Finding duplicate values in MySQL

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执笔经年
执笔经年 2020-11-22 04:04

I have a table with a varchar column, and I would like to find all the records that have duplicate values in this column. What is the best query I can use to find the duplic

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  •  别那么骄傲
    2020-11-22 04:40

    I am not seeing any JOIN approaches, which have many uses in terms of duplicates.

    This approach gives you actual doubled results.

    SELECT t1.* FROM my_table as t1 
    LEFT JOIN my_table as t2 
    ON t1.name=t2.name and t1.id!=t2.id 
    WHERE t2.id IS NOT NULL 
    ORDER BY t1.name
    

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