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  • SQL SERVER – Merge Operations – Insert, Update, Delete in Single Execution

    - by pinaldave
    This blog post is written in response to T-SQL Tuesday hosted by Jorge Segarra (aka SQLChicken). I have been very active using these Merge operations in my development. However, I have found out from my consultancy work and friends that these amazing operations are not utilized by them most of the time. Here is my attempt to bring the necessity of using the Merge Operation to surface one more time. MERGE is a new feature that provides an efficient way to do multiple DML operations. In earlier versions of SQL Server, we had to write separate statements to INSERT, UPDATE, or DELETE data based on certain conditions; however, at present, by using the MERGE statement, we can include the logic of such data changes in one statement that even checks when the data is matched and then just update it, and similarly, when the data is unmatched, it is inserted. One of the most important advantages of MERGE statement is that the entire data are read and processed only once. In earlier versions, three different statements had to be written to process three different activities (INSERT, UPDATE or DELETE); however, by using MERGE statement, all the update activities can be done in one pass of database table. I have written about these Merge Operations earlier in my blog post over here SQL SERVER – 2008 – Introduction to Merge Statement – One Statement for INSERT, UPDATE, DELETE. I was asked by one of the readers that how do we know that this operator was doing everything in single pass and was not calling this Merge Operator multiple times. Let us run the same example which I have used earlier; I am listing the same here again for convenience. --Let’s create Student Details and StudentTotalMarks and inserted some records. USE tempdb GO CREATE TABLE StudentDetails ( StudentID INTEGER PRIMARY KEY, StudentName VARCHAR(15) ) GO INSERT INTO StudentDetails VALUES(1,'SMITH') INSERT INTO StudentDetails VALUES(2,'ALLEN') INSERT INTO StudentDetails VALUES(3,'JONES') INSERT INTO StudentDetails VALUES(4,'MARTIN') INSERT INTO StudentDetails VALUES(5,'JAMES') GO CREATE TABLE StudentTotalMarks ( StudentID INTEGER REFERENCES StudentDetails, StudentMarks INTEGER ) GO INSERT INTO StudentTotalMarks VALUES(1,230) INSERT INTO StudentTotalMarks VALUES(2,255) INSERT INTO StudentTotalMarks VALUES(3,200) GO -- Select from Table SELECT * FROM StudentDetails GO SELECT * FROM StudentTotalMarks GO -- Merge Statement MERGE StudentTotalMarks AS stm USING (SELECT StudentID,StudentName FROM StudentDetails) AS sd ON stm.StudentID = sd.StudentID WHEN MATCHED AND stm.StudentMarks > 250 THEN DELETE WHEN MATCHED THEN UPDATE SET stm.StudentMarks = stm.StudentMarks + 25 WHEN NOT MATCHED THEN INSERT(StudentID,StudentMarks) VALUES(sd.StudentID,25); GO -- Select from Table SELECT * FROM StudentDetails GO SELECT * FROM StudentTotalMarks GO -- Clean up DROP TABLE StudentDetails GO DROP TABLE StudentTotalMarks GO The Merge Join performs very well and the following result is obtained. Let us check the execution plan for the merge operator. You can click on following image to enlarge it. Let us evaluate the execution plan for the Table Merge Operator only. We can clearly see that the Number of Executions property suggests value 1. Which is quite clear that in a single PASS, the Merge Operation completes the operations of Insert, Update and Delete. I strongly suggest you all to use this operation, if possible, in your development. I have seen this operation implemented in many data warehousing applications. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Joins, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Merge

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  • SQL SERVER – Unable to DELETE Project in Data Quality Projects (DQS)

    - by pinaldave
    Here is the email which made me write this blog post. When I write a blog post I write keeping in mind that if the developer is not familiar with the concept he will attempt this on the development server. If due to any reason you attempt it on any other server than your personal server, developer should make sure to have complete confidence on his own expertise and understand the risk behind it.  Well, let us read the email which I received. I have modified it a bit to remove information related to organizational and individual. “I just read your blog post on Beginning DQS. I went ahead and followed every single screenshot and it worked fine. I was able to execute the DQS project successfully. However, the same blog post got me in trouble – a serious trouble. After first successful deployment I went ahead and created a few of my own knowledge base and projects. I played around a bit and then decided to get back to real work. Now we had deployed DQS on production server only, so experiment on production server. Now, when I got back to my work, I forgot to close all the windows. My manager found the window open and have seen my test projects. He has asked me to delete my experiments immediately and have said words which I cannot write to you. Here is the problem. I am not able to delete the project which I have created earlier. I am able to open it and play with it but the delete option is disabled and grayed out (see attached image). Now I believe there is nothing wrong with this project as it was just a test project. Would you please write to my manager that it is not harmful to leave that project there as it is? It is also not using any resources. I think he will believe you.” As I said this kind of email makes me uncomfortable. I do not want someone to execute anything on production server. I often write notes and disclaimer on my post when something is dangerous to execute on production server. However, if someone is not expert with SQL Server and attempts something new on production server, I think the major issue is here with the person (admin) who gave new developer permission to production server. This has to be carefully avoided. Here was my response to the individual. “I cannot write to your manager anything as he has not asked me anything. Honestly I believe he is correct in his behavior as you should have not executed anything on the production server without prior approval and testing on the development server. Any R&D must be done on local box or development box. I suggest you request your manager to prevent access to users who does not need access. If he is a good manager, he might have already implemented by now recent event. I also see your screenshot. Here is the issue: While you were playing with project, you might have closed the project half the way, without completing it. Due to the same reason it is locked. You can open and continue from the same place where you have left the project. If you do not need the project any more. Right click on it, click on unlock the project. This will enable the DELETE option and now you can delete the project. Next time, be safe out there. It may be dangerous to have admin access to production server when not needed.“ I have yet not heard from him but I believe he will take my words positively. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Data Quality Services, DQS

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  • When row estimation goes wrong

    - by Dave Ballantyne
    Whilst working at a client site, I hit upon one of those issues that you are not sure if that this is something entirely new or a bug or a gap in your knowledge. The client had a large query that needed optimizing.  The query itself looked pretty good, no udfs, UNION ALL were used rather than UNION, most of the predicates were sargable other than one or two minor ones.  There were a few extra joins that could be eradicated and having fixed up the query I then started to dive into the plan. I could see all manor of spills in the hash joins and the sort operations,  these are caused when SQL Server has not reserved enough memory and has to write to tempdb.  A VERY expensive operation that is generally avoidable.  These, however, are a symptom of a bad row estimation somewhere else, and when that bad estimation is combined with other estimation errors, chaos can ensue. Working my way back down the plan, I found the cause, and the more I thought about it the more i came convinced that the optimizer could be making a much more intelligent choice. First step is to reproduce and I was able to simplify the query down a single join between two tables, Product and ProductStatus,  from a business point of view, quite fundamental, find the status of particular products to show if ‘active’ ,’inactive’ or whatever. The query itself couldn’t be any simpler The estimated plan looked like this: Ignore the “!” warning which is a missing index, but notice that Products has 27,984 rows and the join outputs 14,000. The actual plan shows how bad that estimation of 14,000 is : So every row in Products has a corresponding row in ProductStatus.  This is unsurprising, in fact it is guaranteed,  there is a trusted FK relationship between the two columns.  There is no way that the actual output of the join can be different from the input. The optimizer is already partly aware of the foreign key meta data, and that can be seen in the simplifiction stage. If we drop the Description column from the query: the join to ProductStatus is optimized out. It serves no purpose to the query, there is no data required from the table and the optimizer knows that the FK will guarantee that a matching row will exist so it has been removed. Surely the same should be applied to the row estimations in the initial example, right ?  If you think so, please upvote this connect item. So what are our options in fixing this error ? Simply changing the join to a left join will cause the optimizer to think that we could allow the rows not to exist. or a subselect would also work However, this is a client site, Im not able to change each and every query where this join takes place but there is a more global switch that will fix this error,  TraceFlag 2301. This is described as, perhaps loosely, “Enable advanced decision support optimizations”. We can test this on the original query in isolation by using the “QueryTraceOn” option and lo and behold our estimated plan now has the ‘correct’ estimation. Many thanks goes to Paul White (b|t) for his help and keeping me sane through this

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  • Make Ant's delete task fail when a directory exists and is not deleted but not when it doesn't exist

    - by Tim Visher
    I have tho following clean function in my build script and I'd like to know how I can improve it. <target name="clean" description="Clean output directories."> <!-- Must not fail on error because it fails if directories don't exist. Is there really no better way to do this? --> <delete includeEmptyDirs="true" failonerror="false"> <fileset dir="${main.build.directory}" /> <fileset dir="dist" /> <fileset dir="${documentation.build.directory}" /> <fileset dir="/build-testing" /> </delete> </target> Specifically regarding my comment, I'm unhappy with the fact that I can't run this on a fresh box because the directory structure hasn't been set up yet by the other targets. We run the build in such a way that it entirely recreates the structures necessary for testing and deployment every time to avoid stale class files and such. With the way that delete currently is set up, a failure to delete a file does not fail the build and I'd like it to. I don't want it to fail the build if the file doesn't exist though. If it doesn't exist then what I'm asking it to do has already happened. Thoughts?

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  • How to insert and call by row and column into sqlite3 python, great tutorial problem.

    - by user291071
    Lets say i have a simple array of x rows and y columns with corresponding values, What is the best method to do 3 things? How to insert, update a value at a specific row column? How to select a value for each row and column, import sqlite3 con = sqlite3.connect('simple.db') c = con.cursor() c.execute('''create table simple (links text)''') con.commit() dic = {'x1':{'y1':1.0,'y2':0.0},'x2':{'y1':0.0,'y2':2.0,'y3':1.5},'x3':{'y2':2.0,'y3':1.5}} ucols = {} ## my current thoughts are collect all row values and all column values from dic and populate table row and columns accordingly how to call by row and column i havn't figured out yet ##populate rows in first column for row in dic: print row c.execute("""insert into simple ('links') values ('%s')"""%row) con.commit() ##unique columns for row in dic: print row for col in dic[row]: print col ucols[col]=dic[row][col] ##populate columns for col in ucols: print col c.execute("alter table simple add column '%s' 'float'" % col) con.commit() #functions needed ##insert values into sql by row x and column y?how to do this e.g. x1 and y2 should put in 0.0 ##I tried as follows didn't work for row in dic: for col in dic[row]: val =dic[row][col] c.execute("""update simple SET '%s' = '%f' WHERE 'links'='%s'"""%(col,val,row)) con.commit() ##update value at a specific row x and column y? ## select a value at a specific row x and column y?

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  • How to Implement Project Type "Copy", "Move", "Rename", and "Delete"

    - by Geertjan
    You've followed the NetBeans Project Type Tutorial and now you'd like to let the user copy, move, rename, and delete the projects conforming to your project type. When they right-click a project, they should see the relevant menu items and those menu items should provide dialogs for user interaction, followed by event handling code to deal with the current operation. Right now, at the end of the tutorial, the "Copy" and "Delete" menu items are present but disabled, while the "Move" and "Rename" menu items are absent: The NetBeans Project API provides a built-in mechanism out of the box that you can leverage for project-level "Copy", "Move", "Rename", and "Delete" actions. All the functionality is there for you to use, while all that you need to do is a bit of enablement and configuration, which is described below. To get started, read the following from the NetBeans Project API: http://bits.netbeans.org/dev/javadoc/org-netbeans-modules-projectapi/org/netbeans/spi/project/ActionProvider.html http://bits.netbeans.org/dev/javadoc/org-netbeans-modules-projectapi/org/netbeans/spi/project/CopyOperationImplementation.html http://bits.netbeans.org/dev/javadoc/org-netbeans-modules-projectapi/org/netbeans/spi/project/MoveOrRenameOperationImplementation.html http://bits.netbeans.org/dev/javadoc/org-netbeans-modules-projectapi/org/netbeans/spi/project/DeleteOperationImplementation.html Now, let's do some work. For each of the menu items we're interested in, we need to do the following: Provide enablement and invocation handling in an ActionProvider implementation. Provide appropriate OperationImplementation classes. Add the new classes to the Project Lookup. Make the Actions visible on the Project Node. Run the application and verify the Actions work as you'd like. Here we go: Create an ActionProvider. Here you specify the Actions that should be supported, the conditions under which they should be enabled, and what should happen when they're invoked, using lots of default code that lets you reuse the functionality provided by the NetBeans Project API: class CustomerActionProvider implements ActionProvider { @Override public String[] getSupportedActions() { return new String[]{ ActionProvider.COMMAND_RENAME, ActionProvider.COMMAND_MOVE, ActionProvider.COMMAND_COPY, ActionProvider.COMMAND_DELETE }; } @Override public void invokeAction(String string, Lookup lkp) throws IllegalArgumentException { if (string.equalsIgnoreCase(ActionProvider.COMMAND_RENAME)) { DefaultProjectOperations.performDefaultRenameOperation( CustomerProject.this, ""); } if (string.equalsIgnoreCase(ActionProvider.COMMAND_MOVE)) { DefaultProjectOperations.performDefaultMoveOperation( CustomerProject.this); } if (string.equalsIgnoreCase(ActionProvider.COMMAND_COPY)) { DefaultProjectOperations.performDefaultCopyOperation( CustomerProject.this); } if (string.equalsIgnoreCase(ActionProvider.COMMAND_DELETE)) { DefaultProjectOperations.performDefaultDeleteOperation( CustomerProject.this); } } @Override public boolean isActionEnabled(String command, Lookup lookup) throws IllegalArgumentException { if ((command.equals(ActionProvider.COMMAND_RENAME))) { return true; } else if ((command.equals(ActionProvider.COMMAND_MOVE))) { return true; } else if ((command.equals(ActionProvider.COMMAND_COPY))) { return true; } else if ((command.equals(ActionProvider.COMMAND_DELETE))) { return true; } return false; } } Importantly, to round off this step, add "new CustomerActionProvider()" to the "getLookup" method of the project. If you were to run the application right now, all the Actions we're interested in would be enabled (if they are visible, as described in step 4 below) but when you invoke any of them you'd get an error message because each of the DefaultProjectOperations above looks in the Lookup of the Project for the presence of an implementation of a class for handling the operation. That's what we're going to do in the next step. Provide Implementations of Project Operations. For each of our operations, the NetBeans Project API lets you implement classes to handle the operation. The dialogs for interacting with the project are provided by the NetBeans project system, but what happens with the folders and files during the operation can be influenced via the operations. Below are the simplest possible implementations, i.e., here we assume we want nothing special to happen. Each of the below needs to be in the Lookup of the Project in order for the operation invocation to succeed. private final class CustomerProjectMoveOrRenameOperation implements MoveOrRenameOperationImplementation { @Override public List<FileObject> getMetadataFiles() { return new ArrayList<FileObject>(); } @Override public List<FileObject> getDataFiles() { return new ArrayList<FileObject>(); } @Override public void notifyRenaming() throws IOException { } @Override public void notifyRenamed(String nueName) throws IOException { } @Override public void notifyMoving() throws IOException { } @Override public void notifyMoved(Project original, File originalPath, String nueName) throws IOException { } } private final class CustomerProjectCopyOperation implements CopyOperationImplementation { @Override public List<FileObject> getMetadataFiles() { return new ArrayList<FileObject>(); } @Override public List<FileObject> getDataFiles() { return new ArrayList<FileObject>(); } @Override public void notifyCopying() throws IOException { } @Override public void notifyCopied(Project prjct, File file, String string) throws IOException { } } private final class CustomerProjectDeleteOperation implements DeleteOperationImplementation { @Override public List<FileObject> getMetadataFiles() { return new ArrayList<FileObject>(); } @Override public List<FileObject> getDataFiles() { return new ArrayList<FileObject>(); } @Override public void notifyDeleting() throws IOException { } @Override public void notifyDeleted() throws IOException { } } Also make sure to put the above methods into the Project Lookup. Check the Lookup of the Project. The "getLookup()" method of the project should now include the classes you created above, as shown in bold below: @Override public Lookup getLookup() { if (lkp == null) { lkp = Lookups.fixed(new Object[]{ this, new Info(), new CustomerProjectLogicalView(this), new CustomerCustomizerProvider(this), new CustomerActionProvider(), new CustomerProjectMoveOrRenameOperation(), new CustomerProjectCopyOperation(), new CustomerProjectDeleteOperation(), new ReportsSubprojectProvider(this), }); } return lkp; } Make Actions Visible on the Project Node. The NetBeans Project API gives you a number of CommonProjectActions, including for the actions we're dealing with. Make sure the items in bold below are in the "getActions" method of the project node: @Override public Action[] getActions(boolean arg0) { return new Action[]{ CommonProjectActions.newFileAction(), CommonProjectActions.copyProjectAction(), CommonProjectActions.moveProjectAction(), CommonProjectActions.renameProjectAction(), CommonProjectActions.deleteProjectAction(), CommonProjectActions.customizeProjectAction(), CommonProjectActions.closeProjectAction() }; } Run the Application. When you run the application, you should see this: Let's now try out the various actions: Copy. When you invoke the Copy action, you'll see the dialog below. Provide a new project name and location and then the copy action is performed when the Copy button is clicked below: The message you see above, in red, might not be relevant to your project type. When you right-click the application and choose Branding, you can find the string in the Resource Bundles tab, as shown below: However, note that the message will be shown in red, no matter what the text is, hence you can really only put something like a warning message there. If you have no text at all, it will also look odd.If the project has subprojects, the copy operation will not automatically copy the subprojects. Take a look here and here for similar more complex scenarios. Move. When you invoke the Move action, the dialog below is shown: Rename. The Rename Project dialog below is shown when you invoke the Rename action: I tried it and both the display name and the folder on disk are changed. Delete. When you invoke the Delete action, you'll see this dialog: The checkbox is not checkable, in the default scenario, and when the dialog above is confirmed, the project is simply closed, i.e., the node hierarchy is removed from the application. However, if you truly want to let the user delete the project on disk, pass the Project to the DeleteOperationImplementation and then add the children of the Project you want to delete to the getDataFiles method: private final class CustomerProjectDeleteOperation implements DeleteOperationImplementation { private final CustomerProject project; private CustomerProjectDeleteOperation(CustomerProject project) { this.project = project; } @Override public List<FileObject> getDataFiles() { List<FileObject> files = new ArrayList<FileObject>(); FileObject[] projectChildren = project.getProjectDirectory().getChildren(); for (FileObject fileObject : projectChildren) { addFile(project.getProjectDirectory(), fileObject.getNameExt(), files); } return files; } private void addFile(FileObject projectDirectory, String fileName, List<FileObject> result) { FileObject file = projectDirectory.getFileObject(fileName); if (file != null) { result.add(file); } } @Override public List<FileObject> getMetadataFiles() { return new ArrayList<FileObject>(); } @Override public void notifyDeleting() throws IOException { } @Override public void notifyDeleted() throws IOException { } } Now the user will be able to check the checkbox, causing the method above to be called in the DeleteOperationImplementation: Hope this answers some questions or at least gets the discussion started. Before asking questions about this topic, please take the steps above and only then attempt to apply them to your own scenario. Useful implementations to look at: http://kickjava.com/src/org/netbeans/modules/j2ee/clientproject/AppClientProjectOperations.java.htm https://kenai.com/projects/nbandroid/sources/mercurial/content/project/src/org/netbeans/modules/android/project/AndroidProjectOperations.java

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  • Mystery undeletable file

    - by Hugh Allen
    I can't delete C:\Config.Msi\75ce84f.rbf. it's not readonly, system or hidden it's not in use by another process (according to Process Explorer) the NT security permissions aren't the problem either - I am the owner and have Full Control ; as a double-check, the Effective Permissions tab shows that I have permission to delete. Yet trying to delete the file gives "Access is Denied" from both Explorer and cmd. I can however rename it or move it to another folder on the same drive. I can also read it and Virustotal says it's clean which is what I would expect (it's just a Windows Installer temp file - a copy of some DLL I think). The relevant line from Process Monitor is: 6:52:14.3726983 PM 112 Explorer.EXE SetDispositionInformationFile C:\Config.Msi\75ce84f.rbf CANNOT DELETE Delete: True Write 1232 Background: I'm using XP SP2. I recently repaired my Adobe Reader installation to make it the default browser plugin again instead of Foxit. (there seems to be no UI to do it otherwise?) So the installer did its thing and then asked to reboot. As is my habit when rebooting is inconvenient I declined the offer and ran pendmoves to find out what files the installer had scheduled to move / delete. It wanted to delete two files with .rbf extension (rollback files) located in C:\Config.msi\. (this applies to both even though I've been speaking about one). So I tried to delete them manually and couldn't. Does anyone have any ideas what could be preventing deletion? (and I don't think it's malware even though I'm not running AV at the moment)

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  • Thunderbird does not delete messages from the POP server

    - by Max888
    Thunderbird does not delete messages from the POP server. I am a Yahoo Plus user and I can download messages from the inbox in Thunderbird from the Yahoo POP3 server. However, I want to delete read messages directly on the email client rather than go to Yahoo mail. When I do this, emails are still on the server In accounts setting, I have the following options ticked: -Automatically download new messages -Leave messages on server, Until I delete them Thanks for any guidance Update: Thanks for the replies so far. Some clarification: I do want to keep some messages on Yahoo for filling them in my online folders, hence the reason I do not download ALL my messages to Tbird and delete server message automatically **Update 2: Cracked it!! OK, boys and girls, here is the way to do it. Go to Options- Advanced - Config Editor find the Name 'mail . pop3 . deleteFromServerOnMove' Set it to True True: Delete the copy of the message on the POP3 server if you move or delete the message. False(default): Only delete the copy of the message on the POP3 server if you delete the message. That's it, restart Thunderbird. You need to press 'Get Mail' everytime you want to sync with the email server, in order for you to make sure messages in the application is in sync with the email server.**

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  • How do I automatically delete an Excel file after creating it on a server and returning it to the us

    - by David A Gibson
    Hello, I am creating an Excel file on a web server, using OleDb to connect the the physical (well as physical as it can be) file and appending records. I am then returning a FilePathResult to the user via MVC, and would like to delete the physical file afterwards due to data protection concerns over the appended records. I have tried using a File.Delete in a Finally clause but I get a File Not Found error which must mean the file has gone when MVC is trying to send the file to the user. I thought about creating the File as a MemoryStream but I think OleDb needs a physical file to connect to so this isn't an option. Any suggestions on how to delete the file after returning it in one operation? Thanks

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  • How would I use for_each to delete every value in an STL map?

    - by stusmith
    Suppose I have a STL map where the values are pointers, and I want to delete them all. How would I represent the following code, but making use of std::for_each? I'm happy for solutions to use Boost. for( stdext::hash_map<int, Foo *>::iterator ir = myMap.begin(); ir != myMap.end(); ++ir ) { delete ir->second; // delete all the (Foo *) values. } (I've found Boost's checked_delete, but I'm not sure how to apply that to the pair<int, Foo *> that the iterator represents). (Also, for the purposes of this question, ignore the fact that storing raw pointers that need deleting in an STL container isn't very sensible).

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  • How to retain a row which is foreign key in another table and remove other duplicate rows?

    - by Mithril
    I have two table: A: id code 1 A1 2 A1 3 B1 4 B1 5 C1 6 C1 ===================== B: id Aid 1 1 2 4 (B doesn't contain the Aid which link to code C1) Let me explain the overall flow: I want to make each row in table A have different code(by delete duplicate),and I want to retain the Aid which I can find in table B.If Aid which not be saved in table B,I retain the id bigger one. so I can not just do something as below: DELETE FROM A WHERE id NOT IN (SELECT MAX(id) FROM A GROUP BY code, ) I can get each duplicate_code_groups by below sql statement: SELECT code FROM A GROUP BY code HAVING COUNT(*) > 1 Is there some code in sql like for (var ids in duplicate_code_groups){ for (var id in ids) { if (id in B){ return id } } return max(ids) } and put the return id into a idtable?? I just don't know how to write such code in sql. then I can do DELETE FROM A WHERE id NOT IN idtable

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  • SQL SERVER – ColumnStore Index – Batch Mode vs Row Mode

    - by pinaldave
    What do you do when you are in a hurry and hear someone say things which you do not agree or is wrong? Well, let me tell you what I do or what I recently did. I was walking by and heard someone mentioning “Columnstore Index are really great as they are using Batch Mode which makes them seriously fast.” While I was passing by and I heard this statement my first reaction was I thought Columnstore Index can use both – Batch Mode and Row Mode. I stopped by even though I was in a hurry and asked the person if he meant that Columnstore indexes are seriously fast because they use Batch Mode all the time or Batch Mode is one of the reasons for Columnstore Index to be faster. He responded that Columnstore Indexes can run only in Batch Mode. However, I do not like to confront anybody without hearing their complete story. Honestly, I like to do information sharing and avoid confronting as much as possible. There are always ways to communicate the same positively. Well, this is what I did, I quickly pull up my earlier article on Columnstore Index and copied the script to SQL Server Management Studio. I created two versions of the script. 1) Very Large Table 2) Reasonably Small Table. I a query which uses columnstore index on both of the versions. I found very interesting result of the my tests. I saved my tests and sent it to the person who mentioned about that Columnstore Indexes are using Batch Mode only. He immediately acknowledged that indeed he was incorrect in saying that Columnstore Index uses only Batch Mode. What really caught my attention is that he also thanked me for sending him detail email instead of just having argument where he and I both were standing in the corridor and neither have no way to prove any theory. Here is the screenshots of the both the scenarios. 1) Columnstore Index using Batch Mode 2) Columnstore Index using Row Mode Here is the logic behind when Columnstore Index uses Batch Mode and when it uses Row Mode. A batch typically represents about 1000 rows of data. Batch mode processing also uses algorithms that are optimized for the multicore CPUs and increased memory throughput.  Batch mode processing spreads metadata access costs and overhead over all the rows in a batch.  Batch mode processing operates on compressed data when possible leading superior performance. Here is one last point – Columnstore Index can use Batch Mode or Row Mode but Batch Mode processing is only available in Columnstore Index. I hope this statement truly sums up the whole concept. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Index, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQLAuthority News – Keeping Your Ducks in a Row

    - by pinaldave
    Last year during my visit to SQLAuthority News – SQL PASS Summit, Seattle 2009 – Day 2 I have received ducks from the event. Well during the same event I had learned from Jonathan Kehayias the saying of ‘Keeping Your Ducks in a Row‘. The most popular theory suggests that “ducks in a row” came [...]

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  • PL/SQL to delete invalid data from token Strings

    - by Jie Chen
    Previous article describes how to delete the duplicated values from token string in bulk mode. This one extends it and shows the way to delete invalid data. Scenario Support we have page_two and manufacturers tables in database and the table DDL is: SQL> desc page_two; Name NULL? TYPE ----------------------------------------- -------- ------------------------ MULTILIST04 VARCHAR2(765) SQL> SQL> desc manufacturers; Name NULL? TYPE ----------------------------------------- -------- ------ ID NOT NULL NUMBER NAME VARCHAR In table page_two, column multilist04 stores a token string splitted with common. Each token represent a valid ID in manufacturers table. My expectation is to delete invalid token strings from page_two.multilist04, which have no mapping id in manufacturers.id. For example in below SQL result: ,6295728,33,6295729,6295730,6295731,22, , value 33 and 22 are invalid data because there is no ID equals to 33 or 22 in manufacturers table. So I need to delete 33 and 22. SQL> col rowid format a20; SQL> col multilist04 format a50; SQL> select rowid, multilist04 from page_two; ROWID MULTILIST04 -------------------- -------------------------------------------------- AAB+UrADfAAAAhUAAI ,6295728,6295729,6295730,6295731, AAB+UrADfAAAAhUAAJ ,1111,6295728,6295729,6295730,6295731, AAB+UrADfAAAAhUAAK ,6295728,111,6295729,6295730,6295731, AAB+UrADfAAAAhUAAL ,6295728,6295729,6295730,6295731,22, AAB+UrADfAAAAhUAAM ,6295728,33,6295729,6295730,6295731,22, SQL> select id, encode_name from manufacturers where id in (1111,11,22,33); No rows selected SQL> Solution As there is no existing SPLIT function or related in PL/SQL, I should program it by myself. I code Split intermediate function which is used to get the token value between current splitter and next splitter. Next program is main entry point, it get each column value from page_two.multilist04, process each row based on cursor. When it get each multilist04 value, it uses above Split function to get each token string stored to singValue variant, then check if it exists in manufacturers.id. If not found, set fixFlag to 1, pending to be deleted.

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  • User management system and DELETE action - usability

    - by šljaker
    I'm working on User Management System in ASP.NET MVC3. Administrator/Editor can search, insert, update and delete other users from the system. What should I do when admin/editor clicks on Delete user link? Should I redirect him to new yes/no confirmation page or display some jquery popup window? Should I then redirect him to the home page and display message 'The user has been successfully deleted from the system', or simple redirection should be just fine?

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  • Stairway to T-SQL DML Level 11: How to Delete Rows from a Table

    You may have data in a database that was inserted into a table by mistake, or you may have data in your tables that is no longer of value. In either case, when you have unwanted data in a table you need a way to remove it. The DELETE statement can be used to eliminate data in a table that is no longer needed. In this article you will see the different ways to use the DELETE statement to identify and remove unwanted data from your SQL Server tables.

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  • Delete action on a user management system [migrated]

    - by šljaker
    I'm working on User Management System in ASP.NET MVC3. Administrator/Editor can search, insert, update and delete other users from the system. What should I do when admin/editor clicks on Delete user link? Should I redirect him to new yes/no confirmation page or display some jquery popup window? Should I then redirect him to the home page and display message The user has been successfully deleted from the system, or simple redirection should be just fine?

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  • Row Count Plus Transformation

    As the name suggests we have taken the current Row Count Transform that is provided by Microsoft in the Integration Services toolbox and we have recreated the functionality and extended upon it. There are two things about the current version that we thought could do with cleaning up Lack of a custom UI You have to type the variable name yourself In the Row Count Plus Transformation we solve these issues for you.

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  • Problem with deleting table rows using ctrl+a for row selection

    - by Frank Nimphius
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The following code is commonly shown and documented for how to access the row key of selected table rows in an ADF Faces table configured for multi row selection. public void onRemoveSelectedTableRows(ActionEvent actionEvent) {    RichTable richTable = … get access to your table instance …    CollectionModel cm =(CollectionModel)richTable.getValue();    RowKeySet rowKeySet = (RowKeySet)richTable.getSelectedRowKeys();             for (Object key : rowKeySet) {       richTable.setRowKey(key);       JUCtrlHierNodeBinding rowData = (JUCtrlHierNodeBinding)cm.getRowData();       // do something with rowData e.g.update, print, copy   }    //optional, if you changed data, refresh the table         AdfFacesContext adfFacesContext = AdfFacesContext.getCurrentInstance(); adfFacesContext.addPartialTarget(richTable);   return null; } The code shown above works for 99.5 % of all use cases that deal with multi row selection enabled ADF Faces tables, except for when users use the ctrl+a key to mark all rows for delete. Just to make sure I am clear: if you use ctrl+a to mark rows to perform any other operation on them – like bulk updating all rows for a specific attribute – then this works with the code shown above. Even for bulk row delete, any other mean of row selection (shift+click and multiple ctrl+click) works like a charm and the rows are deleted. So apparently it is the use of ctrl+a that causes the problem when deleting multiple rows of an ADF Faces table. To implement code that works for all table selection use cases, including the one to delete all table rows in one go, you use the code shown below. public void onRemoveSelectedTableRows(ActionEvent actionEvent) {   RichTable richTable = … get access to your table instance …   CollectionModel cm = (CollectionModel)richTable.getValue();   RowKeySet rowKeySet = (RowKeySet)richTable.getSelectedRowKeys();   Object[] rowKeySetArray = rowKeySet.toArray();      for (Object key : rowKeySetArray){               richTable.setRowKey(key);     JUCtrlHierNodeBinding rowData = (JUCtrlHierNodeBinding)cm.getRowData();                              rowData.getRow().remove();   }   AdfFacesContext adfFacesContext = AdfFacesContext.getCurrentInstance();          adfFacesContext.addPartialTarget(richTable); }

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  • How to use HTTP method DELETE on Google App Engine?

    - by Jader Dias
    I can use this verb in the Python Windows SDK. But not in production. Why? What am I doing wrong? The error message includes (only seen via firebug or fiddler) Malformed request or something like that My code looks like: from google.appengine.ext import db from google.appengine.ext import webapp class Handler(webapp.RequestHandler): def delete(self): key = self.request.get('key') item = db.get(key) item.delete() self.response.out.write(key)

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