MYSQLデータベース操作
3668 ワード
SQL分類
データベース操作 1.データベース作成
次のように正常に印刷されました.
Query OK, 1 row affected, 1 warning (0.05 sec) 2.データベースの表示
クエリは次のように印刷されました.
mysql> show databases; +--------------------+ | Database | +--------------------+ | day06 | | day06_1 | | day06_2 | | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 7 rows in set (0.00 sec)
+----------+----------------------------------------------------------------------------------------------+ | Database | Create Database | +----------+----------------------------------------------------------------------------------------------+ | day06 | CREATE DATABASE 3.データベース操作の変更
変更前に次のように印刷します.
mysql> mysql> show create database day06_1; +----------+------------------------------------------------------------------+ | Database | Create Database | +----------+------------------------------------------------------------------+ | day06_1 | CREATE DATABASE
変更
mysql> alter database day06_1 character set gbk; Query OK, 1 row affected (0.06 sec)
変更後、次のように印刷されます.
mysql> show create database day06_1; +----------+-----------------------------------------------------------------+ | Database | Create Database | +----------+-----------------------------------------------------------------+ | day06_1 | CREATE DATABASE 4.データベースの削除
次のように印刷します.
データベースの削除
mysql> drop database day06_1; Query OK, 0 rows affected (0.04 sec)
クエリーデータベース、day 06_1は削除されたことを示します
mysql> show databases; +--------------------+ | Database | +--------------------+ | day06 | | day06_2 | | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 6 rows in set (0.00 sec) 5.その他のデータベース操作
次のように印刷します.
mysql> use day06; Database changed
mysql> select database(); +------------+ | database() | +------------+ | day06 | +------------+ 1 row in set (0.01 sec)
DDL ( )
- Data Definition Language
, 、 、
DML ( )
- Data Manipulation Language
,
update, insert, delete ---
DCL ( )
– Data Control Language
grant,revoke,if…else,while,begin transaction
DQL ( )
– Data Query Language
select
データベース操作
:
create database ;
: create database day06;
:
create database character set ;
: create database day06_1 character set utf8;
:
create database character set collate ;
: create database day06_2 character set utf8 collate utf8_bin;
次のように正常に印刷されました.
Query OK, 1 row affected, 1 warning (0.05 sec)
show databases;
show create database ;
:show create database day06;
:show create database day06_1;
クエリは次のように印刷されました.
mysql> show databases; +--------------------+ | Database | +--------------------+ | day06 | | day06_1 | | day06_2 | | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 7 rows in set (0.00 sec)
+----------+----------------------------------------------------------------------------------------------+ | Database | Create Database | +----------+----------------------------------------------------------------------------------------------+ | day06 | CREATE DATABASE
day06
/*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */| +----------+----------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)
alter database character set ;
: alter database day06_1 character set gbk;
変更前に次のように印刷します.
mysql> mysql> show create database day06_1; +----------+------------------------------------------------------------------+ | Database | Create Database | +----------+------------------------------------------------------------------+ | day06_1 | CREATE DATABASE
day06_1
/*!40100 DEFAULT CHARACTER SET utf8 */| +----------+------------------------------------------------------------------+ 1 row in set (0.00 sec) 変更
mysql> alter database day06_1 character set gbk; Query OK, 1 row affected (0.06 sec)
変更後、次のように印刷されます.
mysql> show create database day06_1; +----------+-----------------------------------------------------------------+ | Database | Create Database | +----------+-----------------------------------------------------------------+ | day06_1 | CREATE DATABASE
day06_1
/*!40100 DEFAULT CHARACTER SET gbk */| +----------+-----------------------------------------------------------------+ 1 row in set (0.00 sec) drop database ;
: drop database day06_1;
次のように印刷します.
データベースの削除
mysql> drop database day06_1; Query OK, 0 rows affected (0.04 sec)
クエリーデータベース、day 06_1は削除されたことを示します
mysql> show databases; +--------------------+ | Database | +--------------------+ | day06 | | day06_2 | | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 6 rows in set (0.00 sec)
use ;
: use day06;
:select database();
次のように印刷します.
mysql> use day06; Database changed
mysql> select database(); +------------+ | database() | +------------+ | day06 | +------------+ 1 row in set (0.01 sec)