mysql中怎么新建数据库连接

mysql -u username -p -h hostname

import mysql.connector

# 创建数据库连接
conn = mysql.connector.connect(
  host="hostname",
  user="username",
  password="password"
)

# 创建游标对象
cursor = conn.cursor()

# 执行SQL查询
cursor.execute("CREATE DATABASE new_database")

# 关闭游标和连接
cursor.close()
conn.close()

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

public class Main {
    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;

        try {
            // 注册驱动
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 创建数据库连接
            conn = DriverManager.getConnection("jdbc:mysql://hostname:port/database", "username", "password");

            // 创建Statement对象
            stmt = conn.createStatement();

            // 执行SQL语句
            String sql = "CREATE DATABASE new_database";
            stmt.executeUpdate(sql);

            System.out.println("Database created successfully");
        } catch (SQLException | ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            try {
                // 关闭Statement和连接
                if (stmt != null)
                    stmt.close();
                if (conn != null)
                    conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}