Skip to main content

How to delete duplicate row from table sql

If we want to delete the duplicate row from a table we can perform it by sq l. Consider the following SQ L query


 delete from PATIENT_INFO   
 where MrNo in (select MrNo  
         from PATIENT_INFO group by MrNo  
         having (count(PatientId))>1) and   
         PatientId not in (select min(PatientId)  
              from PATIENT_INFO   
              group by MrNo  
              having (count(PatientId))>1)  

Here PATIENT_INFO    is Table Name. and PatientId  is the primary key of the table. and we want to delete the duplicate MrNo  .

Comments

Popular posts from this blog

The calling thread must be STA, because many UI components require this.

Using Thread: // Create a thread Thread newWindowThread = new Thread(new ThreadStart(() => { // You can use your code // Create and show the Window FaxImageLoad obj = new FaxImageLoad(destination); obj.Show(); // Start the Dispatcher Processing System.Windows.Threading.Dispatcher.Run(); })); // Set the apartment state newWindowThread.SetApartmentState(ApartmentState.STA); // Make the thread a background thread newWindowThread.IsBackground = true; // Start the thread newWindowThread.Start(); Using Task and Thread: // Creating Task Pool, Each task will work asyn and as an indivisual thread component Task[] tasks = new Task[3]; // Control drug data disc UI load optimize tasks[0] = Task.Run(() => { //This will handle the ui thread :The calling thread must be STA, because many U...

WPF Crystal Report Viewer Using SAP

There is no doubt that we fall a great problem that the VS2010 is not intregated crystal report. Initially it seems to be a big problem. Hare is some step for SAP crystal report that we can use in our WPF application. 1.Download  Crystal report from this Link: http://scn.sap.com/docs/DOC-7824 2 . Remove Crystal report if any exist. 3. Close your VS-2010 and install the new downloaded CRforVS_13_0 . 4. Take a new WPF project   5. Right click on the project click on Properties 6. Change the target framework .NET Framework 4 Client Profile to  .NET Framework 4. 7. Click on main window then click on Toolbox.  Right Click on the General Tab then click on Choose Item. 8. It will appear this window click on WPF Component. 9.  Select CrystalReportsViewer  click on ok   Button. 10. Now you will see the report viewer control. 11. Your Crystal Report Environment is ready. Now we will a...

SQL Query Execution time of you in SQL Management Studio

You can check the Execution time of you SQL Query in SQL Management Studio. like this It is very simple that you just put your SQL Query in to the Estimated time execution query DECLARE @StartTime datetime DECLARE @EndTime datetime SELECT @StartTime=GETDATE() -- Write Your Query SELECT @EndTime=GETDATE() --This will return execution time of your query SELECT DATEDIFF(NS,@StartTime,@EndTime) AS [Duration in millisecs]