mysql - Deleting duplicate rows from a table -

-

I have a table in my database that has duplicate records that I want to delete. I do not want to create a new table with specific entries for it. What I need is to remove duplicate entries from the existing table without any new table formation. Is there any way to do this? 

  id action L1_name L1_data L2_name L2_data L3_name L3_data L4_name L4_data L5_name L5_data L6_name L6_data L7_name L7_data L8_name L8_data L9_name L9_data L10_name L10_data L11_name L11_data L12_name L12_data L13_name L13_data L14_name L14_data L15_name is L15_data

All of these are my fields:
ID is unique to every line.
The L11_data is unique to the corresponding action field.
L11_data is going to be the name of the company while action industries have been named.

So in my data, I keep duplicate names for companies in my L1_data for their respective industries.

What do I want that companies should have unique names and other data in a specialized industry stored in action. I hope I have explained my problem in the way that you guys can understand.

Yes, there is a unique ID field, you can delete all records which are the same except for the ID , But there is no "minimum ID" for your group values.

Example query: 

  Remove from table that does not have table ID (SELECT MIN (ID) from table group by field 1, field 2, field 3)  
 Note: 
 
     
  •  I have chosen the name "table" and "id" as a representative name for free 
    •  
  •  List of fields It should be a slow query based on the number of fields and rows (though "field 1, field 2, ...") id 
    •  
  •  Do Mmid that option it will recover over 
    •  
 
 Edit: If you do not have a unique index, my recommendation is to add an auto-incremental unique index. Mainly because it is a good design, but it will also allow you to run the following question.

Comments

Post a Comment

Popular posts from this blog

c++ - Linux and clipboard -

-
After selecting the copies of the buffer in Linux, after the text, we can click and paste the button between the mouse. I think there is a special buffer for this, I want to use it. Programming Language: C ++ Your Library: Qt Thanks. There is just one more correct answer than Paul Dixon, which answers your needs: / P > QClipboard * clipboard = QApplication :: clipboard (); CastString Selected Text = Clipboard-> Text (QClipboard :: Selection);
Read more

Visual Studio 2005: How to speed up builds when a VSMDI is open? -

-
Using Visual Studio 2005, if I open the test in VSMFI and try to run the tests, then sometimes the projects are ready. However, they run very slow. CPU 99% waste and output window VS Shows things associated with compiling it. Is there any way to fix this? It does not make any sense. It is not necessary to upgrade that we are a viable alternative to those people who have to deal with the legacy code. Did you try to upgrade SP1? I do not know of any specific problem in this area, but this will be the first change I tried to do.
Read more

booting ubuntu from usb using virtualbox -

-
I am trying to install Ubuntu on a USB, the problem is that I do not want to repeat the boot once, I want to keep my windows, but I want to boot Ubuntu using the virtualbox and USB to the Ubuntu Want to use my hard drive, but how? The virtualbox will not recognize USB as a hard drive when installing an ISO In virtualbox, you have to create a virtual hard disk. Make a USB drive and tell the virtual box to install a virtual hard drive that you just created. EDIT: To answer some more questions: In the new Virtual Disk dialog, click the button next to the location field, click on the button Virtual Disk on Flash Drive To access, click the arrow next to Save in the Select File in the window next to Save In, and you can access your flash drive from there. I recommend setting the image to be allocated dynamically, because the size of your flash drive is not available disk space. I name the image, then select that image to install Ubuntu in the Verbill box. The virtualbox will never
Read more