Search Results

Search found 30858 results on 1235 pages for 'database tuning'.

Page 689/1235 | < Previous Page | 685 686 687 688 689 690 691 692 693 694 695 696  | Next Page >

• Scalability 101: How can I design a scalable web application using PHP?

  - by Legend

  I am building a web-application and have a couple of quick questions. From what I learnt, one should not worry about scalability when initially building the app and should only start worrying when the traffic increases. However, this being my first web-application, I am not quite sure if I should take an approach where I design things in an ad-hoc manner and later "fix" them. I have been reading stories about how people start off with an app that gets millions of users in a week or two. Not that I will face the same situation but I can't help but wonder, how do these people do it? Currently, I bought a shared hosting account on Lunarpages and that got me started in building and testing the application. However, I am interested in learning how to build the same application in a scalable-manner using the cloud, for instance, Amazon's EC2. From my understanding, I can see a couple of components: There is a load balancer that first receives requests and then decides where to route each request This request is then handled by a server replica that then processes the request and updates (if required) the database and sends back the response to the client If a similar request comes in, then a caching mechanism like memcached kicks into picture and returns objects from the cache A blackbox that handles database replication Specifically, I am trying to do the following: Setting up a load balancer (my homework revealed that HAProxy is one such load balancer) Setting up replication so that databases can be synchronized Using memcached Configuring Apache to work with multiple web servers Partitioning application to use Amazon EC2 and Amazon S3 (my application is something that will need great deal of storage) Finally, how can I avoid burning myself when using Amazon services? Because this is just a learning phase, I can probably do with 2-3 servers with a simple load balancer and replication but until I want to avoid paying loads of money accidentally. I am able to find resources on individual topics but am unable to find something that starts off from the big picture. Can someone please help me get started?

  Read the article

• SQL Server 2008 - Full Text Query

  - by user208662

  Hello, I have two tables in a SQL Server 2008 database in my company. The first table represents the products that my company sells. The second table contains the product manufacturer’s details. These tables are defined as follows: Product ------- ID Name ManufacturerID Description Manufacturer ------------ ID Name As you can imagine, I want to make this as easy as possible for our customers to query this data. However, I’m having problems writing a forgiving, yet powerful search query. For instance, I’m anticipating people to search based on phonetical spellings. Because of this, the data may not match the exact data in my database. In addition, I think some individuals will search by manufacturer’s name first, but I want the matching product names to appear first. Based on these requirements, I’m currently working on the following query: select p.Name as 'ProductName', m.Name as 'Manufacturer', r.Rank as 'Rank' from Product p inner join Manufacturer m on p.ManufacturerID=m.ID inner join CONTAINSTABLE(Product, Name, @searchQuery) as r Oddly, this query is throwing an error. However, I have no idea why. Squiggles appear to the right of the last parenthesis in management studio. The tool tip says "An expression of non-boolean type specified in a context where a condition is expected". I understand what this statement means. However, I guess I do not know how COntainsTable works. What am I doing wrong? Thank you

  Read the article

• SQL Server 2008 Stored Proc suddenly returns -1

  - by aaginor

  I use the following stored procedure from my SQL Server 2008 database to return a value to my C#-Program ALTER PROCEDURE [dbo].[getArticleBelongsToCatsCount] @id int AS BEGIN SET NOCOUNT ON; DECLARE @result int; set @result = (SELECT COUNT(*) FROM art_in_cat WHERE child_id = @id); return @result; END I use a SQLCommand-Object to call this Stored Procedure public int ExecuteNonQuery() { try { return _command.ExecuteNonQuery(); } catch (Exception e) { Logger.instance.ErrorRoutine(e, "Text: " + _command.CommandText); return -1; } } Till recently, everything works fine. All of a sudden, the stored procedure returned -1. At first, I suspected, that the ExecuteNonQuery-Command would have caused and Exception, but when stepping through the function, it shows that no Exception is thrown and the return value comes directly from return _command.ExecuteNonQuery(); I checked following parameters and they were as expected: - Connection object was set to the correct database with correct access values - the parameter for the SP was there and contained the right type, direction and value Then I checked the SP via SQLManager, I used the same value for the parameter like the one for which my C# brings -1 as result (btw. I checked some more parameter values in my C' program and they ALL returned -1) but in the manager, the SP returns the correct value. It looks like the call from my C# prog is somehow bugged, but as I don't get any error (it's just the -1 from the SP), I have no idea, where to look for a solution.

  Read the article

• Performing centralized authorization for multiple applications

  - by Vaibhav

  Here's a question that I have been wrestling with for a while. We have a situation wherein we have a number of applications that we have created. These have grown organically over a period of time. All of these applications have permissions code built into them that controls access to various parts of the application depending on whether the currently logged in user has the necessary permissions or not. Alongside these applications is a utility application which allows an administrator to map users to permissions for all applications - the way it works is that every application has code which reads this external database of the said utility application to check if the currently logged in user has the necessary permission or not. Now, the question is this. Should the user-permissions mapping information reside in and be owned by the applications themselves, or is it okay to have this information reside within an external entity/DB (as in this case the utility application's database). Part of me thinks that application permissions are very specific to the application context itself, so shouldn't be separated from the application itself. But I am not sure. Any comments?

  Read the article

• .htacces Rewrite Rule to Keep .php File Extensions

  - by user2672112

  I'm upgrading my static website that had .php extensions on the content pages. I've created my own simple cms which will start retrieving data from mysql database from now on, keeping the url structure same as the old once. The cms has get function to retrieve url structure from the database. Overall it started working fine with .html when i tested. But when i change the .html extension to .php in my .htaccess code the content pages starts reflecting "Internal Server Error. The server encountered an internal error or misconfiguration and was unable to complete your request." Here is my .htaccess code which i've used: RewriteBase / Options +FollowSymLinks RewriteEngine On RewriteRule ^([^?]*).php$ content.php?pid=$1 Perhaps there is a conflict, here is the code with .html extension that actually works fine. RewriteBase / Options +FollowSymLinks RewriteEngine On RewriteRule ^([^?]*).html$ content.php?pid=$1 So basically, content pages with .html are working & .php are not working. But i need my content pages to be with .php Please help. Thanks in advance... :)

  Read the article

• NHibernate / multiple sessions and nested objects

  - by bernhardrusch

  We are using NHibernate in a rich client application. It is a pretty open application (the user searches for a dataset or creates a new one, changes the data and saves the data set. We leave the session open, because sometimes we have to lazy load some properties of the object (nested object structure). This means one big problem if we leave the session open, the db (MySQL) closes the connection and we are not able to find this out and it throws an exception (socket communication error) when accessing the database (we are thinking about testing the db connection before accessing the object - but this is not really optimal neither, the other option would be to set back the timeout of the db connection , but this just doesn't seem to well). So - is it possible to reconnect the session to a new database connection ? Another problem is it possible to get an object from one session and then re-attach it to another session ? (I often hear that session.lock should work for this - but this doesn't work so well in our application - so I ended up getting a "fresh" object from the session and copy the data over manually - which is a little bit cumbersome) Any ideas for this ?

  Read the article

• Update PageTitle on Timer.Tick

  - by sohum

  I've got a page with a Timer that is being used as a trigger on an UpdatePanel. The page also contains a TabContainer and several TabPanels. Look at this question for more information. Basically, I've got an UpdatePanel as the element in each TabPanel's ContentTemplate, and the UpdatePanel is triggered by the Timer. My page displays data by reading a database on each tick. I've got the following code running on each Timer.Tick in my codebehind: protected void timeRefresher_Tick(object sender, EventArgs e) { UpdateLivePageTitle(); } The UpdateLivePageTitle() function reads the new information from the database and sets Page.Title accordingly. However, this information is of course not sent to the browser because there is no full page postback--only an async postback to the update panels. As a result, my page title is not being updated until the whole page is being posted back, which destroys the purpose of using UpdatePanels in the first place. I figure there would be a way to do this by using the document.title JS element and call that from within UpdateLivePageTitle(). But as of now, I haven't been able to figure out how to do this. I tried using the following in my UpdateLivePageTitle() function: string updatePageTitleScript = String.Format("document.title = '{0}'", newPageTitle); ToolkitScriptManager.RegisterStartupScript(this.Page, this.Page.GetType(), "UpdatePageTitle", updatePageTitleScript, true); But the result of this was that my TabContainer stopped rendering. I'm also not sure that would work with the async partial page postbacks, either. Any ideas? Thanks!

  Read the article

• @dynamic property needs setter with multiple behaviors

  - by ambertch

  I have a class that contains multiple user objects and as such has an array of them as an instance variable: NSMutableArray *users; The tricky part is setting it. I am deserializing these objects from a server via Objective Resource, and for backend reasons users can only be returned as a long string of UIDs - what I have locally is a separate dictionary of users keyed to UIDs. Given the string uidString of comma separated UIDs I override the default setter and populate the actual user objects: @dynamic users; - (void)setUsers:(id)uidString { users = [NSMutableArray arrayWithArray: [[User allUsersDictionary] objectsForKeys:[(NSString*)uidString componentsSeparatedByString:@","]]]; } The problem is this: I now serialize these to database using SQLitePO, which stores these as the array of user objects, not the original string. So when I retrieve it from database the setter mistakenly treats this array of user objects as a string! Where I actually want to adjust the setter's behavior when it gets this object from DB vs. over the network. I can't just make the getter serialize back into a string without tearing up large code that reference this array of user objects, and I tried to detect in the setter whether I have a string or an array coming in: if ([uidString respondsToSelector:@selector(addObject)]) { // Already an array, so don't do anything - just assign users = uidString but no success... so I'm kind of stuck - any suggestions? Thanks in advance!

  Read the article

• C# Interface Method calls from a controller

  - by ArjaaAine

  I was just working on some application architecture and this may sound like a stupid question but please explain to me how the following works: Interface: public interface IMatterDAL { IEnumerable<Matter> GetMattersByCode(string input); IEnumerable<Matter> GetMattersBySearch(string input); } Class: public class MatterDAL : IMatterDAL { private readonly Database _db; public MatterDAL(Database db) { _db = db; LoadAll(); //Private Method } public virtual IEnumerable<Matter> GetMattersBySearch(string input) { //CODE return result; } public virtual IEnumerable<Matter> GetMattersByCode(string input) { //CODE return results; } Controller: public class MatterController : ApiController { private readonly IMatterDAL _publishedData; public MatterController(IMatterDAL publishedData) { _publishedData = publishedData; } [ValidateInput(false)] public JsonResult SearchByCode(string id) { var searchText = id; //better name for this var results = _publishedData.GetMattersBySearch(searchText).Select( matter => new { MatterCode = matter.Code, MatterName = matter.Name, matter.ClientCode, matter.ClientName }); return Json(results); } This works, when I call my controller method from jquery and step into it, the call to the _publishedData method, goes into the class MatterDAL. I want to know how does my controller know to go to the MatterDAL implementation of the Interface IMatterDAL. What if I have another class called MatterDAL2 which is based on the interface. How will my controller know then to call the right method? I am sorry if this is a stupid question, this is baffling me.

  Read the article

• Error monitoring/handling on webservers

  - by Industrial

  Hi everybody, We have a web server that we're about to launch a number of applications onto. They will all share database and memcached servers, but each application has it's own mySQL database and all memcached keys per application, is prefixed. Possible scenario: If a memcached server in our cluster goes boom, we want someone (operative system admin) to be automatically contacted by email/iphone push notification or in any other appropriate way. If we we're about to install 150 identical applications for our customers on our servers, and a memcached server dies - all 150 applications will individually find this out and contact our system admin, which most certainly is going to think about getting a new job where he or she isn't about to be woken up by getting 150 messages sent 4:15 in the morning. Possible solution: One idea is to set up an external server for error handling that gets a $_POST or cURL request sent, and handles storage of the error message depending on the seriousness of the actual error message. It would of course check upon receiving the error call, that if the same memcached server have already been reported as offline, there would be no need to spam the system admin with additional reminders... The questions: What's a good approach on how to handle errors? How does the big guys in the industry handle this? Thanks!

  Read the article

• ExecuteNonQuery: Connection property has not been initialized

  - by 20151012

  I get an error in my code: The error point at dbcom.ExecuteNonQuery();. Code(connection) public admin_addemp() { InitializeComponent(); con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\EMPS.accdb;Persist Security Info=True"); con.Open(); ds.Tables.Add(dt); ds.Tables.Add(dt2); } Code (Save button) private void save_btn_Click(object sender, EventArgs e) { OleDbCommand check = new OleDbCommand(); check.Connection = con; check.CommandText = "SELECT COUNT(*) FROM employeeDB WHERE ([EmployeeName]=?)"; check.Parameters.AddWithValue("@EmployeeName", tb_name.Text); if (Convert.ToInt32(check.ExecuteScalar()) == 0) { dbcom2 = new OleDbCommand("SELECT EmployeeID FROM employeeDB WHERE EmployeeID='" + tb_id.Text + "'", con); OleDbParameter param = new OleDbParameter(); param.ParameterName = tb_id.Text; dbcom.Parameters.Add(param); OleDbDataReader read = dbcom2.ExecuteReader(); if (read.HasRows) { MessageBox.Show("The Employee ID '" + tb_id.Text + "' already exist. Please choose another Employee ID."); read.Dispose(); read.Close(); } else { string q = "INSERT INTO employeeDB (EmployeeID, EmployeeName, IC, Address, State, " + " Postcode, DateHired, Phone, ManagerName) VALUES ('" + tb_id.Text + "', " + " '" + tb_name.Text + "', '" + tb_ic.Text + "', '" + tb_add1.Text + "', '" + cb_state.Text + "', " + " '" + tb_postcode.Text + "', '" + dateTimePicker1.Value + "', '" + tb_hp.Text + "', '" + cb_manager.Text + "')"; dbcom = new OleDbCommand(q, con); dbcom.ExecuteNonQuery(); MessageBox.Show("New Employee '" + tb_name.Text + "'- Successfuly Added."); } } else { MessageBox.Show("Employee name '" + tb_name.Text + "' already added into the database"); } ds.Dispose(); } I'm using Microsoft Access 2010 as my database and this is stand alone system. Please help me.

  Read the article

• How To Correctly Specify A Default Value For A String Field In A PHP/MySQL Prepared Statement

  - by Joshua

  I'm trying to debug some auto-generated code, but I am a mySQL noob. Everything goes fine ultil the "prepare" line below, and then for some reason $mysqli_stmt is false, yielding the stated error. Could it have something to do with the SQL_MODE = 'ANSI'? The failure seems to have something to do with the string 'xxx' below, but it still happens no matter what I change it to. This value is meant to be a default value for the TickerDigest field, but strangely if I change 'xxx' to 'c_u_TickerDigest', then it suddenly works, but the TickerDigest field is inserted as 'null' when I look in the database. $mysqli = mysqli_init(); $mysqli->options(MYSQLI_INIT_COMMAND, "SET SQL_MODE = 'ANSI'"); $mysqli->real_connect(SR_Host,SR_Username,SR_Password,SR_Database) or die('Unable to connect to Database'); $sql_stmt = 'INSERT INTO "t_sr_u_Product"("c_u_Name", "c_u_Code", "c_u_TickerDigest") VALUES (?, ?, "xxx")'; $mysqli_stmt = $mysqli->prepare($sql_stmt); Fatal error: Uncaught exception 'Exception' with message 'INSERT INTO "t_sr_u_Product"("c_u_Name", "c_u_Code", "c_u_TickerDigest") VALUES (?, ?, "xxx"): prepare statement failed: Unknown column 'xxx' in 'field list'' in P:\StarRise\SandBox\GateKeeper\Rise\srIProduct.php on line 18 I'm hopeful what's going wrong is fairly simple, since I'm almost completely ignorant about SQL.

  Read the article

• Need help/suggestions for creating fantasy sports scoring databases and queries

  - by MGumbel

  I'm trying to create a website for my friends and I to keep track of fantasy sports scoring. So far, I've been doing the calculations and storage in Excel, which is very tedious. I'm trying to make it more simplified and automated through a SQL database that I can then wrap a web app around to enter daily stat updates. It's premised on our participation in another commercial site where we trade virtual shares of athletes, and thus acquire an "ownership percentage" in each athlete. For instance, if there are 100 shares of AROD, and I own 10 shares, then I own 10%. It then applies this to traditional baseball rotisserie scoring. So, for instance, if AROD has 1 HR today, then his adjusted HR stat would be 1.10. If he also has 2 RBI's, then his adjusted RBI stat today would be 2.20, based on (2 x 1.10)(1 to normalize the stat, and the .10 to represent the ownership percentage). All the stats for my team would then be summed each day and added to my stat history to come to an aggregated total. After that, points are allocated based on the ranking of each participant in each category at the end of the day. E.g. if there are 10 participants, and I have the highest total aggregate number of Adjusted HR's, then I get 10 pts. The points are then summed across the different stat categories to come up with a total point ranking for that day. An added difficulty is that ownership %'s can change on a daily basis. So far, in playing around with different schema, I don't know that having a separate table for each athlete's stats and each player's ownership %'s is the wisest choice. It seems to me that simply having two tables, one that contains the daily stat information for each athlete, and another that shows the ownership % of each player. My friend suggested using a start and end date for each ownership % to represent the potential daily changes in this category. I'm admittedly new to database development, so any suggestions on query code would be appreciated.

  Read the article

• MD5CryptoServiceProvider ComputeHash Issues between VS 2003 and VS 2008

  - by owensoroke

  I have a database application that generates a MD5 hash and compares the hash value to a value in our DB (SQL 2K). The original application was written in Visual Studio 2003 and a deployed version has been working for years. Recently, some new machines on the .NET framework 3.5 have been having unrelated issues with our runtime. This has forced us to port our code path from Visual Studio 2003 to Visual Studio 2008. Since that time the hash produced by the code is different than the values in the database. The original call to the function posted in code is: RemoveInvalidPasswordCharactersFromHashedPassword(Text_Scrub(GenerateMD5Hash(strPSW))) I am looking for expert guidance as to whether or not the MD5 methods have changed since VS 2K3 (causing this point of failure), or where other possible problems may be originating from. I realize this may not be the best method to hash, but utimately any changes to the MD5 code would force us to change some 300 values in our DB table and would cost us a lot of time. In addition, I am trying to avoid having to redeploy all of the functioning versions of this application. I am more than happy to post other code including the RemoveInvalidPasswordCharactersFromHashedPassword function, or our Text_Scrub if it is necessary to recieve appropriate feedback. Thank you in advance for your input. Public Function GenerateMD5Hash(ByVal strInput As String) As String Dim md5Provider As MD5 ' generate bytes for the input string Dim inputData() As Byte = ASCIIEncoding.ASCII.GetBytes(strInput) ' compute MD5 hash md5Provider = New MD5CryptoServiceProvider Dim hashResult() As Byte = md5Provider.ComputeHash(inputData) Return ASCIIEncoding.ASCII.GetString(hashResult) End Function

  Read the article

• mysql_affected_rows() returns 0 for UPDATE statement even when an update actually happens

  - by Alex Moore

  I am trying to get the number of rows affected in a simple mysql update query. However, when I run this code below, PHP's mysql_affected_rows() always equals 0. No matter if foo=1 already (in which case the function should correctly return 0, since no rows were changed), or if foo currently equals some other integer (in which case the function should return 1). $updateQuery = "UPDATE myTable SET foo=1 WHERE bar=2"; mysql_query($updateQuery); if (mysql_affected_rows() > 0) { echo "affected!"; } else { echo "not affected"; // always prints not affected } The UPDATE statement itself works. The INT gets changed in my database. I have also double-checked that the database connection isn't being closed beforehand or anything funky. Keep in mind, mysql_affected_rows doesn't necessarily require you to pass a connection link identifier, though I've tried that too. Details on the function: mysql_affected_rows Any ideas? SOLUTION The part I didn't mention turned out to be the cause of my woes here. This PHP file was being called ten times consecutively in an AJAX call, though I was only looking at the value returned on the last call, ie. a big fat 0. My apologies!

  Read the article

• How to change Hibernate´s auto persistance strategy

  - by Kristofer Borgstrom

  I just noted that my hibernate entities are automatically persisted to the database (or at least to cache) before I call any save() or update() method. To me this is a pretty strange default behavior but ok, as long as I can disable it, it´s fine. The problem I have is I want to update my entity´s state (from 1 to 2) only if the entity in the database still has the state it had when I retrieved [1] (this is to eliminate concurrency issues when another server is updating this same object). For this reason I have created a custom NamedQuery that will only update the entity if state is 1. So here is some pseudo-code: //Get the entity Entity item = dao.getEntity(); item.getState(); //==1 //Update the entity item.setState(2); //Here is the problem, this effectively changes the state of my entity braking my query that verifies that state is still == 1. dao.customUpdate(item); //Returns 0 rows changes since state != 1. So, how do I make sure the setters don´t change the state in cache/db? Thanks, Kristofer

  Read the article

• JPA + EJB + JSF: how can design complicated query

  - by Harry Pham

  I am using netbean 6.8 btw. Let say that I have 4 different tables: Company, Facility, Project, and Document. So the relationship is this. A company can have multiple facilities. A facility can have multiple projects, and a project can have multiple documents. Company: +companyNum: PK +facilityNum: FK Facility: +facilityNum: PK +projectNum: FK Project: +projectNum: PK +drawingNum: FK So when I create Entity Class From Database in netbean 6.8, I have 4 entity classes that named after the above 4 tables. So if I want to see all the Document in the database, then it is easy. In my SessionBean, I would do this: @PersistenceContext private EntityManager em; List<Document> documents = em.createNamedQuery("Document.findAll").getResultList(); However, that is not all what I need. Let say that I want to know all the Document from a particular Company, or all the Document from a particular Project from a particular Facility from a particular Company. I am very new to JPA + EJB + JSF as a whole. Please help me out.

  Read the article

• nservicebus deleting subscription record after inserting it?

  - by Justin Holbrook

  I have been playing with nservicebus for a few weeks now and since everything was going well on my local machine I decided to try to set up a test environment and work on deployment. I am using the generic host that comes with nservicebus and was using the nservicebus.Integration profile when running locally, but would like to use Nservicebus.Production in the test environment. I set up a sql server 2008 database, made changes to my app.config and everything seemed to work fine. But after a few attempts, I noticed messages were not being picked up by my subscriber. I checked the subscription table and it was empty. Upon examination of the logs I noticed the following: 2010-05-06 15:07:57,416 [1] DEBUG NHibernate.Persister.Entity.AbstractEntityPers ister [(null)] <(null) - Insert 0: INSERT INTO [Subscription] (SubscriberEndpo int, MessageType) VALUES (?, ?) 2010-05-06 15:07:57,416 [1] DEBUG NHibernate.Persister.Entity.AbstractEntityPers ister [(null)] <(null) - Update 0: 2010-05-06 15:07:57,416 [1] DEBUG NHibernate.Persister.Entity.AbstractEntityPers ister [(null)] <(null) - Delete 0: DELETE FROM [Subscription] WHERE Subscriber Endpoint = ? AND MessageType = ? Why would it insert then delete my subscription right afterwards? To try to rule out a nhibernate dialect issue I tried switching my subscription storage to an oracle 10g database. It behaved exactly the same, it worked the first 2 times, then I started seeing my subscriptions being deleted right after they were inserted. Any ideas what is causing this behavior?

  Read the article

• Wrong label for a nodereference in Drupal content-type

  - by MPD

  We have a content-type built using CCK. One of the fields is a node reference. The node picker is using a view to build the options. A few days ago, everything was working well. Today, it looks like all node reference fields using views to populate the selection options are displaying the wrong label. Every single label in the option is ``A'', but the actual node number is correct. The form actually works, just the labels are incorrect. We have tried just about every combination of edit/save, disable/enable, reboot, clear cache, clone the view, rebuild the view, new view, etc, but we still have a big list of As. If we create a brand new content type with a brand new node reference field, we get the problem. Through some backup/restore exercises, we have determined that the problem is actually in the database and not in the code. We can restore our last good backup, but we will lose a decent amount of work we have put into other parts of the database. We enabled mysql query logging, and the view is actually being called properly, but we cannot track down where the problem is creeping in after that (unraveling the CCK / Views / Drupal plumbing is a challenge). The install was build with latest stable versions as of April. The problems referred to in http://drupal.org/node/624422 is similar, but our code versions include the patches mentioned. Any ideas would be appreciated. Thanks.

  Read the article

• Security strategies for storing password on disk

  - by Mike

  I am building a suite of batch jobs that require regular access to a database, running on a Solaris 10 machine. Because of (unchangable) design constraints, we are required use a certain program to connect to it. Said interface requires us to pass a plain-text password over a command line to connect to the database. This is a terrible security practice, but we are stuck with it. I am trying to make sure things are properly secured on our end. Since the processing is automated (ie, we can't prompt for a password), and I can't store anything outside the disk, I need a strategy for storing our password securely. Here are some basic rules The system has multiple users. We can assume that our permissions are properly enforced (ie, if a file with a is chmod'd to 600, it won't be publically readable) I don't mind anyone with superuser access looking at our stored password Here is what i've got so far Store password in password.txt $chmod 600 password.txt Process reads from password.txt when it's needed Buffer overwritten with zeros when it's no longer needed Although I'm sure there is a better way.

  Read the article

• How do you bind SQL Data to a .NET DataGridView?

  - by Jordan S

  I am trying to bind a table in an SQL database to a DataGridView Control. I would like to make it so that when the user enters a new line of data in the DataGridView that a record is automatically added to the database. Is there a way to do this using LINQ to SQL? I have tried using the code below but after I add a new entry I dont think the data gets added to the DB. Please Help! BOMClassesDataContext DB = new BOMClassesDataContext(); var mfrs = from m in DB.Manufacturers select m; BindingSource bs = new BindingSource(); bs.DataSource = mfrs; dataGridView1.DataSource = bs; I tried adding DB.SubmitChanges() to the CellValueChanged eventhandler and that partially works. If I click the bottom empty row it automatically fills in the ID (identity) column of the table with a "0" instead of the next unused value. If I change that value manually to the next available then it adds the new record fine but if I leave it at 0 it does nothing. How can i fix this?

  Read the article

• How does Access 2007's moveNext/moveFirst/, etc., feature work?

  - by Chris M

  I'm not an Access expert, but am an SQL expert. I inherited an Access front-end referencing a SQL 2005 database that worked OK for about 5000 records, but is failing miserably for 800k records... Behind the scenes in the SQL profiler & activity manager I see some kind of Access query like: SELECT "MS1"."id" FROM "dbo"."customer" "MS1" ORDER BY "MS1"."id" The MS prefix doesn't appear in any Access code I can see. I'm suspicious of the built-in Access navigation code: DoCmd.GoToRecord , , acNext The GoToRecord has AcRecord constant, which includes things like acFirst, acLast, acNext, acPrevious and acGoTo. What does it mean in a database context to move to the "next" record? This particular table uses an identity column as the PK, so is it internally grabbing all the IDs and then moving to the one that is the next highest??? If so, how would it work if a table was comprised of three different fields for the PK? Or am I on the wrong track, and something else in Access is calling that statement? Unfortunately I see a ton of prepared statements in the profiler. THanks!

  Read the article

• Entity framework self referencing loop detected

  - by Lyd0n

  I have a strange error. I'm experimenting with a .NET 4.5 Web API, Entity Framework and MS SQL Server. I've already created the database and set up the correct primary and foreign keys and relationships. I've created a .edmx model and imported two tables: Employee and Department. A department can have many employees and this relationship exists. I created a new controller called EmployeeController using the scaffolding options to create an API controller with read/write actions using Entity Framework. In the wizard, selected Employee as the model and the correct entity for the data context. The method that is created looks like this: // GET api/Employee public IEnumerable<Employee> GetEmployees() { var employees = db.Employees.Include(e => e.Department); return employees.AsEnumerable(); } When I call my API via /api/Employee, I get this error: ...The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; ...System.InvalidOperationException","StackTrace":null,"InnerException":{"Message":"An error has occurred.","ExceptionMessage":"Self referencing loop detected with type 'System.Data.Entity.DynamicProxies.Employee_5D80AD978BC68A1D8BD675852F94E8B550F4CB150ADB8649E8998B7F95422552'. Path '[0].Department.Employees'.","ExceptionType":"Newtonsoft.Json.JsonSerializationException","StackTrace":" ... Why is it self referencing [0].Department.Employees? That doesn't make a whole lot of sense. I would expect this to happen if I had circular referencing in my database but this is a very simple example. What could be going wrong?

  Read the article

• TextBox change is not saved to DataTable

  - by SeaDrive

  I'm having trouble with a simple table edit in a Winform application. I must have missed a step. I have a DataSet containing a DataTable connected to a database with a SqlDataAdapter. There is a SqlCommandBuilder on the SqlDataAdapter. On the form, there are TextBoxes which are bound to the DataTable. The binding was done in the Designer and it machine-produced statements like this: this.tbLast.DataBindings.Add(new System.Windows.Forms.Binding("Text", this.belkData, "belk_mem.last", true)); When I fill the row in the DataTable, the values from the database appear in the textboxes, but when I change contents of the TextBox, the changes are apparently not being going to the DataTable. When I try to save change both of the following return null: DataTable dtChanges = dtMem.GetChanges(); DataSet dsChanges = belkData.GetChanges(); What did I forget? Edit - response to mrlucmorin: The save is under a button. Code is: BindingContext[belkData, "belk_mem"].EndCurrentEdit(); try { DataSet dsChanges = belkData.GetChanges(); if (dsChanges != null) { int nRows = sdaMem.Update(dsChanges); MessageBox.Show("Row(s) Updated: " + nRows.ToString()); belkData.AcceptChanges(); } else { MessageBox.Show("Nothing to save.", "No changes"); } } catch (Exception ex) { MessageBox.Show("Error: " + ex.Message); } I've tried putting in these statements without any change in behavior: dtMem.AcceptChanges(); belkData.AcceptChanges();

  Read the article

• What are the Limitations for Connecting to an Access Query in Excel

  - by thornomad

  I have an Access 2007 database that has a number of tables, some are fairly large (100,000+ records); I have created a union query to pull some of the same types of data from multiple tables into one large query for pivot table manipulation and reporting. For example: SELECT Language FROM Table1 UNION ALL SELECT Language FROM Table2 UNION ALL SELECT Language FROM Table3; This works. I found, quickly, however, that a union query will not show up when connecting to the datasource from Excel 2007. So, I created a second query to reference the union query. Like so: SELECT * FROM [The Above Union Query]; This query works and it, initially, was accessible from Excel. Time passed, I've added more data. Suddenly, when I connect to my Access database from Excel my query referencing the union has disappeared. MS Access shows no signs of an issue (data displays in Access) and my other non-union queries are showing up in Excel 2007 ... but not the one that references the union. What could be going on? Why did it disappear? I noticed if I switch some of the referenced tables in the union query to a smaller table (with less rows) all of sudden the query appears in Excel again. At least, I think that's what the difference is. I really can't put my finger on why some of the union queries won't show up and some will. Am stumped and need some guidance. Thanks.

  Read the article

< Previous Page | 685 686 687 688 689 690 691 692 693 694 695 696  | Next Page >