Find and remove duplicate rows by two columns

Question

I read all the relevant duplicated questions/answers and I found this to be the most relevant answer:

INSERT IGNORE INTO temp(MAILING_ID,REPORT_ID) 
SELECT DISTI         


        

Answer 1

NOTE: This solution is an alternative & old school solution.

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If you couldn't achieve what you wanted, then you can try my "oldschool" method:

First, run this query to get the duplicate records:

select   column1,
         column2,
         count(*)
from     table
group by column1,
         column2
having   count(*) > 1
order by count(*) desc

After that, select those results and paste them into the notepad++:

Now by using the find and replace specialty of the notepad++ replace them with; first "delete" then "insert" queries like this (from now on, for security reasons, my values will be AAAA).

Special Note: Please make another new line for the end of the last line of your data inside notepad++ because regex matched the '\r\n' at the end of the each line:

Find what regex: \D*(\d+)\D*(\d+)\D*\r\n

Replace with string: delete from table where column1 = $1 and column2 = $2; insert into table set column1 = $1, column2 = $2;\r\n

Now finally, paste those queries to your MySQL Workbench's query console and execute. You will see only one occurrences of each duplicate record.

This answer is for a relation table constructed of just two columns without ID. I think you can apply it to your situation.