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  • DataReader already open when using LINQ

    - by Jamie Dixon
    I've got a static class containing a static field which makes reference to a wrapper object of a DataContext. The DataContext is basically generated by Visual Studio when we created a dbml file & contains methods for each of the stored procedures we have in the DB. Our class basically has a bunch of static methods that fire off each of these stored proc methods & then returns an array based on a LINQ query. Example: public static TwoFieldBarData[] GetAgesReportData(string pct) { return DataContext .BreakdownOfUsersByAge(Constants.USER_MEDICAL_PROFILE_KEY, pct) .Select(x => new TwoFieldBarData(x.DisplayName, x.LeftValue, x.RightValue, x.TotalCount)) .ToArray(); } Every now and then, we get the following error: There is already an open DataReader associated with this Command which must be closed firs This is happening intermittently and I'm curious as to what is going on. My guess is that when there's some lag between one method executing and the next one firing, it's locking up the DataContext and throwing the error. Could this be a case for wrapping each of the DataContext LINQ calls in a lock(){} to obtain exclusivity to that type and ensure other requests are queued?

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  • Lost with hibernate - OneToMany resulting in the one being pulled back many times..

    - by Andy
    I have this DB design: CREATE TABLE report ( ID MEDIUMINT PRIMARY KEY NOT NULL AUTO_INCREMENT, user MEDIUMINT NOT NULL, created TIMESTAMP NOT NULL, state INT NOT NULL, FOREIGN KEY (user) REFERENCES user(ID) ON UPDATE CASCADE ON DELETE CASCADE ); CREATE TABLE reportProperties ( ID MEDIUMINT NOT NULL, k VARCHAR(128) NOT NULL, v TEXT NOT NULL, PRIMARY KEY( ID, k ), FOREIGN KEY (ID) REFERENCES report(ID) ON UPDATE CASCADE ON DELETE CASCADE ); and this Hibernate Markup: @Table(name="report") @Entity(name="ReportEntity") public class ReportEntity extends Report{ @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name="ID") private Integer ID; @Column(name="user") private Integer user; @Column(name="created") private Timestamp created; @Column(name="state") private Integer state = ReportState.RUNNING.getLevel(); @OneToMany(mappedBy="pk.ID", fetch=FetchType.EAGER) @JoinColumns( @JoinColumn(name="ID", referencedColumnName="ID") ) @MapKey(name="pk.key") private Map<String, ReportPropertyEntity> reportProperties = new HashMap<String, ReportPropertyEntity>(); } and @Table(name="reportProperties") @Entity(name="ReportPropertyEntity") public class ReportPropertyEntity extends ReportProperty{ @Embeddable public static class ReportPropertyEntityPk implements Serializable{ /** * long#serialVersionUID */ private static final long serialVersionUID = 2545373078182672152L; @Column(name="ID") protected int ID; @Column(name="k") protected String key; } @EmbeddedId protected ReportPropertyEntityPk pk = new ReportPropertyEntityPk(); @Column(name="v") protected String value; } And i have inserted on Report and 4 Properties for that report. Now when i execute this: this.findByCriteria( Order.asc("created"), Restrictions.eq("user", user.getObject(UserField.ID)) ) ); I get back the report 4 times, instead of just the once with a Map with the 4 properties in. I'm not great at Hibernate to be honest, prefer straight SQL but I must learn, but i can't see what it is that is wrong.....? Any suggestions?

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  • Passing arguments and values from HTML to jQuery (events)

    - by Jaroslav Moravec
    What is the practice to pass arguments from HTML to jQuery events function. For example getting id of row from db: <tr class="jq_killMe" id="thisItemId-id"> ... </tr> and jQuery: $(".jq_killMe").click(function () { var tmp = $(this).attr('id).split("-"); var id = tmp[0] // ... } What's the best practise, if I want to pass more than one argument? Is it better not to use jQuery? For example: <tr onclick="killMe('id')"> ... </tr> I didn't find the answer on my question, I will be glad even for links. Thanks. Edit (pre solution) So you suggested two methods to do that: Add custom attributes to element (XHTML) Use attribute ID and parse it by regex Attribute data-* attributes in HTML5 Use hidden children elements I like first solution, but... I would like to (I have to (employer)) produce valid code. Here is a nice question and answers: http://stackoverflow.com/questions/994856/so-what-if-custom-html-attributes-arent-valid-xhtml And the second is not so pretty as the first, but valid. So the compromise is... The third is the solution for future, but here is a lot of CMS where we have to use XHTML or HTML4. (And HTML5 is the long process)

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  • How to submit Nothing as a route value to ASP MVC

    - by Adam
    I have a route with several optional parameters. These are possible search terms in different fields. So, for example, if I have fields key, itemtype and text then I have in global.asax: routes.MapRoute( _ "Search", _ "Admin.aspx/Search/{Key}/{ItemType}/{Text}", _ New With {.controller = "Admin", .action = "Search" .Key = Nothing, .ItemType = Nothing, .Text = Nothing} _ ) My action takes optional parameters: Function Search(Optional ByVal Key As String = Nothing, _ Optional ByVal ItemType As Integer = 0, _ Optional ByVal Text As String = Nothing, _ Optional ByVal OtherText As String = Nothing) It then checks if the Key and Text strings have a non-null (and non-empty) value and adds search terms to the db request as needed. However, is it possible to send in a null value for, for example, Key but still send in a value for Text? If so, what does the URL look like? (Admin.aspx/Search//0/Foo doesn't work :) ) I know I can handle this using a parameter array instead, but wondered if this was possible using the sort of route described? I could of course define some other value as equivalent to null (for example, a space/%20) but is there any way to send a null value in the URL? I'm suspecting not, but thought I'd see if anyone knew of one. I'm using ASP MVC 2 for this project.

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  • Building a custom CMS, how to handle page settings?

    - by davidosomething
    Not a coldfusion specific question so answer however you can. I've inherited a ColdFusion project where at the top of every page various page-setting specific variables are set, such as: <cfset request.page.title = "Example Page"> <cfset request.page.machineTitle = "example_page"> <cfset request.page.isJQueryEnabled = 1> <cfset request.page.showNavigation = 1> <cfset request.page.SWFObjectVersion = 2.2> I'm thinking about creating a database table with just integer page_id varchar key varchar value I'd reduce the variables at the top of every page to just the page id, and then call the DB for the correct settings. Is this a good idea? I hate reinventing the wheel, but this is a really big project that would require many months for a full content migration to a CMS. What are the current practices for storing page settings? (e.g., what does WordPress do? Drupal? etc.)

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  • need help fixing unique key in rails. rails is adding id causing duplicate key

    - by railsnew
    I need some help in fixing the below issue. I had transaction blocks in my rails code like below: @sqlcontact = "INSERT INTO contacts (id,\"cid\", \"hphone\", mphone, provider, cemail, email, sms , mail, phone) VALUES ('"+@id1+"','" + @id1 + "', '"+ params[:hphone] + "', '"+params[:mphone]+ "', '" + params[:provider] + "', '" + params[:cemail]+ "', '" + @varemail+ "', '"+@varsms+ "', '"+ @varmail+"', '"+@varphone+"')" my app was deployed to heroku so I was advised by them to remove transaction blocks. So I changed the above to: @cont = Contact.new(:id => @id1, :cid => @id1, :hphone => params[:hphone], :mphone => params[:mphone], :provider => params[:provider], :cemail => params[:cemail], :email => @varemail, :sms => @varsms, :mail => @varmail, :phone => @varphone) @cont.save My app also already had data stored. Now the problem is that when I try to save a record ...I keep getting the error: duplicate key value violates unique constraint "contacts_pkey" The error also shows the sql query trying to insert data ...however, in that sql query i Do not see id value. As you can see from my code that I am passing the id. then why is rails not accepting it? does it always include its own sequential id? can I not overwrite the default rails magic? and if it does that...does it not look at data that is already in the DB?? I am really stuck here. What should I do? should I just go back to my transaction block

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  • linq: 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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  • Hibernate noob fetch join problem

    - by Bruce
    Hi all I have two classes, Test2 and Test3. Test2 has an attribute test3 that is an instance of Test3. In other words, I have a unidirectional OneToOne association, with test2 having a reference to test3. When I select Test2 from the db, I can see that a separate select is being made to get the details of the associated test3 class. This is the famous 1+N selects problem. To fix this to use a single select, I am trying to use the fetch=join annotation, which I understand to be @Fetch(FetchMode.JOIN) However, with fetch set to join, I still see separate selects. Here are the relevant portions of my setup.. hibernate.cfg.xml: <property name="max_fetch_depth">2</property> Test2: public class Test2 { @OneToOne (cascade=CascadeType.ALL , fetch=FetchType.EAGER) @JoinColumn (name="test3_id") @Fetch(FetchMode.JOIN) public Test3 getTest3() { return test3; } NB I set the FetchType to EAGER out of desperation, even though it defaults to EAGER anyway for OneToOne mappings, but it made no difference. Thanks for any help! Edit: I've pretty much given up on trying to use FetchMode.JOIN - can anyone confirm that they have got it to work ie produce a left outer join? In the docs I see that "Usually, the mapping document is not used to customize fetching. Instead, we keep the default behavior, and override it for a particular transaction, using left join fetch in HQL" If I do a left join fetch instead: query = session.createQuery("from Test2 t2 left join fetch t2.test3"); then I do indeed get the results I want - ie a left outer join in the query.

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  • How to perform Rails model validation checks within model but outside of filters using ledermann-rails-settings and extensions

    - by user1277160
    Background I'm using ledermann-rails-settings (https://github.com/ledermann/rails-settings) on a Rails 2/3 project to extend virtually the model with certain attributes that don't necessarily need to be placed into the DB in a wide table and it's working out swimmingly for our needs. An additional reason I chose this Gem is because of the post How to create a form for the rails-settings plugin which ties ledermann-rails-settings more closely to the model for the purpose of clean form_for usage for administrator GUI support. It's a perfect solution for addressing form_for support although... Something that I'm running into now though is properly validating the dynamic getters/setters before being passed to the ledermann-rails-settings module. At the moment they are saved immediately, regardless if the model validation has actually fired - I can see through script/console that validation errors are being raised. Example For instance I would like to validate that the attribute :foo is within the range of 0..100 for decimal usage (or even a regex). I've found that with the previous post that I can use standard Rails validators (surprise, surprise) but I want to halt on actually saving any values until those are addressed - ensure that the user of the GUI has given 61.43 as a numerical value. The following code has been borrowed from the quoted post. class User < ActiveRecord::Base has_settings validates_inclusion_of :foo, :in => 0..100 def self.settings_attr_accessor(*args) >>SOME SORT OF UNLESS MODEL.VALID? CHECK HERE args.each do |method_name| eval " def #{method_name} self.settings.send(:#{method_name}) end def #{method_name}=(value) self.settings.send(:#{method_name}=, value) end " end >>END UNLESS end settings_attr_accessor :foo end Anyone have any thoughts here on pulling the state of the model at this point outside of having to put this into a before filter? The goal here is to be able to use the standard validations and avoid rolling custom validation checks for each new settings_attr_accessor that is added. Thanks!

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  • How do you filter a view of a DataTable in .Net 3.5 sp1 using WPF c# and xaml?

    - by Tony
    I found the MSDN example code for getting the default view of a collection and adding a filter to the view, but most of it is for .Net 4.0. I'm on a team that is not currently switching to 4.0, so I don't have that option. None of the examples I found used a DataTable as the source, so I had to adapt it a little. I'm using a DataTable because the data is comming from a DB ans it's easy to populate. After trying to implement the MSDN examples, I get a "NotSupportedException" when I try to set the Filter. This is the c# code I have: protected DataTable _data = new DataTable(); protected BindingListCollectionView _filteredDataView; ... private void On_Loaded(Object sender, RoutedEventArgs e) { _filteredDataView = (BindingListCollectionView)CollectionViewSource.GetDefaultView(_data); _filteredDataView.Filter = new Predicate(MatchesCurrentSelections); // throws NotSupportedException } ... public bool MatchesCurrentSelections(object o){...} It seems that either BindingListCollectionView does not support filtering in .Net 3.5, or it just doesn't work for a DataTable. I looked at setting it up in XAML instead of the C# code, but the XAML examples use collections in resources instead of a collection that is a memberof the class, so I have no idea how to set that up. Does any one know how to filter a view to a DataTable?

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  • Need to add WHERE condition to query

    - by Angel Carlson
    I am trying to modify edit_orders.php in Zen Cart. Hoping someone might be able to help me add a condition to a query. I need the queries below to specify that the items selected from TABLE_PRODUCTS_DESCRIPTION and TABLE_CATEGORIES_DESCRIPTION must have a language_id = 1. Would be so grateful for any help you could provide. // ############################################################################ // Get List of All Products // ############################################################################ //$result = zen_db_query("SELECT products_name, p.products_id, x.categories_name, ptc.categories_id FROM " . TABLE_PRODUCTS . " p LEFT JOIN " . TABLE_PRODUCTS_DESCRIPTION . " pd ON pd.products_id=p.products_id LEFT JOIN " . TABLE_PRODUCTS_TO_CATEGORIES . " ptc ON ptc.products_id=p.products_id LEFT JOIN " . TABLE_CATEGORIES_DESCRIPTION . " cd ON cd.categories_id=ptc.categories_id LEFT JOIN " . TABLE_CATEGORIES_DESCRIPTION . " x ON x.categories_id=ptc.categories_id ORDER BY categories_id"); $result = $db -> Execute("SELECT products_name, p.products_id, categories_name, ptc.categories_id FROM " . TABLE_PRODUCTS . " p LEFT JOIN " . TABLE_PRODUCTS_DESCRIPTION . " pd ON pd.products_id=p.products_id LEFT JOIN " . TABLE_PRODUCTS_TO_CATEGORIES . " ptc ON ptc.products_id=p.products_id LEFT JOIN " . TABLE_CATEGORIES_DESCRIPTION . " cd ON cd.categories_id=ptc.categories_id ORDER BY categories_name");

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  • php sessions in database only writing part of information to the table...

    - by Ronedog
    I'm having difficulty figuring out what's going on here, hoping some one can help me out. I have been using php, mysql storing my session information in the database. The app is only running on localhost, vista. In the php.ini file I commented out the "session.save_handler = files" line and am using a php class to handle the session writes/reads, etc. My login process is this: Submit login credentials via login.php. login.php calls loginprocess.php. loginprocess.php verifies user, and if valid starts a new session and adds data to the session vars, then it redirects to index.php. Here's the problem. the loginprocess.php page has a bunch of session vars that get set like $_SESSION['account_id'] = $account_id; etc. but when I go to index.php and do a var_dump($_SESSION) it just says "array() empty". However, if I do a var_dump($_SESSION) in loginprocess.php, just before the redirection line header("Location: ../index.php"); then it shows all the data in the session variable. If I look in the database where the session information is stored, there is data in the session_id field, created_ts field, and expires field, but the session_data field has nothing inside of it and in the past this is the field where all my session data was stored. How could I be able to var_dump the session in loginprocess.php, but the data not exist in the db table, is it using some kind of caching? I cleared my cookies, etc...but no change. Why is the session_id, being written to the table, but the actual session data is not? Any ideas are appreciated. Thanks.

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  • treeview dynamically populated

    - by Laziale
    Hello everyone - I have this treeview control where I want to put uploaded files on the server. I want to be able to create the nodes and the child nodes dynamically from the database. I am using this query for getting the data from DB: SELECT c.Category, d.DocumentName FROM Categories c INNER JOIN DocumentUserFile d ON c.ID = d.CategoryId WHERE d.UserId = '9rge333a-91b5-4521-b3e6-dfb49b45237c' The result from that query is this one: Agendas transactions.pdf Minutes accounts.pdf I want to have the treeview sorted that way too. I am trying with this piece of code: TreeNode tn = new TreeNode(); TreeNode tnSub = new TreeNode(); foreach (DataRow dt in tblTreeView.Rows) { tn.Text = dt[0].ToString(); tn.Value = dt[0].ToString(); tnSub.Text = dt[1].ToString(); tnSub.NavigateUrl = "../downloading.aspx?file=" + dt[1].ToString() +"&user=" + userID; tn.ChildNodes.Add(tnSub); tvDocuments.Nodes.Add(tn); } I am getting the treeview populated nicely for the 1st category and the document under that category, but I can't get it to work when I want to show more documents under that category, or even more complicate to show new category beneath the 1st one with documents from that category. How can I solve this? I appreciate the answers a lot. Thanks, Laziale

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  • Joining Tables Based on Foreign Keys

    - by maestrojed
    I have a table that has a lot of fields that are foreign keys referencing a related table. I am writing a script in PHP that will do the db queries. When I query this table for its data I need to know the values associated with these keys not the key. How do most people go about this? A 101 way to do this would be to query this table for its data including the foreign keys and then query the related tables to get each key's value. This could be a lot of queries (~10). Question 1: I think I could write 1 query with a bunch of joins. Would that be better? This approach also requires the querying script to know which table fields are foreign keys. Since I have many tables like this but all with different fields, this means writing nice generic functions is hard. MySQL InnoDB tables allow for foreign constraints. I know the database has these set up correctly. Question 2: What about the idea of querying the table and identifying what the constraints are and then matching them up using whatever process I decide on from Question 1. I like this idea but never see it being used in code. Makes me think its not a good idea for some reason. I would use something like SHOW CREATE TABLE tbl_name; to find what constraints/relationships exist for that table. Thank you for any suggestions or advice.

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  • Prevent Text Input expanding in IE

    - by Caroline
    Hi, I am having a problem with an input field in IE. The code is for a portlet and widths need to be dynamic as the user can place the portlet on any of the three columns in the page which all have different widths. As always it works fine in FF but not in IE. In order to make the width dyanaic I have set width="100%". Data to populate the text input comes from a DB. When the page is rendered if there is a long URL the text input expands to fill the contents in IE but in FF it just stays the same width (ie 100% of the TD that it lives in). How can I stop IE from changing the width in order to fit the contents. Setting the width to a fixed width of 100px fixes the issue but I need to have the width as a percentage in order to accommodate the layout of the portlet wherever it is put in on the page. I have tried overflow:hidden and word-wrap:break-word but I cant get either to work. Here is my input code and style sheets <td class="right" > <input type="text" class="validate[custom[url]]" value="" id="linkText" name="communicationLink" maxlength="500" maxsize="100" /> </td> .ofCommunicationsAdmin input { font-family: "Trebuchet MS"; font-size: 11px; font-weight:normal; color:#333333; overflow:hidden; } .ofCommunicationsAdmin #linkText { overflow:hidden; width:100%; border:1px #cccccc solid; background:#F4F7ED top repeat-x; } .ofCommunicationsAdmin td.right { vertical-align: top; text-align: left; }

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  • How can I log any login operation in case of "Remember Me" option ?

    - by Space Cracker
    I have an asp.net login web form that have ( username textBox - password textBox ) plus Remember Me CheckBox option When user login i do the below code if (provider.ValidateUser(username, password)) { int timeOut = 0x13; DateTime expireDate = DateTime.Now.AddMinutes(19.0); if (rememberMeCheckBox.Checked) { timeOut = 0x80520; expireDate = DateTime.Now.AddYears(1); } FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(username, true, timeOut); string cookieValue = FormsAuthentication.Encrypt(ticket); HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, cookieValue); cookie.Expires = expireDate; HttpContext.Current.Response.Cookies.Add(cookie); AddForLogin(username); Response.Redirect("..."); } as in code after user is authenticated i log that he login in db by calling method AddForLogin(username); But if user choose remember me in login and then he try to go to site any time this login method isn't executed as it use cookies ... so i have many questions: 1- Is this the best way to log login operation or is there any other better ? 2- In my case how to log login operation in case of remember me chosen by user ?

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  • Django: Filtering datetime field by *only* the year value?

    - by unclaimedbaggage
    Hi folks, I'm trying to spit out a django page which lists all entries by the year they were created. So, for example: 2010: Note 4 Note 5 Note 6 2009: Note 1 Note 2 Note 3 It's proving more difficult than I would have expected. The model from which the data comes is below: class Note(models.Model): business = models.ForeignKey(Business) note = models.TextField() created = models.DateTimeField(auto_now_add=True) updated = models.DateTimeField(auto_now=True) class Meta: db_table = 'client_note' @property def note_year(self): return self.created.strftime('%Y') def __unicode__(self): return '%s' % self.note I've tried a few different ways, but seem to run into hurdles down every path. I'm guessing an effective 'group by' method would do the trick (PostGres DB Backend), but I can't seem to find any Django functionality that supports it. I tried getting individual years from the database but I struggled to find a way of filtering datetime fields by just the year value. Finally, I tried adding the note_year @property but because it's derived, I can't filter those values. Any suggestions for an elegant way to do this? I figure it should be pretty straightforward, but I'm having a heckuva time with it. Any ideas much appreciated.

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  • How do I do MongoDB console-style queries in PHP?

    - by Zoe Boles
    I'm trying to get a MongoDB query from the javascript console into my PHP app. What I'm trying to avoid is having to translate the query into the PHP "native driver"'s format... I don't want to hand build arrays and hand-chain functions any more than I want to manually build an array of MySQL's internal query structure just to get data. I already have a string producing the exact content I want in the Mongo console: db.intake.find({"processed": {"$exists": "false"}}).sort({"insert_date": "1"}).limit(10); The question is, is there a way for me to hand this string, as is, to MongoDB and have it return a cursor with the dataset I request? Right now I'm at the "write your own parser because it's not valid json to kinda turn a subset of valid Mongo queries into the format the PHP native driver wants" state, which isn't very fun. I don't want an ORM or a massive wrapper library; I just want to give a function my query string as it exists in the console and get an Iterator back that I can work with. I know there are a couple of PHP-based Mongo manager applications that apparently take console-style queries and handle them, but initial browsing through their code, I'm not sure how they handle the translation. I absolutely love working with mongo in the console, but I'm rapidly starting to loathe the thought of converting every query into the format the native writer wants...

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  • Retrieving and displaying a contact name from a contact id while using a SimpleCursorAdapter

    - by Henrique
    I am storing information on the phone's contacts using a sqlite database. The fields I am storing are: _id, contact_id, body where _id is the row's id, contact_id is the phone contact's id and body is just a simple text which is the actual information I am storing. I'm using a SimpleCursorAdapter to map the data to the view, like so: Cursor cursor = database.fetchInformation(); // fetch info from DB String[] from = new String[] { CONTACT_ID, BODY }; int[] to = new int[] { R.id.contact, R.id.body }; SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.row, cursor, from, to); getListView().setAdapter(adapter); What I would actually want is to get the contact name that is associated with this CONTACT_ID, and have that be shown in the view. I can't seem to find a simple solution. I've tried implementing my own SimpleCursorAdapter and rewriting setViewText(TextView, String) but it didn't work. Also, it just seems overly complicated for such a simple task. Any help? Thanks.

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  • Node & Redis: Crucial Design Issues in Production Mode

    - by Ali
    This question is a hybrid one, being both technical and system design related. I'm developing the backend of an application that will handle approx. 4K request per second. We are using Node.js being super fast and in terms of our database struction we are using MongoDB, with Redis being a layer between Node and MongoDB handling volatile operations. I'm quite stressed because we are expecting concurrent requests that we need to handle carefully and we are quite close to launch. However I do not believe I've applied the correct approach on redis. I have a class Student, and they constantly change stages(such as 'active', 'doing homework','in lesson' etc. Thus I created a Redis DB for each state. (1 for being 'active', 2 for being 'doing homework'). Above I have the structure of the 'active' students table; xa5p - JSON stringified object #1 pQrW - JSON stringified object #2 active_student_table - {{studentId:'xa5p'}, {studentId:'pQrW'}} Since there is no 'select all keys method' in Redis, I've been suggested to use a set such that when I run command 'smembers' I receive the keys and later on do 'get' for each id in order to find a specific user (lets say that age older than 15). I've been also suggested that in fact I used never use keys in production mode. My question is, no matter how 'conceptual' it is, what specific things I should avoid doing in Node & Redis in production stage?. Are they any issues related to my design? Students must be objects and I sure can list them in a list but I haven't done yet. Is it that crucial in production stage?

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  • Ruby on Rails Mongrel web server stuck when MySQL service is running

    - by Marcos Buarque
    Hi, I am a Ruby on Rails newbie and already have a problem. I have started the Mongrel web server and it works fine when MySQL service isn't running. But when MySQL is on, Mongrel stucks. It ceases from serving the pages. So far, I have tested the localhost:3000 URL. When MySQL is off, it serves the page. When I click "about application's environment", I get the messasge (of course) "Can't connect to MySQL server on 'localhost' (10061)". After starting the MySQL service and refreshing, I get no more answer and Mongrel does not serve the webpage. It gets stuck with no answer to the browser. Then I have to stop the webserver and restart it. I have installed mysql2 gem with the command gem install mysql2. I was able to create the _test and _development databases with the command line rake db:create. I have tested with MySQL root user and blank password and also tried with a superuser user I have created. No success. Here is the server log: ======================== Started GET "/rails/info/properties" for 127.0.0.1 at Fri Dec 24 17:41:25 -0200 2010 Mysql2::Error (Can't connect to MySQL server on 'localhost' (10061)): Rendered C:/Ruby187/lib/ruby/gems/1.8/gems/actionpack-3.0.3/lib/action_dispatch/middleware/templates/rescues/_trace.erb (1.0ms) Rendered C:/Ruby187/lib/ruby/gems/1.8/gems/actionpack-3.0.3/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (5.0ms) Rendered C:/Ruby187/lib/ruby/gems/1.8/gems/actionpack-3.0.3/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (35.0ms) ================= I am running on a Windows 7 environment with firewall down.

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  • how to retrieve informatin from deleted row

    - by JM
    How can I retrie infromation from delete rows. I delete some rows from table in dataset, then I use method GetChanges(DataRowState.Deleted) to get deleted rows. I try delete rows in original table on server side, but it finished with this errors. System.Data.DeletedRowInaccessibleException: Deleted row information cannot be accessed through the row. What is correct way? Here is my code, any advice? Thank you everybody Dataset ds = //get dataset from client side //get changes DataTable delRows = ds.Tables[0].GetChanges(DataRowState.Deleted); //try delete rows in table in DB if (delRows != null) { string connStr = WebConfigurationManager.ConnectionStrings["Employees"].ConnectionString; conn = new SqlConnection(connStr); conn.Open(); for (int i = 0; i < delRows.Rows.Count; i++) { string cmdText = string.Format("DELETE Tab1 WHERE Surname=@Surname"); cmd = new SqlCommand() { Connection = conn, CommandText = cmdText }; //here is problem, I need get surnames from rows which was deleted var sqlParam = new SqlParameter(@"Surname", SqlDbType.VarChar) { Value = delRows.Rows[i][1].ToString() }; cmd.Parameters.Add(sqlParam); cmd.CommandText = cmdText; cmd.Connection = conn; cmd.ExecuteNonQuery(); } }

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  • Syncing magento database froms development to production

    - by ringerce
    I use git for version control. I have a development, staging and production environment. When I finish in development I push to staging for review by the client. When approved, I push changes from staging to production. That works fine as long as there is no database changes. What happens if I install modules via Magento connect on local development and it makes database modifications. How would I push those changes up to the production server since the production server is always changing? Edit: I wrote two shell scripts. One that pulls the production database down to my development server, replaces base url with develpment url and updates my development db accordingly. It also leaves the production sql dump behind to be added to my git repo. I'm not really sure if it's beneficial to keep the raw dumps in source control but I'm going to try it out. The second scripts moves the development database up to staging and essentially performs the same operations as the first. Now when it comes time to move to production I pull the updated production repo into the production server and allow magento to do it's thing. I also started using SQLYog recently and it has a database comparison wizard which will give me the differences in my development and production databases and allow me to merge the changes in selectively. It always creates a migration script that I added to source control as well. If anything goes wrong I can run the comparison to see if anything was missed. Does this sounds like a decent workflow to you guys?

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  • How to scale a PHP application (servers, mysql, memcache)

    - by Stéphane Goetz
    Hi, I'm currently creating a website for a social project in switzerland. And before there is an overflow of user, I want to prepare the application to scale. I answered by myself many questions but some are left. I explain what I want to do. First at the beginnning, the Application will have only one server (short time) with DNS, PHP, Mysql, Data, and memcache. Second Then I will split them in two DNS, Mysql, memcache Data, PHP Third Here is the problem, I don't know how to do it exactly here to keep the application running well. I could do : Front : Load Balancer, memcache, DNS Web 1 : PHP, DATA Web 2 : PHP, DATA Mysql This would be the scheme, all PHP sessions are kept in the DB. BUT, how do I sync the data? do I run a Rsync to keep them up to date. do I put them on a separate disk (network disk) to be sure ? but in this case, how can I do in case of user uploads ? and if the website gets more success and we have to go on greater structures, would'nt it create some latency on updates ? or would it be a good thing to go directly to amazon's web services ? some infos I use codeigniter as Framework. I use linux as webserver (distribution not chosen now, but should be Debian) Thanks in advance for your answers.

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  • Setting Class-Level Variable to Use Between Event Handlers

    - by lush
    I'm having a hard time understanding why the following code doesn't work. I'm sure it's something remedial that I'm missing or not understanding. I currently have a page that asks for user input. If, based on the input and logged in user, I find data from this page already in the database, I need to update the existing records rather than creating new ones, so I set a class-level bool to true. The problem is, when MyNextButton is clicked, PreviouslySubmitted is still false. So, I'm not sure how to make the value of this variable persist. Any advice is appreciated, thanks. public partial class MyForm : System.Web.UI.Page { private bool previouslySubmitted; protected void Page_Load(object sender, EventArgs e) { MyButton.Click += (o, i) => { q = from a in db.TableA where (a.SomeField == SomeValue) select a; if(q.Any()) { PreviouslySubmitted = true; //populate the form's fields with values from database for user to revise } } MyNextButton.Click += (o, i) => { if(PreviouslySubmitted) { //update database } else { //insert into database } }

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