Search Results

Search found 31588 results on 1264 pages for 'linq to sql designer'.

Page 173/1264 | < Previous Page | 169 170 171 172 173 174 175 176 177 178 179 180  | Next Page >

  • What would be the optimal disk config for SQL Server 2008 R2?

    - by Kev
    We have a new Dell R710 server that came with the following storage configuration: 8 x 146GB SAS 10k 6Gbps disks 1 x Perc H700 Integrated Controller (2 x 4 disks - 2 ports each supporting 4 disks) What would be the optimal configuration if we were just after performance? What would be the optimal configuration if we were after performance but wanted data resilience. As per 2 above but with a hot standby disk? We plan to run Windows 2008 R2 and SQL Server 2008 R2. Maximising storage capacity isn't a prime concern.

    Read the article

  • How can I grant read-only access to my SQL Server 2008 database?

    - by Adrian Grigore
    Hi, I'm trying to grant read-only access (in other words: select queries only) to a user account on my SQL Server 2008 R2 database. Which rights do I have to grant to the user to make this work? I've tried several kinds of combinations of permissions on the server and the database itself, but in all cases the user could still run update queries or he could not run any queries (not even select) at all. The error message I always got was The server principal "foo" is not able to access the database "bar" under the current security context. Thanks for your help, Adrian

    Read the article

  • LINQ to Twitter Queries with LINQPad

    - by Joe Mayo
    LINQPad is a popular utility for .NET developers who use LINQ a lot.  In addition to standard SQL queries, LINQPad also supports other types of LINQ providers, including LINQ to Twitter.  The following sections explain how to set up LINQPad for making queries with LINQ to Twitter. LINQPad comes in a couple versions and this example uses LINQPad4, which runs on the .NET Framework 4.0. 1. The first thing you'll need to do is set up a reference to the LinqToTwitter.dll. From the Query menu, select query properties. Click the Browse button and find the LinqToTwitter.dll binary. You should see something similar to the Query Properties window below. 2. While you have the query properties window open, add the namespace for the LINQ to Twitter types.  Click the Additional Namespace Imports tab and type in LinqToTwitter. The results are shown below: 3. The default query type, when you first start LINQPad, is C# Expression, but you'll need to change this to support multiple statements.  Change the Language dropdown, on the Main window, to C# Statements. 4. To query LINQ to Twitter, instantiate a TwitterContext, by typing the following into the LINQPad Query window: var ctx = new TwitterContext(); Note: If you're getting syntax errors, go back and make sure you did steps #2 and #3 properly. 5. Next, add a query, but don't materialize it, like this: var tweets = from tweet in ctx.Status where tweet.Type == StatusType.Public select new { tweet.Text, tweet.Geo, tweet.User }; 6. Next, you want the output to be displayed in the LINQPad grid, so do a Dump, like this: tweets.Dump(); The following image shows the final results:   That was an unauthenticated query, but you can also perform authenticated queries with LINQ to Twitter's support of OAuth.  Here's an example that uses the PinAuthorizer (type this into the LINQPad Query window): var auth = new PinAuthorizer { Credentials = new InMemoryCredentials { ConsumerKey = "", ConsumerSecret = "" }, UseCompression = true, GoToTwitterAuthorization = pageLink => Process.Start(pageLink), GetPin = () => { // this executes after user authorizes, which begins with the call to auth.Authorize() below. Console.WriteLine("\nAfter you authorize this application, Twitter will give you a 7-digit PIN Number.\n"); Console.Write("Enter the PIN number here: "); return Console.ReadLine(); } }; // start the authorization process (launches Twitter authorization page). auth.Authorize(); var ctx = new TwitterContext(auth, "https://api.twitter.com/1/", "https://search.twitter.com/"); var tweets = from tweet in ctx.Status where tweet.Type == StatusType.Public select new { tweet.Text, tweet.Geo, tweet.User }; tweets.Dump(); This code is very similar to what you'll find in the LINQ to Twitter downloadable source code solution, in the LinqToTwitterDemo project.  For obvious reasons, I changed the value assigned to ConsumerKey and ConsumerSecret, which you'll have to obtain by visiting http://dev.twitter.com and registering your application. One tip, you'll probably want to make this easier on yourself by creating your own DLL that encapsulates all of the OAuth logic and then call a method or property on you custom class that returns a fully functioning TwitterContext.  This will help avoid adding all this code every time you want to make a query. Now, you know how to set up LINQPad for LINQ to Twitter, perform unauthenticated queries, and perform queries with OAuth. Joe

    Read the article

  • Is there a simple way to backup and restore all Microsoft SQL Server database objects related to a p

    - by Nathan Hartley
    I would like to backup, not only the databases that belong to a particular application living on a shared server, but also, those things that get stored outside of the database; the server accounts, jobs, maintenance plans and whatever else I can't think of at the moment. This backup should be complete enough that it's corresponding restore will recreate the entire application on a different SQL server. This seems like a problem others must have dealt with in the past. So before I embark on creating custom Powershell scripts for each application, I have come to ask you... Can you help?

    Read the article

  • How to configure/save layout of SQL Server's Log File Viewer?

    - by gernblandston
    When I'm viewing the job history of a particular SQL Agent Job, I typically want to see whether it succeeded, its duration and maybe the duration of the individual steps of the job. When I open the history in the Log File Viewer, I always need to scroll over and shrink the 'Message' column and drag the 'Duration' column over next to the 'Step Name' column. Is there a way to configure the layout of the Log File Viewer (e.g. reposition columns, resize columns) and save it for future sessions? Thanks!

    Read the article

  • How do I capture a 10053 trace for a SQL statement called in a PL/SQL package?

    - by Maria Colgan
    Traditionally if you wanted to capture an Optimizer trace (10053) for a SQL statement you would issue an alter session command to switch on a 10053 trace for that entire session, and then issue the SQL statement you wanted to capture the trace for. Once the statement completed you would exit the session to disable the trace. You would then look in the USER_DUMP_DEST directory for the trace file. But what if the SQL statement you were interested  in was actually called as part of a PL/SQL package? Oracle Database 11g, introduced a new diagnostic events infrastructure, which greatly simplifies the task of generating a 10053 trace for a specific SQL statement in a PL/SQL package. All you will need to know is the SQL_ID for the statement you are interested in. Instead of turning on the trace event for the entire session you can now switch it on for a specific SQL ID. Oracle will then capture a 10053 trace for the corresponding SQL statement when it is issued in that session. Remember the SQL statement still has to be hard parsed for the 10053 trace to be generated.  Let's begin our example by creating a PL/SQL package called 'cal_total_sales'. The SQL statement we are interested in is the same as the one in our original example, SELECT SUM(AMOUNT_SOLD) FROM SALES WHERE CUST_ID = :B1. We need to know the SQL_ID of this SQL statement to set up the trace, and we can find in V$SQL. We now have everything we need to generate the trace. Finally  you would look in the USER_DUMP_DEST directory for the trace file with the name you specified. Maria Colgan+

    Read the article

  • SQL Server 2008 CPU usage goes to 100% - troubleshooting help needed?

    - by Ali
    I have a fairly powerful database server having SQL Server 2008 R2 installed. There is only one database on it which is being accessed from 2 servers (around 5/6 applications). The problem is as soon as applications start pointing to the database, system's CPU usage goes upto 100% with sqlserver itself using 95+%. I have checked profiler, there aren't any heavy queries running there. I have checked active connections, they are hardly 150. Still CPU usage is around 100% and applications are experiencing slow response/connection to database server are getting refused. Database grus, I really need some ideas here. Thanks.

    Read the article

  • SQL Server tempdb size seems large, is this normal?

    - by Abe Miessler
    From what I understand the system database is used to hold temporary tables, intermediate results and other temporary information. On one of my database instances I have a tempdb that is seems very large (30GB). This database has not been modified (as in "last modified date" on the mdf file) in over a week. Is it normal to have the temp db remain that large for that long of a period? It seems to me that it should be updating fairly often and returning space that it is using fairly quickly... Am I way off here or is SQL Server doing something weird? FYI: This is a SharePoint 2010 database, not sure if that makes a difference.

    Read the article

  • Configuring SQL Server Management Studio to use Windows Integrated Authentication &hellip; from non-

    - by Enrique Lima
    Did you know you can pass your Windows credentials to SQL Server even when working from a workstation that is not joined to a domain? Here is how … From Start, then click All Programs, find Microsoft SQL Server (version 2005 or 2008). Once there, do a right-click on SQL Server Management Studio, then click on Properties Now, follow below to modify the entry for Target: Now the real task (we will be using the runas command) … Modify the shortcut’s target as follows, and remember to replace <domain\user> with the values that correspond to your environment : x64 SQL Server 2008 C:\Windows\System32\runas.exe /user:<domain\user> /netonly "C:\Program Files (x86)\Microsoft SQL Server\100\Tools\binn\VSShell\Common7\IDE\Ssms.exe -nosplash" SQL Server 2005 C:\Windows\System32\runas.exe /user:<domain\user> /netonly "C:\Program Files (x86)\Microsoft SQL Server\90\Tools\binn\VSShell\Common7\IDE\SqlWb.exe -nosplash" x86 SQL Server 2008 C:\Windows\System32\runas.exe /user:<domain\user> /netonly "C:\Program Files\Microsoft SQL Server\100\Tools\binn\VSShell\Common7\IDE\Ssms.exe -nosplash" SQL Server 2005 C:\Windows\System32\runas.exe /user:<domain\user> /netonly "C:\Program Files\Microsoft SQL Server\90\Tools\binn\VSShell\Common7\IDE\SqlWb.exe -nosplash" Since we modified the shortcut, we will need to fix the icon for SSMS.  We will fix it by pressing the Change Icon… button and pointing to the original “icon” providers. It is the executables for SSMS that hold the icon information, so we need to point to … x64 SQL Server 2008 %ProgramFiles% (x86)\Microsoft SQL Server\100\Tools\Binn\VSShell\Common7\IDE\Ssms.exe SQL Server 2005 C:\Program Files (x86)\Microsoft SQL Server\90\Tools\binn\VSShell\Common7\IDE\SqlWb.exe x86 SQL Server 2008 %ProgramFiles%\Microsoft SQL Server\100\Tools\Binn\VSShell\Common7\IDE\Ssms.exe SQL Server 2005 C:\Program Files\Microsoft SQL Server\90\Tools\binn\VSShell\Common7\IDE\SqlWb.exe When you start SSMS from a modified shortcut, you’ll be prompted for your domain password: SSMS will show up stating a different account in the username box, but the parameters from the configuration you are doing above do work and will pass on correctly.

    Read the article

  • SQL Server 2012 and SQLMail - will it still work?

    - by Kharlos Dominguez
    We are considering upgrading our SQL Server, which is currently running 2005. We use SQLMail heavily in the organization, both to send e-mails and to import some into a database. I've read on various places that SQLMail was deprecated and superseded by "Database Mail". I'm confused because this MS page: http://msdn.microsoft.com/en-us/library/bb402904.aspx seems to imply that it would still work? I understand the dangers of SQLMail but we do not have the resources to rewrite the scripts right now and would prefer to do it later on. Does SQLMail still work in 2012, and if not, how easy is it to replace with Database Mail, both for reading and sending e-mails?

    Read the article

  • SQL Server 2012 Service Pack 2 Cumulative Update #1 is available!

    - by AaronBertrand
    The SQL Server team has released SQL Server 2012 SP2 Cumulative Update #1. This cumulative updates Service Pack 2 to include the fixes from SP1 CU#10 and a few from CU#11, including the fix for the online index rebuild corruption issue I discussed recently on SQLPerformance.com . It also marks the first time in the SQL Server 2012 timeframe that both cumulative update branches are on roughly the same schedule, which makes many of us happy I'm sure. :-) KB Article: KB #2976982 Build # is 11.0.5532...(read more)

    Read the article

  • Nested Entities and calculation on leaf entity property - SQL or NoSQL approach

    - by Chandu
    I am working on a hobby project called Menu/Recipe Management. This is how my entities and their relations look like. A Nutrient has properties Code and Value An Ingredient has a collection of Nutrients A Recipe has a Collection of Ingredients and occasionally can have a collection of other recipes A Meal has a Collection of Recipes and Ingredients A Menu has a Collection of Meals The relations can be depicted as In one of the pages, for a selected menu I need to display the effective nutrients information calculated based on its constituents (Meals, Recipes, Ingredients and the corresponding nutrients). As of now am using SQL Server to store the data and I am navigating the chain from my C# code, starting from each meal of the menu and then aggregating the nutrient values. I think this is not an efficient way as this calculation is being done every time the page is requested and the constituents change occasionally. I was thinking about a having a background service that maintains a table called MenuNutrients ({MenuId, NutrientId, Value}) and will populate/update this table with the effective nutrients when any of the component (Meal, Recipe, Ingredient) changes. I feel that a GraphDB would be a good fit for this requirement, but my exposure to NoSQL is limited. I want to know what are the alternative solutions/approaches to this requirement of displaying the nutrients of a given menu. Hope my description of the scenario is clear.

    Read the article

  • Is there any way to send a column value from outer query to inner sub query? [closed]

    - by chetan
    'Discussions' table schema title description desid replyto upvote downvote views browser used a1 none 1 1 12 - bad topic b2 a1 2 3 14 sql database a3 none 4 5 34 - crome b4 a3 3 4 12 The above table has two types of content types Main Topics and Comments. Unique content identifier 'desid' used to identify that its a main topic or a comment. 'desid' starts with 'a' for Main Topic and for comment 'desid' starts with 'b'. For comment 'replyto' is the 'desid' of main topic to which this comment is associated. I like to find out the list of the top main topics that are arranged on the basis of (upvote+downvote+visits+number of comments to it) addition. The following query gives top topics list in order of (upvote+downvote+visits) select * with highest number of upvote+downvote+views by query "select * from [DB_user1212].[dbo].[discussions] where desid like 'a%' order by (upvote+downvote+visited) desc For (comments+upvote+downvote+views ) I tried select * from [DB_user1212].[dbo].[discussions] where desid like 'a%' order by ((select count(*) from [DB_user1212].[dbo].[discussions] where replyto = desid )+upvote+downvote+visited) desc but it didn't work because its not possible to send desid from outer query to inner subquery. How to solve this? Please note that I want solution in query language only.

    Read the article

  • Could SQL Server 2008 replication be used with NLB to allow unlimited scaling of reporting servers?

    - by John Keranos
    We are currently using transactional replication in SQL Server 2008 to keep a secondary reporting server synchronized with a primary database server. This has been working weel and keeps some of the load off the primary server. Would it be possible to scale this solution to multiple reporting servers? We're expecting an increased load of read-only queries and it would be nice to be able to add reporting servers as needed. The general idea was the following: Each reporting server would use a "pull" subscription to get the data from the primary database publication. These reporting databases could be a couple of minutes behind the primary server without it being an issue. The reporting servers would be NLB'd together. All read-only queries would be directed to the NLB which should spread the load across the servers.

    Read the article

  • Most common parts of a SELECT SQL query?

    - by jnrbsn
    I'm writing a function that generates a SELECT SQL query. (I'm not looking for a tool that already does this.) My function currently takes the following arguments which correspond to different parts of the SELECT query (the base table name is already known): where order fields joins group limit All of these arguments will be optional so that the function generates something like this by default: SELECT * FROM `table_name` I want to order the arguments so that the most often used parts of a SELECT query are first. That way the average call to the function will use as few of the arguments as possible rather than passing a null value or something like that to skip an argument. For example, if someone wanted to use the 1st and 3rd arguments but not the rest, they might have to pass a null value as the 2nd argument in order to skip it. So, for general purpose use, how should I order the arguments? Edit: To be more precise, out of the query parts I listed above, what is the order from most used to least used? Also, I'm not looking for solutions that allow me to not have to specify the order. Edit #2: The "fields" argument will default to "*" (i.e all fields/columns).

    Read the article

  • How to setup users for desktop app with SQL Azure as backend?

    - by Manuel
    I'm considering SQL Azure as DB for a new application I'm developing. The reason I want to go with Azure is because I don't want to have to maintain yet another database(s) and I want my users to be able to access the data from anywhere. The problem is that I'm not clear regarding how to users will connect. The application is a basic CRUD type of windows app. I've read that you need to add your IP to SQL Azure's firewall to connect to it, but I don't know if it's only for administration purposes only. Can anyone clarify if anyone (anywhere) can access the data with the proper credentials? Which of the following scenarios would work best (if at all)? A) Add each user to SQL Azure and have the app connect directly to Azure as if it was connecting to SQL Server B) Add an anonymous user SQL Azure and pass the real user's password/hash with every call so the Azure database can service the requests accordingly. C) Put a WCF service in between so that it handles the authentication stuff. The service will only serve the appropriate information to the user given his/her authentication and SQL Azure would be open to the service exclusively. D) - ideas are welcomed - This is confusing because all Azure examples I see are for websites. I have a hard time believing SQL Azure wouldn't handle the case of desktop apps connecting to it. So what's the best practice?

    Read the article

  • How do I restore a SQL Server database from last night's full backup and the active transaction log file?

    - by Dylan Beattie
    I have been told that it's good practise to keep your SQL Server data files and log files on physically separate disks, because it'll allow you to recover your data to the point of failure if the data drive fails. So... let's say that mydata.mdf is on drive D:, and my mydata_log.ldf is on drive E:, and it's 16:45, and drive D: has just died horribly. So - I have last night's full backup (mydata.bak). I have hourly transaction-log backups that will bring the data back up to 16:00... but that means I'll lose 45 minutes worth of updates. I still have mydata_log.ldf on the E: drive, which should contain EVERY transaction that was committed right up to the point where the drive failed. How do I go about recreating the database and restoring data from the backup file and the live transaction log, so I don't lose any updates? Is this possible?

    Read the article

  • If a SQL Server Replication Distributor and Subscriber are on the same server, should a PUSH or PULL subsciption be used?

    - by userx
    Thanks in advance for any help. I'm setting up a new Microsoft SQL Server replication and I have the Distributor and Subscriber running on the same server. The Publisher is on a remote server (as it is a production database and MS recommends that for high volumes, the Distributor should be remote). I don't know much about the inner workings of PUSH vs PULL subscriptions, but my gut tells me that a PUSH subscription would be less resource intensive because (1) the Distributor is already remote, so this shouldn't negatively effect the Publisher and (2) pushing the transactions from the Distributor to the Subscriber is more efficient than the Subscriber polling the Distribution database. Does any one have any resources or insight into PUSH vs PULL which would recommend one over the other? Is there really going to be that big of a difference in performance / reliability / security?

    Read the article

  • SQL RDBMS : one query or multiple calls

    - by None None
    After looking around the internet, I decided to create DAOs that returned objects (POJOs) to the calling business logic function/method. For example: a Customer object with a Address reference would be split in the RDBMS into two tables; Customer and ADDRESS. The CustomerDAO would be in charge of joining the data from the two tables and create both an Address POJO and Customer POJO adding the address to the customer object. Finally return the fulll Customer POJO. Simple, however, now i am at a point where i need to join three or four tables and each representing an attribute or list of attributes for the resulting POJO. The sql will include a group by but i will still result with multiple rows for the same pojo, because some of the tables are joining a one to many relationship. My app code will now have to loop through all the rows trying to figure out if the rows are the same with different attributes or if the record should be a new POJO. Should I continue to create my daos using this technique or break up my Pojo creation into multiple db calls to make the code easier to understand and maintain?

    Read the article

  • Oddities in Linq-to-SQL generated code related to property change/changing events

    - by Lasse V. Karlsen
    I'm working on creating my own Linq-to-Sql generated classes in order to learn the concepts behind it all. I have some questions, if anyone knows the answer to one or more of these I'd be much obliged. The code below, and thus the questions, are from looking at code generated by creating a .DBML file in the Visual Studio 2010 designer, and inspecting the .Designer.cs file afterwards. 1. Why is INotifyPropertyChanging not passing the property name The event raising method is defined like this: protected virtual void SendPropertyChanging() Why isn't the name of the property that is changing passed to the event here? It is defined to be part of the EventArgs descendant that is passed to the event handler, but the method only passes an empty such value to it. 2. Why are the EntitySet<X> attach/detach methods not raising property changed? For an EntitySet<X> reference, the following two methods are generated: private void attach_EmailAddress1s(EmailAddress1 entity) { this.SendPropertyChanging(); entity.Person1 = this; } private void detach_EmailAddress1s(EmailAddress1 entity) { this.SendPropertyChanging(); entity.Person1 = null; } Why isn't SendPropertyChanged also called here? I'm sure I have more questions later, but for now these will suffice :)

    Read the article

  • Login failed for user 'DOMAIN\MACHINENAME$'

    - by sah302
    I know this is almost duplicate of : http://stackoverflow.com/questions/1269706/the-error-login-failed-for-user-nt-authority-iusr-in-asp-net-and-sql-server-2 and http://stackoverflow.com/questions/97594/login-failed-for-user-username-system-data-sqlclient-sqlexception-with-linq-i but some things don't add up compared to other appliations on my server and I am not sure why. Boxes being used: Web Box SQL Box SQL Test Box My Application: I've got aASP.NET Web Application, which references a class library that uses LINQ-to-SQL. Connection string set up properly in the class library. As per http://stackoverflow.com/questions/97594/login-failed-for-user-username-system-data-sqlclient-sqlexception-with-linq-i I also added this connection string to the Web Application. The connection string uses SQL credentials as so (in both web app and class library): <add name="Namespace.My.MySettings.ConnectionStringProduction" connectionString="Data Source=(SQL Test Box);Initial Catalog=(db name);Persist Security Info=True;User ID=ID;Password=Password" providerName="System.Data.SqlClient" /> This connection confirmed as working via adding it to server explorer. This is the connection string my .dbml file is using. The problem: I get the following error: System.Data.SqlClient.SqlException: Login failed for user 'DOMAIN\MACHINENAME$'. Now referencing this http://stackoverflow.com/questions/1269706/the-error-login-failed-for-user-nt-authority-iusr-in-asp-net-and-sql-server-2 it says that's really the local network service and using any other non-domain name will not work. But I am confused because I've checked both SQL Box and SQL Test Box SQL Management Studio and both have NT AUTHORITY/NETWORK SERVICE under Security - Logins, at the database level, that isn't listed under Security - Users, but at the database level Security - Users I have the user displayed in the connection string. At NTFS level on web server, the permissions have NETWORK SERVICE has full control. The reason why I am confused is because I have many other web applications on my Web Server, that reference databases on both SQL Box and SQL Test Box, and they all work. But I cannot find a difference between them and my current application, other than I am using a class library. Will that matter? Checking NTFS permissions, setup of Security Logins at the server and databases levels, connection string and method of connecting (SQL Server credentials), and IIS application pool and other folder options, are all the same. Why do these applications work without adding the machinename$ to the permissions of either of my SQL boxes? But that is what the one link is telling me to do to fix this problem.

    Read the article

  • Getting results in a result set from dynamic SQL in Oracle

    - by msorens
    This question is similar to a couple others I have found on StackOverflow, but the differences are signficant enough to me to warrant a new question, so here it is: I want to obtain a result set from dynamic SQL in Oracle and then display it as a result set in a SqlDeveloper-like tool, just as if I had executed the dynamic SQL statement directly. This is straightforward in SQL Server, so to be concrete, here is an example from SQL Server that returns a result set in SQL Server Management Studio or Query Explorer: EXEC sp_executesql N'select * from countries' Or more properly: DECLARE @stmt nvarchar(100) SET @stmt = N'select * from countries' EXEC sp_executesql @stmt The question "How to return a resultset / cursor from a Oracle PL/SQL anonymous block that executes Dynamic SQL?" addresses the first half of the problem--executing dynamic SQL into a cursor. The question "How to make Oracle procedure return result sets" provides a similar answer. Web search has revealed many variations of the same theme, all addressing just the first half of my question. I found this post explaining how to do it in SqlDeveloper, but that uses a bit of functionality of SqlDeveloper. I am actually using a custom query tool so I need the solution to be self-contained in the SQL code. This custom query tool similarly does not have the capability to show output of print (dbms_output.put_line) statements; it only displays result sets. Here is yet one more possible avenue using 'execute immediate...bulk collect', but this example again renders the results with a loop of dbms_output.put_line statements. This link attempts to address the topic but the question never quite got answered there either. Assuming this is possible, I will add one more condition: I would like to do this without having to define a function or procedure (due to limited DB permissions). That is, I would like to execute a self-contained PL/SQL block containing dynamic SQL and return a result set in SqlDeveloper or a similar tool. So to summarize: I want to execute an arbitrary SQL statement (hence dynamic SQL). The platform is Oracle. The solution must be a PL/SQL block with no procedures or functions. The output must be generated as a canonical result set; no print statements. The output must render as a result set in SqlDeveloper without using any SqlDeveloper special functionality. Any suggestions?

    Read the article

  • Finally! Entity Framework working in fully disconnected N-tier web app

    - by oazabir
    Entity Framework was supposed to solve the problem of Linq to SQL, which requires endless hacks to make it work in n-tier world. Not only did Entity Framework solve none of the L2S problems, but also it made it even more difficult to use and hack it for n-tier scenarios. It’s somehow half way between a fully disconnected ORM and a fully connected ORM like Linq to SQL. Some useful features of Linq to SQL are gone – like automatic deferred loading. If you try to do simple select with join, insert, update, delete in a disconnected architecture, you will realize not only you need to make fundamental changes from the top layer to the very bottom layer, but also endless hacks in basic CRUD operations. I will show you in this article how I have  added custom CRUD functions on top of EF’s ObjectContext to make it finally work well in a fully disconnected N-tier web application (my open source Web 2.0 AJAX portal – Dropthings) and how I have produced a 100% unit testable fully n-tier compliant data access layerfollowing the repository pattern. http://www.codeproject.com/KB/linq/ef.aspx In .NET 4.0, most of the problems are solved, but not all. So, you should read this article even if you are coding in .NET 4.0. Moreover, there’s enough insight here to help you troubleshoot EF related problems. You might think “Why bother using EF when Linq to SQL is doing good enough for me.” Linq to SQL is not going to get any innovation from Microsoft anymore. Entity Framework is the future of persistence layer in .NET framework. All the innovations are happening in EF world only, which is frustrating. There’s a big jump on EF 4.0. So, you should plan to migrate your L2S projects to EF soon.

    Read the article

  • LINQ-to-SQL: ExecuteQuery(Type, String) populates one field, but not the other

    - by Daniel Schaffer
    I've written an app that I use as an agent to query data from a database and automatically load it into my distributed web cache. I do this by specifying an sql query and a type in a configuration. The code that actually does the querying looks like this: List<Object> result = null; try { result = dc.ExecuteQuery(elementType, entry.Command).OfType<Object>().ToList(); } catch (Exception ex) { HandleException(ex, WebCacheAgentLogEvent.DatabaseExecutionError); continue; } elementType is a System.Type created from the type specified in the configuration (using Type.GetType()), and entry.Command is the SQL query. The specific entity type I'm having an issue with looks like this: public class FooCount { [Column(Name = "foo_id")] public Int32 FooId { get; set; } [Column(Name = "count")] public Int32 Count { get; set; } } The SQL query looks like this: select foo_id as foo_id, sum(count) as [count] from foo_aggregates group by foo_id order by foo_id For some reason, when the query is executed, the "Count" property ends up populated, but not the "FooId" property. I tried running the query myself, and the correct column names are returned, and the column names match up with what I've specified in my mapping attributes. Help!

    Read the article

< Previous Page | 169 170 171 172 173 174 175 176 177 178 179 180  | Next Page >