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MySQL数据库基本操作
基本操作有：查看有哪些数据库、查看有哪些表、创建数据库、创建表、查看表信息、向表中插入数据等 # 查看有哪些数据库 MariaDB [(none)]> show databases; 切换到test数据库 MariaDB [(none)]> use test; 查看当前数据库有哪些表 MariaDB [test]> show tables;Empty set (0.000 sec) # 表明当前数据库是空的 如果test数据库不存在，则创建 MariaDB [test]> CREATE DATABASE IF NOT EXISTS test; 在数据库test种创建表三个表：books、authors、series MariaDB [test]> CREATE TABLE IF NOT EXISTS books ( # 创建books表（前提是books表不存在，如果已经存在，则不创建）-> BookID INT NOT NULL PRIMARY KEY AUTO_INCREMENT,-> Title VARCHAR(100) NOT NULL,-> SeriesID INT, AuthorID INT);Query OK, 0 rows affected (0.033 sec) MariaDB [test]> CREATE TABLE IF NOT EXISTS authors # 创建authors表（前提是authors表不存在，如果已经存在，则不创建）-> (id INT NOT NULL PRIMARY KEY AUTO_INCREMENT);Query OK, 0 rows affected (0.005 sec) MariaDB [test]> CREATE TABLE IF NOT EXISTS series # 创建series表（前提是series表不存在，如果已经存在，则不创建）-> (id INT NOT NULL PRIMARY KEY AUTO_INCREMENT);Query OK, 0 rows affected (0.005 sec) 接下来我们再来看看表是否添加成功 MariaDB [test]> show tables;+----------------+| Tables_in_test |+----------------+| authors || books || series |+----------------+3 rows in set (0.000 sec) 向books表中插入数据 MariaDB [test]> INSERT INTO books (Title,SeriesID,AuthorID)-> VALUES('The Fellowship of the Ring',1,1),-> ('The Two Towers',1,1), ('The Return of the King',1,1),-> ('The Sum of All Men',2,2), ('Brotherhood of the Wolf',2,2),-> ('Wizardborn',2,2), ('The Hobbbit',0,1);Query OK, 7 rows affected (0.004 sec)Records: 7 Duplicates: 0 Warnings: 0 查看表信息 MariaDB [test]> describe books;+----------+--------------+------+-----+---------+----------------+| Field | Type | Null | Key | Default | Extra |+----------+--------------+------+-----+---------+----------------+| BookID | int(11) | NO | PRI | NULL | auto_increment || Title | varchar(100) | NO | | NULL | || SeriesID | int(11) | YES | | NULL | || AuthorID | int(11) | YES | | NULL | |+----------+--------------+------+-----+---------+----------------+4 rows in set (0.002 sec) 查询数据（从表中查询数据） MariaDB [test]> select * from books;+--------+----------------------------+----------+----------+| BookID | Title | SeriesID | AuthorID |+--------+----------------------------+----------+----------+| 1 | The Fellowship of the Ring | 1 | 1 || 2 | The Two Towers | 1 | 1 || 3 | The Return of the King | 1 | 1 || 4 | The Sum of All Men | 2 | 2 || 5 | Brotherhood of the Wolf | 2 | 2 || 6 | Wizardborn | 2 | 2 || 7 | The Hobbbit | 0 | 1 |+--------+----------------------------+----------+----------+7 rows in set (0.000 sec) 小知识：sql语句允许换行，直到遇到分号+回车才会认为sql语句输入结束，进入执行阶段 ...
