Failed to Connect to MySQL at localhost:3306 with user root

Question

I use Mysql Workbench to connect my database,[

Hostname Port and Username are as shown in figure ,and password is right.When I click Test Connection ,it show as above.But if i use 3307 in place of 3306 as port,it connect sucessfully. What matter lead that and how I fix it?

I use macbook pro and I don't know check which my.cnf. I use sudo vim /usr/local/mysql/my.cnf in terminal .
And the my.cnf is as below:

[mysqld] 
 sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES            

And I rewite it as below:

[client]
port=3306
socket=/tmp/mysql.sock

[mysqld]
port=3306
socket=/tmp/mysql.sock
key_buffer_size=16M
max_allowed_packet=8M 
[mysqldump]
quick 

But it does not work.

Answer 1

Steps:

1 - Right click on your task bar -->Start Task Manager

2 - Click on Services button (at bottom).

3 - Search for MYSQL57

4 - Right Click on MYSQL57 --> Start

Now again start your mysql-cmd-prompt or MYSQL WorkBench

Answer 2

Open System Preference > MySQL > Initialize Database > Use Legacy Password Encription