You can't specify target table 'PP' for update in FROM clause

This error message is usually encountered when trying to update a table that is being used as a subquery in the same UPDATE statement. The MySQL database does not allow this type of operation because it can create a conflict between the original data and the updated data.

To resolve this error, you can use a temporary table to store the results of the subquery and then use that table to update the target table. Another option is to rewrite the UPDATE statement using a JOIN clause instead of a subquery, which can avoid the conflict issue.

Here's an example of using a temporary table to update the target table:

CREATE TEMPORARY TABLE tmp_table AS 
SELECT * FROM PP WHERE some_condition;

UPDATE PP 
SET column1 = value1, column2 = value2 
WHERE id IN (SELECT id FROM tmp_table);

And here's an example of using a JOIN clause to update the target table:

UPDATE PP 
JOIN (SELECT id FROM PP WHERE some_condition) AS tmp_table 
ON PP.id = tmp_table.id 
SET column1 = value1, column2 = value2;

Both of these approaches can help you avoid the "Can't specify target table for update in FROM clause" error.