php sql交换两个主要值

Question

$or1='607990';
$or2='607992';

UPDATE tbl_collection
SET or_number=
    CASE
        WHEN or_number='$or1'
        THEN $or2
        WHEN or_number='$or2'
        THEN $or1 
    END
    WHERE or_number IN($or2,$or1)

//Duplicate entry '607992' for key 'PRIMARY''

Answer 1

perform

Answer 2

删除or_number列的主键... 无法交换具有主键

的列的值