sql source control - Page 278

Selecting records in SQL that have the minimum value for that record based on another field

- by Ryan

I have a set of data, and while the number of fields and tables it joins with is quite complex, I believe I can distill my problem down using the required fields/tables here for illustration regarding this particular problem. I have three tables: ClientData, Sources, Prices Here is what my current query looks like before selecting the minimum value: select c.RecordID, c.Description, s.Source, p.Price, p.Type, p.Weight from ClientData c inner join Sources s ON c.RecordID = s.RecordID inner join Prices p ON s.SourceID = p.SourceID This produces the following result: RecordID Description Source Price Type Weight ============================================================= 001002003 ABC Common Stock Vendor 1 104.5 Close 1 001002003 ABC Common Stock Vendor 1 103 Bid 2 001002003 ABC Common Stock Vendor 2 106 Close 1 001002003 ABC Common Stock Vendor 2 100 Unknwn 0 111222333 DEF Preferred Stk Vendor 3 80 Bid 2 111222333 DEF Preferred Stk Vendor 3 82 Mid 3 111222333 DEF Preferred Stk Vendor 2 81 Ask 4 What I am trying to do is display prices that belong to the same record which have the minimum non-zero weight for that record (so the weight must be greater than 0, but it has to be the minimum from amongst the remaining weights). So in the above example, for record 001002003 I would want to show the close prices from Vendor 1 and Vendor 2 because they both have a weight of 1 (the minimum weight for that record). But for 111222333 I would want to show just the bid price from Vendor 3 because its weight of 2 is the minimum, non-zero for that record. The result that I'm after would like like: RecordID Description Source Price Type Weight ============================================================= 001002003 ABC Common Stock Vendor 1 104.5 Close 1 001002003 ABC Common Stock Vendor 2 106 Close 1 111222333 DEF Preferred Stk Vendor 3 80 Bid 2 Any ideas on how to achieve this? EDIT: This is for SQL Compact Edition.

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Creating an ASP.NET report using Visual Studio 2010 - Part 3

- by rajbk

We continue building our report in this three part series. Creating an ASP.NET report using Visual Studio 2010 - Part 1 Creating an ASP.NET report using Visual Studio 2010 - Part 2 Adding the ReportViewer control and filter drop downs. Open the source code for index.aspx and add a ScriptManager control. This control is required for the ReportViewer control. Add a DropDownList for the categories and suppliers. Add the ReportViewer control. The markup after these steps is shown below. <div> <asp:ScriptManager ID="smScriptManager" runat="server"> </asp:ScriptManager> <div id="searchFilter"> Filter by: Category : <asp:DropDownList ID="ddlCategories" runat="server" /> and Supplier : <asp:DropDownList ID="ddlSuppliers" runat="server" /> </div> <rsweb:ReportViewer ID="rvProducts" runat="server"> </rsweb:ReportViewer> </div> The design view for index.aspx is shown below. The dropdowns will display the categories and suppliers in the database. Changing the selection in the drop downs will cause the report to be filtered by the selections in the dropdowns. You will see how to do this in the next steps. Attaching the RDLC to the ReportViewer control by clicking on the top right of the control, going to Report Viewer tasks and selecting Products.rdlc. Resize the ReportViewer control by dragging at the bottom right corner. I set mine to 800px x 500px. You can also set this value in source view. Defining the data sources. We will now define the Data Source used to populate the report. Go back to the “ReportViewer Tasks” and select “Choose Data Sources” Select a “New data source..” Select “Object” and name your Data Source ID “odsProducts” In the next screen, choose “ProductRepository” as your business object. Choose “GetProductsProjected” in the next screen. The method requires a SupplierID and CategoryID. We will set these so that our data source gets the values from the drop down lists we defined earlier. Set the parameter source to be of type “Control” and set the ControlIDs to be ddlSuppliers and ddlCategories respectively. Your screen will look like this: We are now going to define the data source for our drop downs. Select the ddlCategory drop down and pick “Choose Data Source”. Pick “Object” and give it an id “odsCategories” In the next screen, choose “ProductRepository” Select the GetCategories() method in the next screen. Select “CategoryName” and “CategoryID” in the next screen. We are done defining the data source for the Category drop down. Perform the same steps for the Suppliers drop down. Select each dropdown and set the AppendDataBoundItems to true and AutoPostback to true. The AppendDataBoundItems is needed because we are going to insert an “All“ list item with a value of empty. Go to each drop down and add this list item markup as shown below> Finally, double click on each drop down in the designer and add the following code in the code behind. This along with the “Autopostback= true” attribute refreshes the report anytime a drop down is changed. protected void ddlCategories_SelectedIndexChanged(object sender, EventArgs e) { rvProducts.LocalReport.Refresh(); } protected void ddlSuppliers_SelectedIndexChanged(object sender, EventArgs e) { rvProducts.LocalReport.Refresh(); } Compile your report and run the page. You should see the report rendered. Note that the tool bar in the ReportViewer control gives you a couple of options including the ability to export the data to Excel, PDF or word. Conclusion Through this three part series, we did the following: Created a data layer for use by our RDLC. Created an RDLC using the report wizard and define a dataset for the report. Used the report design surface to design our report including adding a chart. Used the ReportViewer control to attach the RDLC. Connected our ReportWiewer to a data source and take parameter values from the drop downlists. Used AutoPostBack to refresh the reports when the dropdown selection was changed. RDLCs allow you to create interactive reports including drill downs and grouping. For even more advanced reports you can use Microsoft® SQL Server™ Reporting Services with RDLs. With RDLs, the report is rendered on the report server instead of the web server. Another nice thing about RDLs is that you can define a parameter list for the report and it gets rendered automatically for you. RDLCs and RDLs both have their advantages and its best to compare them and choose the right one for your requirements. Download VS2010 RTM Sample project NorthwindReports.zip Alfred Borden: Are you watching closely?

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Performance considerations for common SQL queries

- by Jim Giercyk

Originally posted on: http://geekswithblogs.net/NibblesAndBits/archive/2013/10/16/performance-considerations-for-common-sql-queries.aspxSQL offers many different methods to produce the same results. There is a never-ending debate between SQL developers as to the “best way” or the “most efficient way” to render a result set. Sometimes these disputes even come to blows….well, I am a lover, not a fighter, so I decided to collect some data that will prove which way is the best and most efficient. For the queries below, I downloaded the test database from SQLSkills: http://www.sqlskills.com/sql-server-resources/sql-server-demos/. There isn’t a lot of data, but enough to prove my point: dbo.member has 10,000 records, and dbo.payment has 15,554. Our result set contains 6,706 records. The following queries produce an identical result set; the result set contains aggregate payment information for each member who has made more than 1 payment from the dbo.payment table and the first and last name of the member from the dbo.member table. /*************/ /* Sub Query */ /*************/ SELECT a.[Member Number] , m.lastname , m.firstname , a.[Number Of Payments] , a.[Average Payment] , a.[Total Paid] FROM ( SELECT member_no 'Member Number' , AVG(payment_amt) 'Average Payment' , SUM(payment_amt) 'Total Paid' , COUNT(Payment_No) 'Number Of Payments' FROM dbo.payment GROUP BY member_no HAVING COUNT(Payment_No) > 1 ) a JOIN dbo.member m ON a.[Member Number] = m.member_no /***************/ /* Cross Apply */ /***************/ SELECT ca.[Member Number] , m.lastname , m.firstname , ca.[Number Of Payments] , ca.[Average Payment] , ca.[Total Paid] FROM dbo.member m CROSS APPLY ( SELECT member_no 'Member Number' , AVG(payment_amt) 'Average Payment' , SUM(payment_amt) 'Total Paid' , COUNT(Payment_No) 'Number Of Payments' FROM dbo.payment WHERE member_no = m.member_no GROUP BY member_no HAVING COUNT(Payment_No) > 1 ) ca /********/ /* CTEs */ /********/ ; WITH Payments AS ( SELECT member_no 'Member Number' , AVG(payment_amt) 'Average Payment' , SUM(payment_amt) 'Total Paid' , COUNT(Payment_No) 'Number Of Payments' FROM dbo.payment GROUP BY member_no HAVING COUNT(Payment_No) > 1 ), MemberInfo AS ( SELECT p.[Member Number] , m.lastname , m.firstname , p.[Number Of Payments] , p.[Average Payment] , p.[Total Paid] FROM dbo.member m JOIN Payments p ON m.member_no = p.[Member Number] ) SELECT * FROM MemberInfo /************************/ /* SELECT with Grouping */ /************************/ SELECT p.member_no 'Member Number' , m.lastname , m.firstname , COUNT(Payment_No) 'Number Of Payments' , AVG(payment_amt) 'Average Payment' , SUM(payment_amt) 'Total Paid' FROM dbo.payment p JOIN dbo.member m ON m.member_no = p.member_no GROUP BY p.member_no , m.lastname , m.firstname HAVING COUNT(Payment_No) > 1 We can see what is going on in SQL’s brain by looking at the execution plan. The Execution Plan will demonstrate which steps and in what order SQL executes those steps, and what percentage of batch time each query takes. SO….if I execute all 4 of these queries in a single batch, I will get an idea of the relative time SQL takes to execute them, and how it renders the Execution Plan. We can settle this once and for all. Here is what SQL did with these queries: Not only did the queries take the same amount of time to execute, SQL generated the same Execution Plan for each of them. Everybody is right…..I guess we can all finally go to lunch together! But wait a second, I may not be a fighter, but I AM an instigator. Let’s see how a table variable stacks up. Here is the code I executed: /********************/ /* Table Variable */ /********************/ DECLARE @AggregateTable TABLE ( member_no INT , AveragePayment MONEY , TotalPaid MONEY , NumberOfPayments MONEY ) INSERT @AggregateTable SELECT member_no 'Member Number' , AVG(payment_amt) 'Average Payment' , SUM(payment_amt) 'Total Paid' , COUNT(Payment_No) 'Number Of Payments' FROM dbo.payment GROUP BY member_no HAVING COUNT(Payment_No) > 1 SELECT at.member_no 'Member Number' , m.lastname , m.firstname , at.NumberOfPayments 'Number Of Payments' , at.AveragePayment 'Average Payment' , at.TotalPaid 'Total Paid' FROM @AggregateTable at JOIN dbo.member m ON m.member_no = at.member_no In the interest of keeping things in groupings of 4, I removed the last query from the previous batch and added the table variable query. Here’s what I got: Since we first insert into the table variable, then we read from it, the Execution Plan renders 2 steps. BUT, the combination of the 2 steps is only 22% of the batch. It is actually faster than the other methods even though it is treated as 2 separate queries in the Execution Plan. The argument I often hear against Table Variables is that SQL only estimates 1 row for the table size in the Execution Plan. While this is true, the estimate does not come in to play until you read from the table variable. In this case, the table variable had 6,706 rows, but it still outperformed the other queries. People argue that table variables should only be used for hash or lookup tables. The fact is, you have control of what you put IN to the variable, so as long as you keep it within reason, these results suggest that a table variable is a viable alternative to sub-queries. If anyone does volume testing on this theory, I would be interested in the results. My suspicion is that there is a breaking point where efficiency goes down the tubes immediately, and it would be interesting to see where the threshold is. Coding SQL is a matter of style. If you’ve been around since they introduced DB2, you were probably taught a little differently than a recent computer science graduate. If you have a company standard, I strongly recommend you follow it. If you do not have a standard, generally speaking, there is no right or wrong answer when talking about the efficiency of these types of queries, and certainly no hard-and-fast rule. Volume and infrastructure will dictate a lot when it comes to performance, so your results may vary in your environment. Download the database and try it!

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Upgrading SSIS Custom Components for SQL Server 2012

Having finally got around to upgrading my custom components to SQL Server 2012, I thought I’d share some notes on the process. One of the goals was minimal duplication, so the same code files are used to build the 2008 and 2012 components, I just have a separate project file. The high level steps are listed below, followed by some more details. Create a 2012 copy of the project file Upgrade project, just open the new project file is VS2010 Change target framework to .NET 4.0 Set conditional compilation symbol for DENALI Change any conditional code, including assembly version and UI type name Edit project file to change referenced assemblies for 2012 Change target framework to .NET 4.0 Open the project properties. On the Applications page, change the Target framework to .NET Framework 4. Set conditional compilation symbol for DENALI Re-open the project properties. On the Build tab, first change the Configuration to All Configurations, then set a Conditional compilation symbol of DENALI. Change any conditional code, including assembly version and UI type name The value doesn’t have to be DENALI, it can actually be anything you like, that is just what I use. It is how I control sections of code that vary between versions. There were several API changes between 2005 and 2008, as well as interface name changes. Whilst we don’t have the same issues between 2008 and 2012, I still have some sections of code that do change such as the assembly attributes. #if DENALI [assembly: AssemblyDescription("Data Generator Source for SQL Server Integration Services 2012")] [assembly: AssemblyCopyright("Copyright © 2012 Konesans Ltd")] [assembly: AssemblyVersion("3.0.0.0")] #else [assembly: AssemblyDescription("Data Generator Source for SQL Server Integration Services 2008")] [assembly: AssemblyCopyright("Copyright © 2008 Konesans Ltd")] [assembly: AssemblyVersion("2.0.0.0")] #endif The Visual Studio editor automatically formats the code based on the current compilation symbols, hence in this case the 2008 code is grey to indicate it is disabled. As you can see in the previous example I have distinct assembly version attributes, ensuring I can run both 2008 and 2012 versions of my component side by side. For custom components with a user interface, be sure to update the UITypeName property of the DtsTask or DtsPipelineComponent attributes. As above I use the conditional compilation symbol to control the code. #if DENALI [DtsTask ( DisplayName = "File Watcher Task", Description = "File Watcher Task", IconResource = "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTask.ico", UITypeName = "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTaskUI,Konesans.Dts.Tasks.FileWatcherTask,Version=3.0.0.0,Culture=Neutral,PublicKeyToken=b2ab4a111192992b", TaskContact = "File Watcher Task; Konesans Ltd; Copyright © 2012 Konesans Ltd; http://www.konesans.com" )] #else [DtsTask ( DisplayName = "File Watcher Task", Description = "File Watcher Task", IconResource = "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTask.ico", UITypeName = "Konesans.Dts.Tasks.FileWatcherTask.FileWatcherTaskUI,Konesans.Dts.Tasks.FileWatcherTask,Version=2.0.0.0,Culture=Neutral,PublicKeyToken=b2ab4a111192992b", TaskContact = "File Watcher Task; Konesans Ltd; Copyright © 2004-2008 Konesans Ltd; http://www.konesans.com" )] #endif public sealed class FileWatcherTask: Task, IDTSComponentPersist, IDTSBreakpointSite, IDTSSuspend { // .. code goes on... } Shown below is another example I found that needed changing. I borrow one of the MS editors, and use it against a custom property, but need to ensure I reference the correct version of the MS controls assembly. This section of code is actually shared between the 2005, 2008 and 2012 versions of my component hence it has test for both DENALI and KATMAI symbols. #if DENALI const string multiLineUI = "Microsoft.DataTransformationServices.Controls.ModalMultilineStringEditor, Microsoft.DataTransformationServices.Controls, Version=11.0.00.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; #elif KATMAI const string multiLineUI = "Microsoft.DataTransformationServices.Controls.ModalMultilineStringEditor, Microsoft.DataTransformationServices.Controls, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; #else const string multiLineUI = "Microsoft.DataTransformationServices.Controls.ModalMultilineStringEditor, Microsoft.DataTransformationServices.Controls, Version=9.0.242.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; #endif // Create Match Expression parameter IDTSCustomPropertyCollection100 propertyCollection = outputColumn.CustomPropertyCollection; IDTSCustomProperty100 property = propertyCollection.New(); property = propertyCollection.New(); property.Name = MatchParams.Name; property.Description = MatchParams.Description; property.TypeConverter = typeof(MultilineStringConverter).AssemblyQualifiedName; property.UITypeEditor = multiLineUI; property.Value = MatchParams.DefaultValue; Edit project file to change referenced assemblies for 2012 We now need to edit the project file itself. Open the MyComponente2012.cproj in you favourite text editor, and then perform a couple of find and replaces as listed below: Find Replace Comment Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91 Change the assembly references version from SQL Server 2008 to SQL Server 2012. Microsoft SQL Server\100\ Microsoft SQL Server\110\ Change any assembly reference hint path locations from from SQL Server 2008 to SQL Server 2012. If you use any Build Events during development, such as copying the component assembly to the DTS folder, or calling GACUTIL to install it into the GAC, you can also change these now. An example of my new post-build event for a pipeline component is shown below, which uses the .NET 4.0 path for GACUTIL. It also uses the 110 folder location, instead of 100 for SQL Server 2008, but that was covered the the previous find and replace. "C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\NETFX 4.0 Tools\gacutil.exe" /if "$(TargetPath)" copy "$(TargetPath)" "%ProgramFiles%\Microsoft SQL Server\110\DTS\PipelineComponents" /Y

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Checkinstall failed with /root/rpmbuild has no source directory

- by leo

I am trying to use checkinstall to build a package from source code. However, when i run checkinstall , it ask : /root/rpmbuild has no source directory, please write the path to the rpm source directory tree. i am running on fedora 12 and system was installed through kickstart via repository of dvd of fc12. I was not aware of the rpm source directory during the installation. so how can i check whether rpm source has been installed or not. if not, how to make the rpm source directory so that i can please the checkinstall and build the package successfully. or can i bypass it? thanks a lot

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Source File not updating Destination Files in Excel

- by user127105

I have one source file that holds all my input costs. I then have 30 to 40 destination files (costing sheets) that use links to data in this source file for their various formulae. I was sure when I started this system that any changes I made to the source file, including the insertion of new rows and columns was updated automatically by the destination files, such that the formula always pulled the correct input costs. Now all of a sudden if my destination files are closed and I change the structure of the source file by adding rows - the destination files go haywire? They pick up changes to their linked cells, but don't pick up changes to the source sheet that have shifted their relative positions in the sheet. Do I really need to open all 40 destination files at the same time I alter the source file structure? Further info: all the destination files are protected, and I am working on DropBox.

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SQL -- How to combine three SELECT statements with very tricky requirements

- by Frederick

I have a SQL query with three SELECT statements. A picture of the data tables generated by these three select statements is located at www.britestudent.com/pub/1.png. Each of the three data tables have identical columns. I want to combine these three tables into one table such that: (1) All rows in top table (Table1) are always included. (2) Rows in the middle table (Table2) are included only when the values in column1 (UserName) and column4 (CourseName) do not match with any row from Table1. Both columns need to match for the row in Table2 to not be included. (3) Rows in the bottom table (Table3) are included only when the value in column4 (CourseName) is not already in any row of the results from combining Table1 and Table2. I have had success in implementing (1) and (2) with an SQL query like this: SELECT DISTINCT UserName AS UserName, MAX(AmountUsed) AS AmountUsed, MAX(AnsweredCorrectly) AS AnsweredCorrectly, CourseName, MAX(course_code) AS course_code, MAX(NoOfQuestionsInCourse) AS NoOfQuestionsInCourse, MAX(NoOfQuestionSetsInCourse) AS NoOfQuestionSetsInCourse FROM ( "SELECT statement 1" UNION "SELECT statement 2" ) dt_derivedTable_1 GROUP BY CourseName, UserName Where "SELECT statement 1" is the query that generates Table1 and "SELECT statement 2" is the query that generates Table2. A picture of the data table generated by this query is located at www.britestudent.com/pub/2.png. I can get away with using the MAX() function because values in the AmountUsed and AnsweredCorrectly columns in Table1 will always be larger than those in Table2 (and they are identical in the last three columns of both tables). What I fail at is implementing (3). Any suggestions on how to do this will be appreciated. It is tricky because the UserName values in Table3 are null, and because the CourseName values in the combined Table1 and Table2 results are not unique (but they are unique in Table3). After implementing (3), the final table should look like the table in picture 2.png with the addition of the last row from Table3 (the row with the CourseName value starting with "4. Klasse..." I have tried to implement (3) using another derived table using SELECT, MAX() and UNION, but I could not get it to work. Below is my full SQL query with the lines from this failed attempt to implement (3) commented out. Cheers, Frederick PS--I am new to this forum (and new to SQL as well), but I have had more of my previous problems answered by reading other people's posts on this forum than from reading any other forum or Web site. This forum is a great resources. -- SELECT DISTINCT MAX(UserName), MAX(AmountUsed) AS AmountUsed, MAX(AnsweredCorrectly) AS AnsweredCorrectly, CourseName, MAX(course_code) AS course_code, MAX(NoOfQuestionsInCourse) AS NoOfQuestionsInCourse, MAX(NoOfQuestionSetsInCourse) AS NoOfQuestionSetsInCourse -- FROM ( SELECT DISTINCT UserName AS UserName, MAX(AmountUsed) AS AmountUsed, MAX(AnsweredCorrectly) AS AnsweredCorrectly, CourseName, MAX(course_code) AS course_code, MAX(NoOfQuestionsInCourse) AS NoOfQuestionsInCourse, MAX(NoOfQuestionSetsInCourse) AS NoOfQuestionSetsInCourse FROM ( -- Table 1 - All UserAccount/Course combinations that have had quizzez. SELECT DISTINCT dbo.win_user.user_name AS UserName, cast(dbo.GetAmountUsed(dbo.session_header.win_user_id, dbo.course.course_id, dbo.course.no_of_questionsets_in_course) as nvarchar(10)) AS AmountUsed, Isnull(cast(dbo.GetAnswerCorrectly(dbo.session_header.win_user_id, dbo.course.course_id, dbo.question_set.no_of_questions) as nvarchar(10)),0) AS AnsweredCorrectly, dbo.course.course_name AS CourseName, dbo.course.course_code, dbo.course.no_of_questions_in_course AS NoOfQuestionsInCourse, dbo.course.no_of_questionsets_in_course AS NoOfQuestionSetsInCourse FROM dbo.session_detail INNER JOIN dbo.session_header ON dbo.session_detail.session_header_id = dbo.session_header.session_header_id INNER JOIN dbo.win_user ON dbo.session_header.win_user_id = dbo.win_user.win_user_id INNER JOIN dbo.win_user_course ON dbo.win_user_course.win_user_id = dbo.win_user.win_user_id INNER JOIN dbo.question_set ON dbo.session_header.question_set_id = dbo.question_set.question_set_id RIGHT OUTER JOIN dbo.course ON dbo.win_user_course.course_id = dbo.course.course_id WHERE (dbo.session_detail.no_of_attempts = 1 OR dbo.session_detail.no_of_attempts IS NULL) AND (dbo.session_detail.is_correct = 1 OR dbo.session_detail.is_correct IS NULL) AND (dbo.win_user_course.is_active = 'True') GROUP BY dbo.win_user.user_name, dbo.course.course_name, dbo.question_set.no_of_questions, dbo.course.no_of_questions_in_course, dbo.course.no_of_questionsets_in_course, dbo.session_header.win_user_id, dbo.course.course_id, dbo.course.course_code UNION ALL -- Table 2 - All UserAccount/Course combinations that do or do not have quizzes but where the Course is selected for quizzes for that User Account. SELECT dbo.win_user.user_name AS UserName, -1 AS AmountUsed, -1 AS AnsweredCorrectly, dbo.course.course_name AS CourseName, dbo.course.course_code, dbo.course.no_of_questions_in_course AS NoOfQuestionsInCourse, dbo.course.no_of_questionsets_in_course AS NoOfQuestionSetsInCourse FROM dbo.win_user_course INNER JOIN dbo.win_user ON dbo.win_user_course.win_user_id = dbo.win_user.win_user_id RIGHT OUTER JOIN dbo.course ON dbo.win_user_course.course_id = dbo.course.course_id WHERE (dbo.win_user_course.is_active = 'True') GROUP BY dbo.win_user.user_name, dbo.course.course_name, dbo.course.no_of_questions_in_course, dbo.course.no_of_questionsets_in_course, dbo.course.course_id, dbo.course.course_code ) dt_derivedTable_1 GROUP BY CourseName, UserName -- UNION ALL -- Table 3 - All Courses. -- SELECT DISTINCT null AS UserName, -- -2 AS AmountUsed, -- -2 AS AnsweredCorrectly, -- dbo.course.course_name AS CourseName, -- dbo.course.course_code, -- dbo.course.no_of_questions_in_course AS NoOfQuestionsInCourse, -- dbo.course.no_of_questionsets_in_course AS NoOfQuestionSetsInCourse -- FROM dbo.course -- WHERE is_active = 'True' -- ) dt_derivedTable_2 -- GROUP BY CourseName -- ORDER BY CourseName

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Unable to connect SQL Server instance from Visual Studio 2008 Version 9.0

- by salvationishere

I am getting the below error from VS on an 32-bit XP Professional server even though I set Tools-Options-Database Tools-Data Connections to "SIDEKICK", which is the name of my computer. In other words SIDEKICK should default to the full SQLSERVER. In other words, I want VS to use SQLSERVER instead of SQLSERVER EXPRESS. And I can clearly see my database both from VS in the Server Explorer and also in SSMS 2008. Furthermore, I can view the tables of this database in Server Explorer from VS. I do not get any build errors. And it looks like all of the naming is consistent in my web.config file. I am developing my website according to a Microsoft tutorial, so I should not be getting an error. Yet I get the following exception when I run this code below: CreateAccounts.aspx.cs file protected void CreateAccountButton_Click(object sender, EventArgs e) { MembershipCreateStatus createStatus; //This line below is where the exception occurs MembershipUser newUser = Membership.CreateUser(Username.Text, Password.Text, Email.Text, passwordQuestion, SecurityAnswer.Text, true, out createStatus); And here is what the exception looks like: System.Web.HttpException was unhandled by user code Message="Unable to connect to SQL Server database." Source="System.Web" ErrorCode=-2147467259 StackTrace: at System.Web.DataAccess.SqlConnectionHelper.CreateMdfFile(String fullFileName, String dataDir, String connectionString) at System.Web.DataAccess.SqlConnectionHelper.EnsureSqlExpressDBFile(String connectionString) at System.Web.DataAccess.SqlConnectionHelper.GetConnection(String connectionString, Boolean revertImpersonation) at System.Web.Security.SqlMembershipProvider.CreateUser(String username, String password, String email, String passwordQuestion, String passwordAnswer, Boolean isApproved, Object providerUserKey, MembershipCreateStatus& status) at System.Web.Security.Membership.CreateUser(String username, String password, String email, String passwordQuestion, String passwordAnswer, Boolean isApproved, Object providerUserKey, MembershipCreateStatus& status) at System.Web.Security.Membership.CreateUser(String username, String password, String email, String passwordQuestion, String passwordAnswer, Boolean isApproved, MembershipCreateStatus& status) at Membership_CreatingUserAccounts.CreateAccountButton_Click(Object sender, EventArgs e) in c:\Documents and Settings\Admin\My Documents\Visual Studio 2008\WebSites\WebSite2\Membership\CreatingUserAccounts.aspx.cs:line 24 at System.Web.UI.WebControls.Button.OnClick(EventArgs e) at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) InnerException: System.Web.HttpException Message="Unable to connect to SQL Server database." Source="System.Web" ErrorCode=-2147467259 StackTrace: at System.Web.Management.SqlServices.GetSqlConnection(String server, String user, String password, Boolean trusted, String connectionString) at System.Web.Management.SqlServices.SetupApplicationServices(String server, String user, String password, Boolean trusted, String connectionString, String database, String dbFileName, SqlFeatures features, Boolean install) at System.Web.Management.SqlServices.Install(String database, String dbFileName, String connectionString) at System.Web.DataAccess.SqlConnectionHelper.CreateMdfFile(String fullFileName, String dataDir, String connectionString) InnerException: System.Data.SqlClient.SqlException Message="The user instance login flag is not supported on this version of SQL Server. The connection will be closed." Source=".Net SqlClient Data Provider" ErrorCode=-2146232060 Class=14 LineNumber=65536 Number=18493 Procedure="" Server="." State=1 StackTrace: at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK) at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at System.Web.Management.SqlServices.GetSqlConnection(String server, String user, String password, Boolean trusted, String connectionString) InnerException: The web.config connection string looks like: <connectionStrings> <add name="SecurityTutorialsConnectionString" connectionString="data source=.;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|SecurityTutorialsDatabase3.mdf;User Instance=true" providerName="System.Data.SqlClient"/> </connectionStrings> <system.web> <membership defaultProvider="SecurityTutorialsSqlMembershipProvider"> <providers> <add name="SecurityTutorialsSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="SecurityTutorialsConnectionString" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="true" applicationName="SecurityTutorials" requiresUniqueEmail="true" passwordFormat="Hashed" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="7" minRequiredNonalphanumericCharacters="1" passwordAttemptWindow="10" passwordStrengthRegularExpression=""/> </providers> </membership>

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sql perfomance on new server

- by Rapunzo

My database is running on a pc (AMD Phenom x6, intel ssd disk, 8GB DDR3 RAM and windows 7 OS + sql server 2008 R2 sp3 ) and it started working hard, timeout problems and up to 30 seconds long queries after 200 mb of database And I also have an old server pc (IBM x-series 266: 72*3 15k rpm scsi discs with raid5, 4 gb ram and windows server 2003 + sql server 2008 R2 sp3 ) and same query start to give results in 100 seconds.. I tried query analyser tool for tuning my indexed. but not so much improvements. its a big dissapointment for me. because I thought even its an old server pc it should be more powerfull with 15k rpm discs with raid5. what should I do. do I need $10.000 new server to get a good performance for my sql server? cant I use that IBM server? Extra information: there is 50 sql users and its an ERP program. There is my query ALTER FUNCTION [dbo].[fnDispoTerbiye] ( ) RETURNS TABLE AS RETURN ( SELECT MD.dispoNo, SV.sevkNo, M1.musteriAdi AS musteri, SD.tipTurId, TT.tipTur, SD.tipNo, SD.desenNo, SD.varyantNo, SUM(T.topMetre) AS toplamSevkMetre, MD.dispoMetresi, DT.gelisMetresi, ISNULL(DT.fire, 0) AS fire, SV.sevkTarihi, DT.gelisTarihi, SP.mamulTermin, SD.miktar AS siparisMiktari, M.musteriAdi AS boyahane, MD.akisNotu AS islemler, --dbo.fnAkisIslemleri(MD.dispoNo) DT.partiNo, DT.iplikBoyaId, B.tanimAd AS BoyaTuru, MAX(HD.hamEn) AS hamEn, MAX(HD.hamGramaj) AS hamGramaj, TS.mamulEn, TS.mamulGramaj, DT.atkiCekmesi, DT.cozguCekmesi, DT.fiyat, DV.dovizCins, DT.dovizId, (SELECT CASE WHEN DT.dovizId = 2 THEN CAST(round(SUM(T .topMetre) * DT.fiyat * (SELECT TOP 1 satis FROM tblKur WHERE dovizId = 2 ORDER BY tarih DESC), 2) AS numeric(18, 2)) WHEN DT.dovizId = 3 THEN CAST(round(SUM(T .topMetre) * DT.fiyat * (SELECT TOP 1 satis FROM tblKur WHERE dovizId = 3 ORDER BY tarih DESC), 2) AS numeric(18, 2)) WHEN DT.dovizId = 1 THEN CAST(round(SUM(T .topMetre) * DT.fiyat * (SELECT TOP 1 satis FROM tblKur WHERE dovizId = 1 ORDER BY tarih DESC), 2) AS numeric(18, 2)) END AS Expr1) AS ToplamTLfiyat, DT.aciklama, MD.dispoNotu, SD.siparisId, SD.siparisDetayId, DT.sqlUserName, DT.kayitTarihi, O.orguAd, 'Çözgü=(' + (SELECT dbo.fnTipIplikler(SD.tipTurId, SD.tipNo, SD.desenNo, SD.varyantNo, 1) AS Expr1) + ')' + ' Atki=(' + (SELECT dbo.fnTipIplikler(SD.tipTurId, SD.tipNo, SD.desenNo, SD.varyantNo, 2) AS Expr1) + ')' AS iplikAciklama, DT.prosesOk, dbo.[fnYikamaTalimat](SP.siparisId) yikamaTalimati FROM tblDoviz AS DV WITH(NOLOCK) INNER JOIN tblDispoTerbiye AS DT WITH(NOLOCK) INNER JOIN tblTanimlar AS B WITH(NOLOCK) ON DT.iplikBoyaId = B.tanimId AND B.tanimTurId = 2 ON DV.id = DT.dovizId RIGHT OUTER JOIN tblMusteri AS M1 WITH(NOLOCK) INNER JOIN tblSiparisDetay AS SD WITH(NOLOCK) INNER JOIN tblDispo AS MD WITH(NOLOCK) ON SD.siparisDetayId = MD.siparisDetayId INNER JOIN tblTipTur AS TT WITH(NOLOCK) ON SD.tipTurId = TT.tipTurId INNER JOIN tblSiparis AS SP WITH(NOLOCK) ON SD.siparisId = SP.siparisId ON M1.musteriNo = SP.musteriNo INNER JOIN tblTip AS TP WITH(NOLOCK) ON SD.tipTurId = TP.tipTurId AND SD.tipNo = TP.tipNo AND SD.desenNo = TP.desen AND SD.varyantNo = TP.varyant INNER JOIN tblOrgu AS O WITH(NOLOCK) ON TP.orguId = O.orguId INNER JOIN tblMusteri AS M WITH(NOLOCK) INNER JOIN tblSevkiyat AS SV WITH(NOLOCK) ON M.musteriNo = SV.musteriNo INNER JOIN tblSevkDetay AS SVD WITH(NOLOCK) ON SV.sevkNo = SVD.sevkNo ON MD.mamulDispoHamSevkno = SV.sevkNo LEFT OUTER JOIN tblTop AS T WITH(NOLOCK) INNER JOIN tblDispo AS HD WITH(NOLOCK) ON T.dispoNo = HD.dispoNo AND T.dispoTuruId = HD.dispoTuruId ON SVD.dispoTuruId = T.dispoTuruId AND SVD.dispoNo = T.dispoNo AND SVD.topNo = T.topNo AND MD.siparisDetayId = HD.siparisDetayId ON DT.dispoTuruId = MD.dispoTuruId AND DT.dispoNo = MD.dispoNo LEFT OUTER JOIN tblDispoTerbiyeTest AS TS WITH(NOLOCK) ON DT.dispoTuruId = TS.dispoTuruId AND DT.dispoNo = TS.dispoNo --WHERE DT.gelisTarihi IS NULL -- OR DT.gelisTarihi > GETDATE()-30 GROUP BY MD.dispoNo, DT.partiNo, DT.iplikBoyaId, TS.mamulEn, TS.mamulGramaj, DT.gelisMetresi, DT.gelisTarihi, DT.atkiCekmesi, DT.cozguCekmesi, DT.fire, DT.fiyat, DT.aciklama, DT.sqlUserName, DT.kayitTarihi, SD.tipTurId, TT.tipTur, SD.tipNo, SD.desenNo, SD.varyantNo, SD.siparisId, SD.siparisDetayId, B.tanimAd, M.musteriAdi, M.musteriAdi, M1.musteriAdi, O.orguAd, TP.iplikAciklama, SD.miktar, MD.dispoNotu, SP.mamulTermin, DT.dovizId, DV.dovizCins, MD.dispoMetresi, MD.akisNotu, SV.sevkNo, SV.sevkTarihi, DT.prosesOk,SP.siparisId )

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Why Do I See the "In Recovery" Msg, and How Can I Prevent it?

- by John Hansen

The project I'm working on creates a local copy of the SQL Server database for each SVN branch you work on. We're running SQL Server 2008 Express with Advanced Services on our local machine to host it. When we create a new branch, the build script will create a new database with the ID of that branch, creates the schema objects, and copies over a selection of data from the production shadow server. After the database is created, it, or other databases on the local machine, will often go into "In Recovery" mode for several minutes. After several refreshes it comes up and is happy, but will occasionally go back into "In Recovery" mode. The database is created in simple recovery mode. The file names aren't specified, so it uses default paths for files. The size of the database after loading data is ~400 megs. It is running in SQL Server 2005 compatibility mode. The command that creates the database is: sqlcmd -S $(DBServer) -Q "IF NOT EXISTS (SELECT [name] FROM sysdatabases WHERE [name] = '$(DBName)') BEGIN CREATE DATABASE [$(DBName)]; print 'Created $(DBName)'; END" ...where $(DBName) and $(DBServer) are MSBuild parameters. I got a nice clean log file this morning. When I turned on my computer it starts all five databases. However, two of them show transactions being rolled forward and backwards. The it just keeps trying to start up all five of the databases. 2010-06-10 08:24:59.74 spid52 Starting up database 'ASPState'. 2010-06-10 08:24:59.82 spid52 Starting up database 'CommunityLibrary'. 2010-06-10 08:25:03.97 spid52 Starting up database 'DLG-R8441'. 2010-06-10 08:25:05.07 spid52 2 transactions rolled forward in database 'DLG-R8441' (6). This is an informational message only. No user action is required. 2010-06-10 08:25:05.14 spid52 0 transactions rolled back in database 'DLG-R8441' (6). This is an informational message only. No user action is required. 2010-06-10 08:25:05.14 spid52 Recovery is writing a checkpoint in database 'DLG-R8441' (6). This is an informational message only. No user action is required. 2010-06-10 08:25:11.23 spid52 Starting up database 'DLG-R8979'. 2010-06-10 08:25:12.31 spid36s Starting up database 'DLG-R8441'. 2010-06-10 08:25:13.17 spid52 2 transactions rolled forward in database 'DLG-R8979' (9). This is an informational message only. No user action is required. 2010-06-10 08:25:13.22 spid52 0 transactions rolled back in database 'DLG-R8979' (9). This is an informational message only. No user action is required. 2010-06-10 08:25:13.22 spid52 Recovery is writing a checkpoint in database 'DLG-R8979' (9). This is an informational message only. No user action is required. 2010-06-10 08:25:18.43 spid52 Starting up database 'Rls QA'. 2010-06-10 08:25:19.13 spid46s Starting up database 'DLG-R8979'. 2010-06-10 08:25:23.29 spid36s Starting up database 'DLG-R8441'. 2010-06-10 08:25:27.91 spid52 Starting up database 'ASPState'. 2010-06-10 08:25:29.80 spid41s Starting up database 'DLG-R8979'. 2010-06-10 08:25:31.22 spid52 Starting up database 'Rls QA'. In this case it kept trying to start the databases continuously until I shut down SQL Server at 08:48:19.72, 23 minutes later. Meanwhile, I actually am able to use the databases much of the time.

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License for Opensource project

- by asterisk

I am newbie in the open source community world. I am planning to develop a open source project, hosted on github. The project would be using other open source components like- NHibernate, FNH, Log4net, CommonLibrary, Autofac, Quartz.Net Scheduler etc etc My questions are: Would there be any restrictions on using above OSS components? for example: I plan to use MIT license, but Quartz.Net Scheduler uses Apache license, would there be any restrictions? How do I get a license for my own project? Do I need to register my project somewhere? What is the best practice to mention credits to the OSS compoenents used? Many thanks,

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How can I determine if there is an open source software for a specific purpose?

- by afsharm

Hi, We are going to write an entire new application for a reservation system. In this system experts specify their free time in elaborated calendar and users seek them through searched and finally reserve the expert and his time. We prefer to find an open source program like this and try to evolve it instead of creating it from scratch. In this manner our time is saved and that open source program will be completer too. We are a entire .NET (ASP.NET, C#, NHibernate) company. We have same problem to find open source applications for our new projects. Any help is highly appreciated.

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What signing method to use for public open-source projects?

- by Irchi

I'm publishing an open-source library on CodePlex, and want the dll files to have strong names so that they can be added to GAC. What's the best option for signing? Should I use SNK? If so, everyone have access to the key. I don't have a problem with everyone having access, but is it a good approach? Should I use PFX? If so, does it mean that other people downloading the source code are not able to build the solution? What I like to do is that I am the only one person to have access to the key, so that the signed assemblies also have a level of authenticity, but meanwhile don't prevent other developers to download, build, or change the source code for themselves, and be able to post changes for the main project.

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Where can I find a large body of Python3 source code?

- by Ira Baxter

I'm testing a Python parser. I have Python 2.6/2.7 firmly under control, and some good (large) code samples on which I've tested it. I'm interested in testing my Python3 variant. I've been to various Python open source web sites (e.g., http://pythonsource.com/), which list lots of packages, but they are pretty unclear as whether these are Python 2.x vs 3.x source files. The several samples that I downloaded all turned out to be Python 2.x. Where can I find a number of large Python 3 software source codes? I don't really want 1000 little separate Python3 files; I prefer big applications.

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Why do open source projects cling on 0.x versions for too long?

- by ssg

I see many open source projects insist on staying in 0.xxx version for a very long time despite that the product has been proven useful and very stable. Trac is one example. They even risked switching from 0.9 to 0.10 which might confuse a lot of users about which is more recent. I wonder if this is a cultural paradigm, an honor code in open source community or simply a strict interpretation of release cycle management? Would a person who releases first version as "1.0 beta" be banished from open source world, or more realistically appeal less number of contributors? For some projects it even looks like they will never switch to 1.0 ever but only approximating only half way each time, like Zeno's paradox.

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vb.net : is it possible to connect to sql server 2008 via odbc but not through vb.net code?

- by phill

I'm supporting an old vb.net program whose database it connected to was moved from SQL Server 2005 to SQL Server 2008. Is there a setting on SQL Server 2008 which will allow ODBC connections to access the database but not allow VB.NET to connect to it programmatically? the error i keep receiving in the app is: An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 – Could not open a connection to SQL Server) however I can connect to it when I create a system dsn to the sql server instance and through VS2005's Tools Connect to Database. Here is the code I'm using to connect: dim strC as string strC = "data source=bob; database=subscribers; user id=bobuser; password=passme" dim connection as New SqlClient.SqlConnection(strC) try connection.open() catch ex as Exception msgbox(ex.message) end try connection.Close()

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SQL Server 2005 to 2008 Bak file help please!

- by Brandon

I have a SQl Server 2005 database backup that I want to transfer to SQL Server 2008 on my server. I spent 3 days transferring the .bak file from my own machine to my server. I then tried to restore the bak file and I got an error. I then read online a completely different method for adding a SQL server 2005 Database to SQL server 2008 which was the detach and attach method which means I need to detach the database in SQL Server 2005 and then transfer the MDF file from it via ftp to my server and then attach it in SQL Server 2008. Well I already used a lot of bandwidth transferring the .bak file to my server. is there a way to convert my .bak file which is already on my server to an MDF file and attach it in SQL server 2008?

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How to implement copy protection of content in an open source application?

- by Lococo

I have an idea for an open source app -- the app would be free, but I would charge a small fee for data that a customer would order. For instance, let's say I'm writing a map application. I'd give the app away, make it open-source, but I would like to sell various maps to individual users. Is there a way to protect the data in such a way that makes it very difficult for someone to simply take the map they bought and distribute it to others? Is this feasible for an open source app?

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Howto get iframe linking to internal document source using javascript/jQuery?

- by Tom

Hi there, I have an iframe with id "appframe", the source is page.html and it's on the same server. I want to get the source of the page using jQuery. alert($("#appframe").contents().find("html").html()); returns <head></head><body></body> even though the document does not contain those tags, it only contains "Default page", so that is exactly what it should return. Any idea how to get the right source script of the whole document using jQuery? Eg. if the document would be "test" then that is exactly what it should return. Please note: I did ask this before a few weeks ago. Unfortunately, I got no solving answer. Because of my lower reputation (~85), I can not request a bounty... This doesn't make much sense to me. Anyway, it forced me to repost this question.

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download all RPMs from a metapackage

- by Joey BagODonuts

example of what im trying to do # yumdownloader net-snmp.x86_64 --source Enabling epel-source repository epel-source | 2.9 kB 00:00 No source RPM found for 1:net-snmp-5.3.2.2-17.el5_8.1.x86_64 No source RPM found for 1:net-snmp-5.3.2.2-17.el5.x86_64 Nothing to download How do you download all the RPM's inside a metapackage?

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SQLAuthority News SQL Server 2008 R2 Update for Developers Training Kit (March 2010 Update)

SQL Server 2008 R2 offers an impressive array of capabilities for developers that build upon key innovations introduced in SQL Server 2008. The SQL Server 2008 R2 Update for Developers Training Kit is ideal for developers who want to understand how to take advantage of the key improvements introduced in SQL [...]...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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Slides and Links from SQL Azure session at BizSpark Azure Day in London

- by Eric Nelson

A big thanks to all who attended my two sessions on SQL Azure yesterday (29th March 2010). As promised, my slides and links from the session. SQL Azure Overview for Bizspark day View more presentations from Eric Nelson. Related Links: UK Azure Online Community – join today. UK Windows Azure Site Start working with Windows Azure SQL Azure maximum database size rises from 10GB to 50GB in June TCO and ROI calculator for Windows Azure SQL Azure Migration Wizard

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SQL Azure news at TechEd 2010

More Azure news from TechEd US 2010. This time, its from the SQL Azure team: 50GB databases available on June 28th Support for Spatial Data Data Sync Service for SQL Azure Microsoft SQL Server Web Manager Access 2010 Support for SQL Azure Read at about it here var addthis_pub="guybarrette";...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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SQL Azure news at TechEd 2010

- by guybarrette

More Azure news from TechEd US 2010. This time, it’s from the SQL Azure team: 50GB databases available on June 28th Support for Spatial Data Data Sync Service for SQL Azure Microsoft SQL Server Web Manager Access 2010 Support for SQL Azure Read at about it here var addthis_pub="guybarrette";

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Entity Framework 4.0: Optimal and horrible SQL

- by DigiMortal

Lately I had Entity Framework 4.0 session where I introduced new features of Entity Framework. During session I found out with audience how Entity Framework 4.0 can generate optimized SQL. After session I also showed guys one horrible example about how awful SQL can be generated by Entity Framework. In this posting I will cover both examples. Optimal SQL Before going to code take a look at following model. There is class called Event and I will use this class in my query. Here is the LINQ To Entities query that uses small anonymous type. var query = from e in _context.Events select new { Id = e.Id, Title = e.Title }; Debug.WriteLine(((ObjectQuery)query).ToTraceString()); Running this code gives us the following SQL. SELECT [Extent1].[event_id] AS [event_id], [Extent1].[title] AS [title] FROM [dbo].[events] AS [Extent1] This is really small – no additional fields in SELECT clause. Nice, isn’t it? Horrible SQL Ayende Rahien blog shows us darker side of Entiry Framework 4.0 queries. You can find comparison betwenn NHibernate, LINQ To SQL and LINQ To Entities from posting What happens behind the scenes: NHibernate, Linq to SQL, Entity Framework scenario analysis. In this posting I will show you the resulting query and let you think how much better it can be done. Well, it is not something we want to see running in our servers. I hope that EF team improves generated SQL to acceptable level before Visual Studio 2010 is released. There is also morale of this example: you should always check out the queries that O/R-mapper generates. Behind the curtains it may silently generate queries that perform badly and in this case you need to optimize you data querying strategy. Conclusion Entity Framework 4.0 is new product with a lot of new features and it is clear that not everything is 100% super in its first release. But it still great step forward and I hope that on 12.04.2010 we have new promising O/R-mapper available to use in our projects. If you want to read more about Entity Framework 4.0 and Visual Studio 2010 then please feel free to follow this link to list of my Visual Studio 2010 and .NET Framework 4.0 postings.

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