` text, `pages_layout_type` text, `pages_title` text, `page_text_a` text, `page_text_b` text, `page_text_c` text, `page_text_d` text, PRIMARY KEY (`project_id`) ) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=latin1; In trying to learn more about MYSQL table structuring I have just read an intro to normalization and A Simple Guide to Five Normal Forms in Relational Database Theory. I'm going to keep reading! Thanks in advance

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  • EF Forced Concurrency Checks

    - by Imran
    Hi, I have an issue with EF 4.0 that I hope someone can help with. I currently have an entity that I want to update in a last in wins fashion (i.e. ignore concurrency checks and just overwrite whats in the db with what is submitted). It seems Entity Framework not only includes the primary key of the entity in the where clause of the generated sql, but also any foreign key fields. This is annoying as it means that I don't get true last in wins semantics and need to know what value the fk field had before the update or I get a concurrency exception. I am aware that this can be short circuited by including a foreign key field as well as the navigation property on the entity. I would like to avoid this if possible as it's not a very clean solution. I was just wondering if there was any other way to override this behaviour? It seems like more of a bug than a feature. I have no problem with ef doing concurrency checks if I instruct it to do so but not being able to bypass concurrency completely is a bit of a hindrance as there are many valid scenarios where this is not needed

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  • How to use SQLErrorCodeSQLExceptionTranslator and DAO class with @Repository in Spring?

    - by GuidoMB
    I'm using Spring 3.0.2 and I have a class called MovieDAO that uses JDBC to handle the db. I have set the @Repository annotations and I want to convert the SQLException to the Spring's DataAccessException I have the following example: @Repository public class JDBCCommentDAO implements CommentDAO { static JDBCCommentDAO instance; ConnectionManager connectionManager; private JDBCCommentDAO() { connectionManager = new ConnectionManager("org.postgresql.Driver", "postgres", "postgres"); } static public synchronized JDBCCommentDAO getInstance() { if (instance == null) instance = new JDBCCommentDAO(); return instance; } @Override public Collection<Comment> getComments(User user) throws DAOException { Collection<Comment> comments = new ArrayList<Comment>(); try { String query = "SELECT * FROM Comments WHERE Comments.userId = ?"; Connection conn = connectionManager.getConnection(); PreparedStatement stmt = conn.prepareStatement(query); stmt = conn.prepareStatement(query); stmt.setInt(1, user.getId()); ResultSet result = stmt.executeQuery(); while (result.next()) { Movie movie = JDBCMovieDAO.getInstance().getLightMovie(result.getInt("movie")); comments.add(new Comment(result.getString("text"), result.getInt("score"), user, result.getDate("date"), movie)); } connectionManager.closeConnection(conn); } catch (SQLException e) { e.printStackTrace(); //CONVERT TO DATAACCESSEXCEPTION } return comments; } } I Don't know how to get the Translator and I don't want to extends any Spring class, because that is why I'm using the @Repository annotation

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  • Translating Where() to sql

    - by MBoros
    Hi. I saw DamienG's article (http://damieng.com/blog/2009/06/24/client-side-properties-and-any-remote-linq-provider) in how to map client properties to sql. i ran throgh this article, and i saw great potential in it. Definitely mapping client properties to SQL is an awesome idea. But i wanted to use this for something a bit more complicated then just concatenating strings. Atm we are trying to introduce multilinguality to our Business objects, and i hoped we could leave all the existing linq2sql queries intact, and just change the code of the multilingual properties, so they would actually return the given property in the CurrentUICulture. The first idea was to change these fields to XMLs, and then try the Object.Property.Elements().Where(...), but it got stuck on the Elements(), as it couldnt translate it to sql. I read somewhere that XML fields are actually regarded as strings, and only on the app server they become XElements, so this way the filtering would be on the app server anyways, not the DB. Fair point, it wont work like this. Lets try something else... SO the second idea was to create a PolyGlots table (name taken from http://weblogic.sys-con.com/node/102698?page=0,1), a PolyGlotTranslations table and a Culture table, where the PolyGlots would be referenced from each internationalized property. This way i wanted to say for example: private static readonly CompiledExpression<Announcement, string> nameExpression = DefaultTranslationOf<Announcement> .Property(e => e.Name) .Is(e=> e.NamePolyGlot.PolyGlotTranslations .Where(t=> t.Culture.Code == Thread.CurrentThread.CurrentUICulture.Name) .Single().Value ); now unfortunately here i get an error that the Where() function cannot be translated to sql, what is a bit disappointing, as i was sure it will go through. I guess it is failing, cause the IEntitySet is basically an IEnumerable, not IQueryable, am i right? Is there another way to use the compiledExpressions class to achieve this goal? Any help appreciated.

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