"Novice of the database" failed to create database procedure, "master" denied CREATE DATABASE permission problem __ db

Problem Description: SQL Server Authentication Mode login, CREATE DATABASE error: "Master" rejected the Create DB permission issue.

Solution: First, re-login with Windows mode, click "Security-> Login", and then there will be a drop-down list of login names,

Then, double click on the sign-in name that you last failed, and the following interface appears:

Select "Server Role", then appear the following interface, all tick on the top (PS: Novice do not understand all tick)

You can then log in again with the authentication method, creating the database without error.