How do I delete duplicate data in MySQL in bulk?

1 year ago
Olivia Parker
1 minute

To bulk delete duplicate data in MySQL, you can follow these steps:

  1. Firstly, you need to identify the column containing the duplicate data that you want to remove. Suppose you have a table named table_name with a column named column_name, and you want to remove the duplicate data in the column_name column.
  2. Use the following query to find duplicate data:
SELECT column_name, COUNT(*) AS count
FROM table_name
GROUP BY column_name
HAVING COUNT(*) > 1;
  1. Based on the results of the above query, you can identify the duplicate data to be deleted. Then, use the following query to remove the duplicate data:
DELETE t1
FROM table_name t1
INNER JOIN table_name t2
WHERE t1.id > t2.id
AND t1.column_name = t2.column_name;

In the above query, the id is the primary key column of the table, you should replace it with the primary key column of your own table.

Please remember to back up your data before proceeding with this operation to prevent any unexpected issues.

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