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• Why is PHP not allowing comparison?

  - by dcp3450

  I'm using PHP to read if an entry in my table on the database is set to "yes" or "no" and auto check the radio button that corresponds: <?php include 'file.php'; $query = "SELECT * FROM TABLE"; $runquery = odbc_exec($connect,$query); $status= odbc_result($runquery,"status"); odbc_close($file); ?> <form> <div class="formContainer"> <fieldset> <legend>Campus Alert<span class="tooltip">Turn campus alert on and off.</span></legend> <?php echo $status; ?> Yes <input type="radio" name="alertStatus" id="alertStatus" value="yes" <?php if($status== "yes") echo "checked";?>> No <input type="radio" name="alertStatus" id="alertStatus" value="no" <?php if($status== "no") echo "checked";?>> </fieldset> </div> the is for debugging so I can make sure what the database says and the form's reaction is correct. It prints "yes" (no quotes). However, the if statement will not respond. Any idea why it's doing this?

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• Fluent config not generating mapping files

  - by rboarman

  Hello, I am trying to get Fluent nHibernate to generate mappings so I can take a look at the files and the sql. My code is based on this post and on what I can glean from the documentation. http://stackoverflow.com/questions/1375146/fluent-mapping-entities-and-classmaps-in-different-assemblies I am using the latest code from git. Here’s my config code: Configuration cfg = new Configuration(); var ft = Fluently.Configure(cfg); //DbConnection by fluent ft.Database ( MsSqlConfiguration .MsSql2008 .ConnectionString("……") .ShowSql() .UseReflectionOptimizer() ); //get mapping files. ft.Mappings(m => { //set up the mapping locations m.FluentMappings.AddFromAssemblyOf<Entity>() .ExportTo(@"C:\temp"); m.Apply(cfg); }); I also tried: var sessionFactory = Fluently.Configure() .Database(MsSqlConfiguration .MsSql2008 .ShowSql() .ConnectionString(“……")) .Mappings(p => p.FluentMappings .AddFromAssemblyOf<Entity>() .ExportTo(@"c:\temp\")) .BuildSessionFactory(); I have verified that the connection string is correct. The issue is that no mapping files show up in the ExportTo folder and no sql code shows up in the output window or in the log file. No errors or exceptions are generated either. I have no idea where to go from here. Thank you in advance. Rick

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• stock management of assemblys and its sub parts

  - by The Disintegrator

  I have to track the stock of individual parts and kits (assembly) and can't find a satisfactory way of doing this. Sample bogus and hyper simplified database: Table prod: prodID 1 prodName Flux capacitor prodCost 900 prodPrice 1350 (900*1.5) prodStock 3 - prodID 2 prodName Mr Fusion prodCost 300 prodPrice 600 (300*2) prodStock 2 - prodID 3 prodName Time travel kit prodCost 1650 (1350+300) prodPrice 2145 (1650*1.3) prodStock 2 Table rels relID 1 relSrc 1 (Flux capacitor) relType 4 (is a subpart of) relDst 3 (Time travel kit) - relID 2 relSrc 2 (Mr Fusion) relType 4 (is a subpart of) relDst 3 (Time travel kit) prodPrice: it's calculated based on the cost but not in a linear way. In this example for costs of 500 or less, the markup is a 200%. For costs of 500-1000 the markup is 150%. For costs of 1000+ the markup is 130% That's why the time travel kit is much cheaper than the individual parts prodStock: here is my problem. I can sell kits or the individual parts, So the stock of the kits is virtual. The problem when I buy: Some providers sell me the Time Travel kit as a whole (with one barcode) and some sells me the individual parts (with a different barcode) So when I load the stock I don't know how to impute it. The problem when I sell: If I only sell kits, calculate the stock would be easy: "I have 3 Flux capacitors and 2 Mr Fusions, so I have 2 Time travel kits and a Flux Capacitor" But I can sell Kits or individual parts. I have to track the stock of the individual parts and the possible kits at the same time (and I have to compensate for the sell price) Probably this is really simple, but I can't see a simple solution. Resuming: I have to find a way of tracking the stock and the database/program is the one who has to do it (I cant ask the clerk to correct the stock) I'm using php+MySql. But this is more a logical problem than a programing one

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• Setting nested object to null when combobox has empty value

  - by Javi

  Hello, I have a Class which models a User and another which models his country. Something like this: public class User{ private Country country; //other attributes and getter/setters } public class Country{ private Integer id; private String name; //other attributes and getter/setters } I have a Spring form where I have a combobox so the user can select his country or can select the undefined option to indicate he doen't want to provide this information. So I have something like this: <form:select path="country"> <form:option value="">-Select one-</form:option> <form:options items="${countries}" itemLabel="name" itemValue="id"/> </form:select> In my controller I get the autopopulated object with the user information and I want to have country set to null when the "-Select one-" option has been selected. So I have set a initBinder with a custom editor like this: @InitBinder protected void initBinder(WebDataBinder binder) throws ServletException { binder.registerCustomEditor(Country.class, "country", new CustomCountryEditor()); } and my editor do something like this: public class CustomCountryEditor(){ @Override public String getAsText() { //I return the Id of the country } @Override public void setAsText(String str) { //I search in the database for a country with id = new Integer(str) //and set country to that value //or I set country to null in case str == null } } When I submit the form it works because when I have country set to null when I have selected "-Select one-" option or the instance of the country selected. The problem is that when I load the form I have a method like the following one to load the user information. @ModelAttribute("user") public User getUser(){ //loads user from database } The object I get from getUser() has country set to a specific country (not a null value), but in the combobox is not selected any option. I've debugged the application and the CustomCountryEditor works good when setting and getting the text, thoughgetAsText method is called for every item in the list "countries" not only for the "country" field. Any idea? Is there a better way to set null the country object when I select no country option in the combobox? Thanks

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• Detection of page refresh / F5 key in ASP.NET MVC 2

  - by Michael

  How would one go about detecting a page refresh / F5 key push on the controller handling the postback? I need to distinguish between the user pressing one of two buttons (e.g., Next, Previous) and when the F5 / page refresh occurs. My scenario is a single wizard page that has different content shown between each invocation of the user pressing the "Next" or "Previous" buttons. The error that I am running into is when the user refreshes the page / presses the F5 key, the browser re-sends the request back to the controller, which is handled as a post-back and the FormCollection type is used to look for the "submitButton" key and obtain its value (e.g., "Next," "Send"). This part was modeled after the post by Dylan Beattie at http://stackoverflow.com/questions/442704/how-do-you-handle-multiple-submit-buttons-in-asp-net-mvc-framework. Maybe I'm trying to bend MVC 2 to where it isn't meant to go but I'd like to stay with the current design in that the underlying database drives the content and order of what is shown. This allows us to add new content into the database without modifying the code the displays the content. Thanks, Michael

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• How to use Subsonic 2.0 ?

  - by programmerist

  i try to use subsonic 3.0 but i can not do that. i decided to use subsonic.2.0. So i try to make it i can not :( my Web Config : <?xml version="1.0" encoding="utf-8" ?> <configuration> <configSections> <section name="SubSonicService" type="SubSonic.SubSonicSection, SubSonic" requirePermission="false"/> </configSections> <connectionStrings> <add name="AdventureWorks" connectionString="Data Source=.;Database=eticaret; Integrated Security=true; User ID=sa; Password=123456;"/> </connectionStrings> <SubSonicService defaultProvider="eticaret"> <providers> <clear/> <add name="eticaret" type="SubSonic.SqlDataProvider, SubSonic" connectionStringName="eticaret" generatedNamespace="eticaretDAL"/> </providers> </SubSonicService> </configuration> also look this article: what is error? http://www.codeproject.com/KB/database/SubsonicDAL.aspx

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• Time to start returning IQueryable<T> instead of IList<T> to my Web UI / Web API Layer?

  - by JohnnyO

  I've got a multi-layer application that starts with the repository pattern for all data access and it returns IQueryable to the Services layer. The Services layer, which includes all of the business logic, returns IList to the Controllers (note: I'm using ASP.NET MVC for the UI layer). The benefit of returning IQueryable in the data access layer is that it allows my repositories to be extremely simple and the database queries to be deferred. However, I'm triggering the database queries in my services layer so that my unit tests is more reliable and I don't give flexibility to the Controllers to reshape my queries. However, I've recently encountered several situations where deferring the execution of queries down to the Controllers would have been significantly more performant because the Controllers had to do some projections on the data that was UI specific. Additionally, with the emergence of things like oData, I was starting to wonder if end points (e.g. web UI or web apis) should be working directly with IQueryable. What are your thoughts? Is it time to start returning IQueryable from the services layer to the UI layer? Or stick with IList? This thread here: http://stackoverflow.com/questions/718624/to-return-iqueryablet-or-not-return-iqueryablet seems to vouch for returning IList to the UI layers, but I was wondering if things are changing because of new emerging technologies and techniques.

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• How can I turn a column name into a result value in SQL Server?

  - by Brennan

  I have a table which has essentially boolean values in a legacy database. The column names are stored as string values in another table so I need to match the column names of one table to a string value in another table. I know there has to be a way to do this directly with SQL in SQL Server but it is beyond me. My initial thought was to use PIVOT but it is not enabled by default and enabling it would likely be a difficult process with pushing that change to the Production database. I would prefer to use what is enabled by default. I am considering using COALESCE to translate the boolean value to the string that value that I need. This will be a manual process. I think I will also use a table variable to insert the results of the first query into that variable and use those results to do the second query. I still have the problem that the columns are on a single row so I wish I could easily pivot the values to put the column names in the result set as strings. But if I could easily do that I could easily write the query with a sub-select. Any tips are welcome.

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• What are some techniques to monitor multiple instances of a piece of software?

  - by Geo Ego

  I have a piece of self-serve kiosk software that will be running at multiple sites. I'd like to monitor their status remotely. The kiosk application itself is pretty much finished. I am now in the process of creating a piece of software that will monitor all of the kiosks from a central location so that the customer can view particular details remotely (for instance, how many bills are in the acceptor's cash cartridge, what customer is currently logged in, etc.). Because I am in such an early stage of development, my options are quite open. I understand that I'm not giving very many qualifications, but I'd like to try to get a good variety of potential solutions. Some details: Kiosk software is a VB6 app running on Windows Embedded Monitoring software will be run on a modern desktop version of Windows (either XP, Vista, or 7) Database is SQL Server 2008 My initial idea was to develop a .NET app that would simply report the last database transaction for each kiosk at a set interval (say every second or so) but I'd really like for the kiosk software to report its status directly. I'm not exactly sure where to begin in terms of what modifications may need to be made to the kiosk software, and what the monitoring software will require. Links to articles on these topics would be most welcome.

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• InsertOnSubmit - NullReferenceException

  - by Jackie Chou

  I have 2 Model AccountEntity [Table(Name = "Account")] public class AccountEntity { [Column(IsPrimaryKey = true, IsDbGenerated = true, AutoSync = AutoSync.OnInsert)] public int id { get; set; } [Column(CanBeNull = false, Name = "email")] public string email { get; set; } [Column(CanBeNull = false, Name = "pwd")] public string pwd { get; set; } [Column(CanBeNull = false, Name = "row_guid")] public Guid guid { get; set; } private EntitySet<DetailsEntity> details_id { get; set; } [Association(Storage = "details_id", OtherKey = "id", ThisKey = "id")] public ICollection<DetailsEntity> detailsCollection { get; set; } } DetailsEntity [Table(Name = "Details")] public class DetailsEntity { public DetailsEntity(AccountEntity a) { this.Account = a; } [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "int")] public int id { get; set; } private EntityRef<AccountEntity> _account = new EntityRef<AccountEntity>(); [Association(IsForeignKey = true, Storage = "_account", ThisKey = "id")] public AccountEntity Account { get; set; } } Main using (Database db = new Database()) { AccountEntity a = new AccountEntity(); a.email = "hahaha"; a.pwd = "13212312"; a.guid = Guid.NewGuid(); db.Account.InsertOnSubmit(a); db.SubmitChanges(); } that has relationhip AccountEntity <- DetailsEntity (1-n) when i'm trying to insert a record exception throws NullReferenceException cause: by EntitySet null please help me make it insert

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• Mysql Powerdns issue when adding a new CName record

  - by Roland

  I'm trying to add a new CNAME record in PowerDNS to the mysql database, but my website does not want to show. When adding it in via Zone Admin it works, but as soon as I add the record as below it just does not want to work. Am I doing something wrong here. I checked if my record looks exactly the same in the DB as the record added with PowerDNS and it does. $type = 'CNAME'; //Adding the subdomain to the DNS database $sql = "insert into records " . "(domain_id, name,type,content,ttl,prio,change_date) values("; $sql .= $domain_id . ",'"; $sql .= trim($subdomain).".". trim($domain) . "','"; $sql .= trim($type) . "','"; $sql .= trim($domain) . "',"; $sql .= "3600,0,'".time()."')";

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• LINQ to SQL - Tracking New / Dirty Objects

  - by Joseph Sturtevant

  Is there a way to determine if a LINQ object has not yet been inserted in the database (new) or has been changed since the last update (dirty)? I plan on binding my UI to LINQ objects (using WPF) and need it to behave differently depending whether or not the object is already in the database. MyDataContext context = new MyDataContext(); MyObject obj; if (new Random().NextDouble() > .5) obj = new MyObject(); else obj = context.MyObjects.First(); // How can I distinguish these two cases? The only simple solution I can think of is to set the primary key of new records to a negative value (my PKs are an identity field and will therefore be set to a positive integer on INSERT). This will only work for detecting new records. It also requires identity PKs, and requires control of the code creating the new object. Is there a better way to do this? It seems like LINQ must be internally tracking the status of these objects so that it can know what to do on context.SubmitChanges(). Is there some way to access that "object status"? Clarification Apparently my initial question was confusing. I'm not looking for a way to insert or update records. I'm looking for a way, given any LINQ object, to determine if that object has not been inserted (new) or has been changed since its last update (dirty).

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• How to create a rails staging environment in engineyard?

  - by siulamvictor

  I have a production instance in engineyard up and running well. I would like to create a new staging instance for internal testing. I cloned the existing production instance, changed Framework Environment to staging. I can deploy all the code to staging instance from Github. Engineyard reported the server is fully configured and ready. I have subdomain-fu in my Rails app, as I have some subdomain handling in my app. I set the subdomain initializer like this.... SubdomainFu.tld_sizes = {:development => 1, :test => 0, :production => 1, :staging => 2} As the production instance is using the domain xxxxx.com, I would like my staging instance use the domain staging.xxxxx.com. But I got an error when open this domain. Seems the app use xxxxx.com as domain but not the staging.xxxxx.com. I checked the engineyard database.yml. It use xxxxx_production database, I supposed it should be xxxxx_staging. Seems the engineyard instance is not set to staging environment, but just clone all the setting from production server. Does anyone have experience with this and can show me the way on how to fix it? Thanks. :)

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• Is SQLDataReader slower than using the command line utility sqlcmd?

  - by Andrew

  I was recently advocating to a colleague that we replace some C# code that uses the sqlcmd command line utility with a SqlDataReader. The old code uses: System.Diagnostics.ProcessStartInfo procStartInfo = new System.Diagnostics.ProcessStartInfo("cmd", "/c " + sqlCmd); wher sqlCmd is something like "sqlcmd -S " + serverName + " -y 0 -h-1 -Q " + "\"" + "USE [" + database + "]" + ";+ txtQuery.Text +"\"";\ The results are then parsed using regular expressions. I argued that using a SQLDataReader woud be more in line with industry practices, easier to debug and maintain and probably faster. However, the SQLDataReader approach is at least the same speed and quite possibly slower. I believe I'm doing everything correctly with SQLDataReader. The code is: using (SqlConnection connection = new SqlConnection()) { try { SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder(connectionString); connection.ConnectionString = builder.ToString(); ; SqlCommand command = new SqlCommand(queryString, connection); connection.Open(); SqlDataReader reader = command.ExecuteReader(); // do stuff w/ reader reader.Close(); } catch (Exception ex) { outputMessage += (ex.Message); } } I've used System.Diagnostics.Stopwatch to time both approaches and the command line utility (called from C# code) does seem faster (20-40%?). The SqlDataReader has the neat feature that when the same code is called again, it's lightening fast, but for this application we don't anticipate that. I have already done some research on this problem. I note that the command line utility sqlcmd uses OLE DB technology to hit the database. Is that faster than ADO.NET? I'm really suprised, especially since the command line utility approach involves starting up a process. I really thought it would be slower. Any thoughts? Thanks, Dave

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• How to convert an InputStream to a DataHandler?

  - by pcorey

  I'm working on a java web application in which files will be stored in a database. Originally we retrieved files already in the DB by simply calling getBytes on our result set: byte[] bytes = resultSet.getBytes(1); ... This byte array was then converted into a DataHandler using the obvious constructor: dataHandler=new DataHandler(bytes,"application/octet-stream"); This worked great until we started trying to store and retrieve larger files. Dumping the entire file contents into a byte array and then building a DataHandler out of that simply requires too much memory. My immediate idea is to retrieve a stream of the data in the database with getBinaryStream and somehow convert that InputStream into a DataHandler in a memory-efficient way. Unfortunately it doesn't seem like there's a direct way to convert an InputStream into a DataHandler. Another idea I've been playing with is reading chunks of data from the InputStream and writing them to the OutputStream of the DataHandler. But... I can't find a way to create an "empty" DataHandler that returns a non-null OutputStream when I call getOutputStream... Has anyone done this? I'd appreciate any help you can give me or leads in the right direction.

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• PerformancePoint dashboard permissions problem in MOSS

  - by Nathan DeWitt

  I have a PerformancePoint dashboard running in MOSS 2007 portal. The dashboard consists of one SSRS 2005 report, running in SharePoint Integrated mode. NT Authority\Authenticated Users have read permissions to the report library containing the SSRS report, the dashboard, and the report library containing the dashboard. Users that attempt to access the dashboard receive the following error message: The permissions granted to user 'DOMAIN\firstname.lastname' are insufficient for performing this operation. (rsAccessDenied) Users that then click on the direct link to the report in MOSS will see the report with no problem. Subsequent visits to the dashboard show the report with no problem. The report is using a data source that is located one folder up from the report location. The report has been updated to point to the correct shared data source after deployment. Both the report and the data source have been published. The data source is using stored credentials, with a domain service account that has been set to Use as Windows credentials. This service account is serving other reports in other areas with no problem. Edit: Ok, I've gotten a lot more information on this problem. The request is never actually being made to the data source. The user comes in to the dashboard and requests a report for the first time using their kerberos token identifying themselves. The report looks in the Report Server database and finds that they are not listed in the users table and generates this rsAccessDenied error. Once they view the report directly their name is in this table and they never have the problem again. Unfortunately, removing the user from the Users table in the RS database doesn't actually cause this error to happen again. Everything I've read says that when you run a Report Server in MOSS integrated mode all your permissions are handled at the MOSS report library level, and all Auth users have permissions to the report library, as stated earlier. Any ideas?

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• Help with editing data in entity framework.

  - by Levelbit

  Title of this question is simple because there is no an easy explanation for what I'm trying to ask you. I hope you'll understand in the end :). I have to tables in my database: Company and Location (relationship:one to many) and corresponding entity sets. In my wpf application I have some datagrid which I want to fill with locations and to be able to edit every row in separate window as some form of details view (so I don't want to edit my data in datagrid). I did this by accessing Location entity from selected row and creating a new Location entity and then I copy properties from original entity to newly created. Something like cloning the object. After editing if I press OK changed data is copied to original object back, and if I press Cancel nothing happens. Of course, you probably thinking I could use NoTracking option and AttachAsModified method as was mentioned as solution in some earlier questions(see:http://stackoverflow.com/questions/803022/changing-entities-in-the-entityframework) by Alex James, but lets say I had some problems about that and I have my own reasons for doing this. Finally, because navigation property(Company) of my location entity is assigned to newly created location object(during cloning) from some reason in object context additional object as copy of object I want to edit from datagrid is created without my will(similar problem :http://blogs.msdn.com/alexj/archive/2009/12/02/tip-47-how-fix-up-can-make-it-hard-to-change-relationships.aspx). So, when I do ObjectContext.SaveChanges it inserts additional row of data into my database table Location, the same as the one i wanted to edit. I read about sth like this, but I don't quite understand why is that and how to block or override this. I hope I was clear as I could. Please, solutions or some other ideas.

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• Relay WCF Service

  - by Matt Ruwe

  This is more of an architectural and security question than anything else. I'm trying to determine if a suggested architecture is necessary. Let me explain my configuration. We have a standard DMZ established that essentially has two firewalls. One that's external facing and the other that connects to the internal LAN. The following describes where each application tier is currently running. Outside the firewall: Silverlight Application In the DMZ: WCF Service (Business Logic & Data Access Layer) Inside the LAN: Database I'm receiving input that the architecture is not correct. Specifically, it has been suggested that because "a web server is easily hacked" that we should place a relay server inside the DMZ that communicates with another WCF service inside the LAN which will then communicate with the database. The external firewall is currently configured to only allow port 443 (https) to the WCF service. The internal firewall is configured to allow SQL connections from the WCF service in the DMZ. Ignoring the obvious performance implications, I don't see the security benefit either. I'm going to reserve my judgement of this suggestion to avoid polluting the answers with my bias. Any input is appreciated. Thanks, Matt

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• Difficulty setting ArrayList to java.sql.Blob to save in DB using hibernate

  - by me_here

  I'm trying to save a java ArrayList in a database (H2) by setting it as a blob, for retrieval later. If this is a bad approach, please say - I haven't been able to find much information on this area. I have a column of type Blob in the database, and Hibernate maps to this with java.sql.Blob. The code I'm struggling with is: Drawings drawing = new Drawings(); try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = null; oos = new ObjectOutputStream(bos); oos.writeObject(plan.drawingPane21.pointList); byte[] buff = bos.toByteArray(); Blob drawingBlob = null; drawingBlob.setBytes(0, buff); drawing.setDrawingObject(drawingBlob); } catch (Exception e){ System.err.println(e); } The object I'm trying to save into a blob (plan.drawingPane21.pointList) is of type ArrayList<DrawingDot>, DrawingDot being a custom class implementing Serializable. My code is failing on the line drawingBlob.setBytes(0, buff); with a NullPointerException. Help appreciated.

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• Automation Error upon running VBA script in Excel

  - by brohjoe

  Hi guys, I'm getting an Automation error upon running VBA code in Excel 2007. I'm attempting to connect to a remote SQL Server DB and load data to from Excel to SQL Server. The error I get is, "Run-time error '-2147217843(80040e4d)': Automation error". I checked out the MSDN site and it suggested that this may be due to a bug associated with the sqloledb provider and one way to mitigate this is to use ODBC. Well I changed the connection string to reflect ODBC provider and associated parameters and I'm still getting the same error. Here is the code with ODBC as the provider: Dim cnt As ADODB.Connection Dim rst As ADODB.Recordset Dim stSQL As String Dim wbBook As Workbook Dim wsSheet As Worksheet Dim rnStart As Range Public Sub loadData() 'This was set up using Microsoft ActiveX Data Components version 6.0. 'Create ADODB connection object, open connection and construct the connection string object. Set cnt = New ADODB.Connection cnt.ConnectionString = _ "Driver={SQL Server}; Server=onlineSQLServer2010.foo.com; Database=fooDB Uid=logonalready;Pwd='helpmeOB1';" cnt.Open On Error GoTo ErrorHandler 'Open Excel and run query to export data to SQL Server. strSQL = "SELECT * INTO SalesOrders FROM OPENDATASOURCE('Microsoft.ACE.OLEDB.12.0', & _ "'Data Source=C:\Database.xlsx; Extended Properties=Excel 12.0')...[SalesOrders$]" cnt.Execute (strSQL) 'Error handling. ErrorExit: 'Reclaim memory from the connection objects Set rst = Nothing Set cnt = Nothing Exit Sub ErrorHandler: MsgBox Err.Description, vbCritical Resume ErrorExit 'clean up and reclaim memory resources. cnt.Close If CBool(cnt.State And adStateOpen) Then Set rst = Nothing Set cnt = Nothing End If End Sub

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• Pros & Cons of Google App Engine

  - by Rishi

  Pros & Cons of Google App Engine [An Updated List 21st Aug 09] Help me Compile a List of all the Advantages & Disadvantages of Building an Application on the Google App Engine Pros: 1) No Need to buy Servers or Server Space (no maintenance). 2) Makes solving the problem of scaling much easier. Cons: 1) Locked into Google App Engine ?? 2)Developers have read-only access to the filesystem on App Engine. 3)App Engine can only execute code called from an HTTP request (except for scheduled background tasks). 4)Users may upload arbitrary Python modules, but only if they are pure-Python; C and Pyrex modules are not supported. 5)App Engine limits the maximum rows returned from an entity get to 1000 rows per Datastore call. 6)Java applications may only use a subset (The JRE Class White List) of the classes from the JRE standard edition. 7)Java applications cannot create new threads. Known Issues!! http://code.google.com/p/googleappengine/issues/list Hard limits Apps per developer - 10 Time per request - 30 sec Files per app - 3,000 HTTP response size - 10 MB Datastore item size - 1 MB Application code size - 150 MB Pro or Con? App Engine's infrastructure removes many of the system administration and development challenges of building applications to scale to millions of hits. Google handles deploying code to a cluster, monitoring, failover, and launching application instances as necessary. While other services let users install and configure nearly any *NIX compatible software, App Engine requires developers to use Python or Java as the programming language and a limited set of APIs. Current APIs allow storing and retrieving data from a BigTable non-relational database; making HTTP requests; sending e-mail; manipulating images; and caching. Most existing Web applications can't run on App Engine without modification, because they require a relational database.

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• pass username and password to get-credential or run sql query without using invoke-sqlcmd in Powersh

  - by Emo

  I am trying to connect to a remote sql database and simply run the "select @@servername" query in Powershell. I'm trying to do this without using integrated security. I've been struggling with "get-credential" and "invoke-sqlcmd", only to find (I think), that you can't pass the password from "get-credential" to another Powershell cmdlets. Here's the code I'm using: add-pssnapin sqlserverprovidersnapin100 add-pssnapin sqlservercmdletsnapin100 load assemblies [Reflection.Assembly]::Load("Microsoft.SqlServer.Smo, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91") [Reflection.Assembly]::Load("Microsoft.SqlServer.SqlEnum, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91") [Reflection.Assembly]::Load("Microsoft.SqlServer.SmoEnum, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91") [Reflection.Assembly]::Load("Microsoft.SqlServer.ConnectionInfo, Version=9.0.242.0, Culture=neutral,PublicKeyToken=89845dcd8080cc91") connect to SQL Server $serverName = "HLSQLSRV03" $server = New-Object -typeName Microsoft.SqlServer.Management.Smo.Server -argumentList $serverName login using SQL authentication $server.ConnectionContext.LoginSecure=$false; $credential = Get-Credential $userName = $credential.UserName -replace("\","") $pass = $credential.Password $server.ConnectionContext.set_Login($userName) $server.ConnectionContext.set_SecurePassword($credential.Password) $DB = "Master" invoke-sqlcmd -query "select @@Servername" -database $DB -serverinstance $servername -username $username -password $pass If if just hardcode the password in at the end of the "invoke-sqlcmd" line, it works. Is this because you can't use "get-credential" with "invoke-sqlcmd"? If so...what are my alternatives? Thanks so much for you help Emo

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• Input validation in WPF

  - by irfanali-wpfexpert

  i am developing an application in wpf using MVVM design pattern. i have a listbox when an item is slected then a dialog is open having the same record in editable mode. this dialog is binded with the selected item of the list. i have apply the validation rule for textbox using IDataErrorInfo. when the user update a record on dialogbox then at every key press, the selected record in listbox is also changed. if the user press save button then i submit changes to database. but if user click cancel button then i do not submit changes to database but the list box is updated with the current updation in GUI. when i refresh the list then old value appears again. My requirement is to update the listbox only when the user hit the save button but not on every key press on dialog box. I first fill the generic list with the linq to sql classes then bind the listbox with it. Please let me know what i have to do. Thanks in advance

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• SQL Server 2005 standard filegroups / files for performance on SAN

  - by Blootac

  Ok so I've just been on a SQL Server course and we discussed the usage scenarios of multiple filegroups and files when in use over local RAID and local disks but we didn't touch SAN scenarios so my question is as follows; I currently have a 250 gig database running on SQL Server 2005 where some tables have a huge number of writes and others are fairly static. The database and all objects reside in a single file group with a single data file. The log file is also on the same volume. My interpretation is that separate data files should be used across different disks to lessen disk contention and that file groups should be used for partitioning of data. However, with a SAN you obviously don't really have the same issue of disk contention that you do with a small RAID setup (or at least we don't at the moment), and standard edition doesn't support partitioning. So in order to improve parallelism what should I do? My understanding of various Microsoft publications is that if I increase the number of data files, separate threads can act across each file separately. Which leads me to the question how many files should I have. One per core? Should I be putting tables and indexes with high levels of activity in separate file groups, each with the same number of data files as we have cores? Thank you

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• Where are tables in Mnesia located?

  - by Sanoj

  I try to compare Mnesia with more traditional databases. As I understand it tables in Mnesia can be located to: ram_copies - tables are stored in RAM only, so no durability as in ACID. disc_copies - tables are located on disc and a copy is located in RAM, so the table can not be bigger than the available memory? disc_only_copies - tables are located to disc only, so no caching in memory and worse performance? And the size of the table are limited to the size of dets or the table has to be fragmented. So if I want the performance of doing reads from RAM and the durability of writes to disc, then the size of the tables are very limited compared to a traditional RDBMS like MySQL or PostgreSQL. I know that Mnesia aren't meant to replace traditional RDBMS:s, but can it be used as a big RDBMS or do I have to look for another database? The server I will use is a VPS with limited amount of memory, around 512MB, but I want good database performance. Are disc_copies and the other types of tables in Mnesia so limited as I have understood?

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