我尝试使用postgres 12.8对分区表执行Upsert。查询使用CTE执行插入操作，然后执行更新，但我收到以下错误：

[23505] ERROR: duplicate key value violates 
unique constraint "books_20221201_pkey" Detail: 
Key (book_id, book_name)=(1,"abcd") already exists.
 Where: SQL statement "INSERT INTO public.books_20221201 VALUES (NEW.*)"

下面是查询：

WITH bk_temp(book_id, book_name) AS (
            SELECT * FROM ( VALUES
                (1,
                 "abcd"
                )
            ) AS a(book_id, book_name))

            INSERT INTO books
            (book_id,
            book_name)
            (Select t.book_id, t.book_name
             FROM bk_temp t
            ON CONFLICT(book_id, book_name)
            DO Update
            SET book_name="defg");