access denied for user root @ localhost [duplicate]

Answer 1

wamp's mysql default configuration sets username root with no password

$conn = mysqli_connect("localhost", "root", "");

the above code should work

Answer 2

if you are using localhost. it doesnt have password. you will just setup it like this:

<?php
mysql_connect("localhost", "root", "") or die(mysql_error());
mysql_select_db("database name here") or die(mysql_error());
?>

Answer 3

Let the following 2 lines fail if user exists and blahblah doesnt matter for now:

create user 'root'@'localhost' identified by 'blahblah';
create user 'root'@'127.0.0.1' identified by 'blahblah';

Do your grants:

grant all on *.* to 'root'@'localhost';
grant all on *.* to 'root'@'127.0.0.1';

Change the password to something you will remember:

set password for 'root'@'localhost' = password('NewPassword');
set password for 'root'@'127.0.0.1' = password('NewPassword');

See how many root users you have. A real user is a user/host combo. The password will show up hashed:

select user,host,password from mysql.user where user='root';

or

select user,host,authentication_string from mysql.user where user='root';

The 2nd one above is for MySQL 5.7

If you get more than the two users above, drop the others such as:

drop user 'root'@'%';   -- this is the wildcard hostname, can be a security risk
drop user 'root'@'::1';

Still have only 2? I hope so. Use the select stmts above to check.

Don't connect a user app using root. root is for maintenance only. It doesn't matter if it is server-side code, or if an admin is running it. Code that is not secured and/or injected with harmful statements gets to run as root. So there, that is why.