How to deal with uploading CSV file content to the database

The CSV file content is uploaded to the database. I have a lot of CSV format data to be uploaded to MYSQL, but there are more than 20 rows in front of it. useless data. how can I delete the previous data and upload the remaining useful data, could you please give me a thought or CODE? ---------- What should I do if CSV of different structures is used? Are there ready-made classes? For example, a.csv1_1%2%3123b.csv namesexage CSV file content is uploaded to the database.
I have a lot of CSV data to upload to MYSQL

However, there are more than 20 rows of useless data. how can I delete the previous data and upload the remaining useful data? could you please give me some ideas or CODE?

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What should I do if CSV files of different structures are used? Are there ready-made classes?
For example:
A.csv

Title 1 title 2 title 3
1 2 3


B .csv

Name sex age
.......

====================================

I am a newbie. thank you for your help!



------ Solution --------------------
This is an example. For more information, see:

PHP code

$ Arr = file ("aa.csv" );file_put_contents('aa.csv ', join ("", array_slice ($ arr, 20); mysql_connect ('localhost', "root ",''); $ SQL = "load data infile 'absolute path/aa.csv 'into table test.csv fields terminated by', '"; // database name: test, table name: csvmysql_query ($ SQL) or die (mysql_error ());
------ Solution --------------------

  
   Discussion
   

   
I mean, can I delete the first N rows of data in PHP. Please advise!