How to Delete a Range of Rows in MySQL without Using OFFSET in DELETE Statement?

Deleting Rows with a Range in MySQL

When attempting to delete a specific range of rows from a table using the LIMIT clause in MySQL, an error can occur. To illustrate, the following query aims to delete a range of 50 rows, starting from the 20th row ordered by timestamp in descending order:

DELETE FROM `chat_messages` ORDER BY `timestamp` DESC LIMIT 20, 50;

However, upon executing this query, an error message is encountered due to an invalid syntax, specifically at the OFFSET value (50).

Limitation of LIMIT Clause in DELETE Statement

The root cause of the error lies in the inability to use OFFSET in the LIMIT clause of DELETE statements. This is a significant distinction from SELECT statements, which allow both LIMIT and OFFSET to specify the starting point and number of rows to retrieve.

Workaround for Range Deletion

To circumvent this limitation, a workaround is necessary. By utilizing a subquery nested within the DELETE statement, the range of rows can be accurately targeted and removed. This approach involves the following steps:

1. Identify the target rows using a subquery that selects the identifiers (e.g., primary key) of the rows within the desired range. This subquery should order the rows appropriately to ensure the correct range is selected.
2. Incorporate the subquery into the DELETE statement's WHERE clause, using the IN operator. This ensures that only the rows identified by the subquery are targeted for deletion.

Here's an example of a modified query using this workaround:

DELETE FROM `chat_messages` 
WHERE `id` IN (
    SELECT `id` FROM (
        SELECT `id` FROM `chat_messages`
        ORDER BY `timestamp` DESC
        LIMIT 20, 50
    ) AS `x`
)

In this query, the primary key column id is assumed, although it can be modified to the appropriate column name in your specific scenario.

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