// 连接默认数据库
dsn := "user=postgres password=123456 dbname=postgres port=5432 sslmode=disable TimeZone=Asia/Shanghai"
db, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})
if err != nil {
	panic(err.Error())
}
// 创建新数据库,双引号保持名称大写，否则pg会自动转小写
sqlinfo := fmt.Sprintf(`CREATE DATABASE "%s"`,dbName)
db.Exec(sqlinfo)
// 关闭postgres连接
DBConn,_ := db.DB()
DBConn.Close()
// 连接新建数据库
dsn = "user=postgres password=123456 dbname="+dbName+" port=5432 sslmode=disable TimeZone=Asia/Shanghai"
db, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})
if err != nil {
	panic(err.Error())
}