Mysql order by usage

The usage of Mysql order by has encountered some problems in the process of using order by today. It was found that the previous understanding of order by is incorrect. I saw the order by usage on the w3s website and thought it was to sort the selected data in ascending or descending ORDER of the keywords. When I tried to select the dataset data today, it is found that the query results obtained BY using order by and order by desc are completely different. According to your previous understanding, they should have the same results, but the internal ORDER is different. Www.2cto.com asked a colleague and checked the document. If we use order by (DESC) when executing the select statement, it first sorts all records BY keywords and then reads the required records in sequence, instead of selecting records first and then sorting them in descending order. A conceptual error, so remember to warn yourself. Author: Phoenix_Zhao