Importing SQL Server database from a .sql file
Create an empty database or if you have one already target that one. 

Open CMD with elevated privilege and run:

sqlcmd -S SERVERNAME -d MYDATABASE -U USERNAME -P PASSWORD -i C:\path\mysqlfile.sql -o C:\path\results.txt


basically: 


-S: is your servername or localhost
-d: is the database you are targeting
-U: is the username
-P: is the password
-i: is the path to your .sql file
-o: is where the logs file will be saved so if you had problem during the importation you can debug them