創建數據庫 語法：

pyvip@Vip:~$ mysql -uxlong -pqwe123         #使用普通用戶登錄Mysql
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 14
Server version: 5.7.21-0ubuntu0.16.04.1 (Ubuntu)

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Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.

mysql> create database mybd1;    #創建一個名為 "mydb1" 的數據庫
Query OK, 1 row affected (0.00 sec)

mysql> show databases;             #查看創建的數據庫 "mydb1"
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mybd1              |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

mysql> drop database mybd1;    #刪除名為 "mydb1" 的數據庫，也可以使用這樣語法刪除數據庫（drop database if exists  mydb1;）
Query OK, 0 rows affected (0.00 sec)

mysql> show databases;    #查看刪除結果， "mydb1" 數據庫已經被刪除了
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)

mysql> SELECT DATABASE();  #查看當前在數據庫的目錄，類似linux中的pwd。 
+------------+             #這個結果表示，當前只是在mysql大廳裏面，還沒有進入數據庫中。
| DATABASE() |
+------------+
| NULL       |
+------------+
1 row in set (0.01 sec)      

進入數據庫：

mysql> create database mydb123;    #創建一個數據庫
Query OK, 1 row affected (0.00 sec)

mysql> show databases;     #查看創建結果，mydb123 已經創建完成
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mydb123            |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

mysql> use mydb123;    #進入創建的mydb123 數據庫
Database changed
mysql> select database();  #查看當前所在數據庫目錄，已經進入mydb123 數據庫。
+------------+
| database() |
+------------+
| mydb123    |
+------------+
1 row in set (0.00 sec)

mysql> 

Mysql 數據庫創建與刪除(基礎2)