基本的なデータベース操作ステートメントとは何ですか?

SHOW DATABASES;  //查询数据库SHOW 
CREATE DATABASE score; //查询数据库的结构CREATE 
DATABASE score DEFAULT CHARSET utf8; //创建数据库
USE score;  //使用score数据库
DROP DATABASE score;  //删除数据库

SHOW TABLES;      //显示数据库中的表CREATE TABLE score(
sno INT PRIMARY KEY AUTO_INCREMENT,
course VARCHAR(20),
sscore SMALLINT);   //创建表SHOW CREATE TABLE score;   //显示构造表语句DESC score;　　 //显示表结
ALTER TABLE score
ADD startTime DATE NOT NULL;   //添加字段ALTER TABLE score
DROP startTime;   //删除字段ALTER TABLE score
MODIFY course VARCHAR(50);   //修改字段类型ALTER TABLE score
CHANGE startTime endTime DATE;   //修改字段名DROP TABLE score;  //删除表

INSERT INTO score(course,sscore)
VALUES('语文',80);   //添加数据UPDATE score
SET sscore=90WHERE sno=1;    //修改数据DELETE FROM score
WHERE sno=1;   //删除数据

SELECT * FROM score;   //查询所有字段数据

SHOW VARIABLES LIKE 'character%';

Variable_name    Value
character_set_client    utf8
character_set_connection    utf8
character_set_database    utf8
character_set_filesystem    binary
character_set_results    utf8
character_set_server    utf8
character_set_system    utf8
character_sets_dir    C:\\Program Files\\MySQL\\MySQL Server 5.7\\share\\charsets\\

SET character_set_client='gbk';