Phpmyadmin method to import large amounts of data in SQL statement format

The contents of SQL. PHP file are as follows:

<? 
system("mysql -uroot -pmypassword database < a.sql"); 
print "sql ok"; 
?> 

Where root represents the database user name, mypassword represents the password of root, database represents the name of the database to be imported, and a.sql represents the file name of the database file