標籤：
1、資料庫（database）管理
1.1 create 建立資料庫
create database firstDB;
1.2 show 查看所有資料庫
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| firstDB |
| mysql |
| performance_schema |
+--------------------+
4 rows in set (0.00 sec)
1.3 alter 修改資料庫
alter 命令修改資料庫編碼：
預設建立的資料庫預設不支援中文字元，如果我們需要它支援中文字元，則將它的編碼設定為utf8格式：
mysql> ALTER DATABASE testDB CHARACTER SET UTF8;
Query OK, 1 row affected (0.00 sec)
1.4 use 使用資料庫
mysql> use firstDB;
Database changed
1.5 查看當前使用的資料庫
mysql> select database();
+------------+
| database() |
+------------+
| firstdb |
+------------+
1 row in set (0.00 sec)
1.6 drop 刪除資料庫
mysql> drop database firstDB;
Query OK, 0 rows affected (0.00 sec)
2、資料表（table）管理
我們首先建立一個資料庫，提供我們往後的使用：
mysql> create database testDB;
Query OK, 1 row affected (0.00 sec)
建立後記得用use命令進入（使用）資料庫，不然後面的操作都會不成功的。
2.1 create 建立表
mysql> create table PEOPLE (
-> ID int AUTO_INCREMENT PRIMARY KEY,
-> NAME varchar(20) not null,
-> AGE int not null,
-> BIRTHDAY datetime);
Query OK, 0 rows affected (0.01 sec)
2.2 show 顯示表
顯示當前資料庫所有的資料表
mysql> show tables;
+------------------+
| Tables_in_testdb |
+------------------+
| PEOPLE |
+------------------+
1 row in set (0.00 sec)
2.3 desc 查看錶結構
mysql> desc PEOPLE
-> ;
+----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+----------------+
| ID | int(11) | NO | PRI | NULL | auto_increment |
| NAME | varchar(20) | NO | | NULL | |
| AGE | int(11) | NO | | NULL | |
| BIRTHDAY | datetime | YES | | NULL | |
+----------+-------------+------+-----+---------+----------------+
4 rows in set (0.01 sec)
2.4 alter 修改表結構（增、刪、改）
預設建立的表不支援中文字元，所以需將表編碼設定為utf8：
mysql> ALTER TABLE KEYCHAIN CONVERT TO CHARACTER SET UTF8;
Query OK, 1 row affected (0.02 sec)
Records: 1 Duplicates: 0 Warnings: 0
2.4.1 insert 在表中添加列（欄位）
mysql> alter table PEOPLE add star BOOL;
Query OK, 0 rows affected (0.02 sec)
Records: 0 Duplicates: 0 Warnings: 0
提示：在MySQL裡，布爾類型會自動轉換為tinyint(1)類型。
我們不妨使用desc去查看一下PEOPLE表結構：
mysql> desc PEOPLE;
+----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+----------------+
| ID | int(11) | NO | PRI | NULL | auto_increment |
| NAME | varchar(20) | NO | | NULL | |
| AGE | int(11) | NO | | NULL | |
| BIRTHDAY | datetime | YES | | NULL | |
| star | tinyint(1) | YES | | NULL | |
+----------+-------------+------+-----+---------+----------------+
5 rows in set (0.00 sec)
現在，你該相信我了吧？
2.4.2 alter 修改表（列）欄位
mysql> alter table PEOPLE MODIFY star int;
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0
我們再次使用desc查看PEOPLE表結構：
mysql> desc PEOPLE;
+----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+----------------+
| ID | int(11) | NO | PRI | NULL | auto_increment |
| NAME | varchar(20) | NO | | NULL | |
| AGE | int(11) | NO | | NULL | |
| BIRTHDAY | datetime | YES | | NULL | |
| star | int(11) | YES | | NULL | |
+----------+-------------+------+-----+---------+----------------+
5 rows in set (0.00 sec)
2.4.3 delete 刪除表（列）欄位
mysql> alter table PEOPLE DROP column star;
Query OK, 0 rows affected (0.02 sec)
Records: 0 Duplicates: 0 Warnings: 0
刪除後，再次查看PEOPLE表結構：
mysql> desc PEOPLE;
+----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+----------------+
| ID | int(11) | NO | PRI | NULL | auto_increment |
| NAME | varchar(20) | NO | | NULL | |
| AGE | int(11) | NO | | NULL | |
| BIRTHDAY | datetime | YES | | NULL | |
+----------+-------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)
刪除欄位成功，現在我們已經不能看到star的欄位了。
2.4.4 rename 重新命名表名
mysql> RENAME TABLE PEOPLE TO NEW_PEOPLE;
Query OK, 0 rows affected (0.00 sec)
2.5 create 利用已有資料建立新表
mysql> create table newTable select * from PEOPLE;
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0
我們查看一下目前資料庫存在的表：
mysql> show tables;
+------------------+
| Tables_in_testdb |
+------------------+
| PEOPLE |
| newTable |
+------------------+
2 rows in set (0.00 sec)
3、資料的操作及管理
資料表的基本操作，包含增、刪、改、查資料。
以下命令均在PEOPLE表上操作。
3.1 增加資料（增）
PEOPLE表目前是沒有資料的，它是空的資料表，我們現在先添加一些資料。
insert into 命令添加資料：
mysql> insert into PEOPLE VALUES (null, ‘Anny‘, 22, ‘1992-05-22‘);
Query OK, 1 row affected (0.00 sec)
使用select命令查看錶（會在後面介紹），現在我們查看PEOPLE資料表的資料：
mysql> select * from PEOPLE;
+----+------+-----+---------------------+
| ID | NAME | AGE | BIRTHDAY |
+----+------+-----+---------------------+
| 1 | Anny | 22 | 1992-05-22 00:00:00 |
+----+------+-----+---------------------+
1 row in set (0.00 sec)
資料表現在有一條資料。
我們多添加幾條資料，如：
mysql> select * from PEOPLE;
+----+--------+-----+---------------------+
| ID | NAME | AGE | BIRTHDAY |
+----+--------+-----+---------------------+
| 1 | Anny | 22 | 1992-05-22 00:00:00 |
| 2 | Garvey | 23 | 1991-05-22 00:00:00 |
| 3 | Lisa | 25 | 1989-05-22 00:00:00 |
| 4 | Nick | 24 | 1990-05-22 00:00:00 |
| 5 | Rick | 24 | 1991-05-22 00:00:00 |
+----+--------+-----+---------------------+
5 rows in set (0.00 sec)
3.2 刪除資料（刪）
delete 命令刪除資料：
mysql> delete from PEOPLE where name = ‘Lisa‘;
Query OK, 1 row affected (0.01 sec)
重新查詢PEOPLE表：
mysql> select * from PEOPLE;
+----+--------+-----+---------------------+
| ID | NAME | AGE | BIRTHDAY |
+----+--------+-----+---------------------+
| 1 | Anny | 22 | 1992-05-22 00:00:00 |
| 2 | Garvey | 23 | 1991-05-22 00:00:00 |
| 4 | Nick | 24 | 1990-05-22 00:00:00 |
| 5 | Rick | 24 | 1991-05-22 00:00:00 |
+----+--------+-----+---------------------+
4 rows in set (0.00 sec)
已經看不到名為“Lisa”的資料了。
3.3 修改資料（改）
update 命令修改資料：
mysql> update PEOPLE set name=‘Calvin‘ where name = ‘Garvey‘;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
查詢PEOPLE表內容：
mysql> select * from PEOPLE;
+----+--------+-----+---------------------+
| ID | NAME | AGE | BIRTHDAY |
+----+--------+-----+---------------------+
| 1 | Anny | 22 | 1992-05-22 00:00:00 |
| 2 | Calvin | 23 | 1991-05-22 00:00:00 |
| 4 | Nick | 24 | 1990-05-22 00:00:00 |
| 5 | Rick | 24 | 1991-05-22 00:00:00 |
+----+--------+-----+---------------------+
4 rows in set (0.00 sec)
名為“Garvey”的記錄已經修改為“Calvin”。
3.4 查詢資料（查）
select 命令查詢資料，最簡單的就是查詢表的所有資料，也就是我們最初使用到的那條命令：
mysql> select * from PEOPLE;
+----+--------+-----+---------------------+
| ID | NAME | AGE | BIRTHDAY |
+----+--------+-----+---------------------+
| 1 | Anny | 22 | 1992-05-22 00:00:00 |
| 2 | Calvin | 23 | 1991-05-22 00:00:00 |
| 4 | Nick | 24 | 1990-05-22 00:00:00 |
| 5 | Rick | 24 | 1991-05-22 00:00:00 |
+----+--------+-----+---------------------+
4 rows in set (0.00 sec)
格式：select * from <表名>，*代表所有欄位。
查詢資料時也可指定顯示的（列）欄位：
mysql> select NAME, AGE, BIRTHDAY from PEOPLE;
+--------+-----+---------------------+
| NAME | AGE | BIRTHDAY |
+--------+-----+---------------------+
| Anny | 22 | 1992-05-22 00:00:00 |
| Calvin | 23 | 1991-05-22 00:00:00 |
| Nick | 24 | 1990-05-22 00:00:00 |
| Rick | 24 | 1991-05-22 00:00:00 |
+--------+-----+---------------------+
4 rows in set (0.00 sec)
格式：select <欄位名,欄位名,…> from <表名>。
MySQL 資料庫、資料表、資料的基本操作
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