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$ mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 59
Server version: 5.7.20 MySQL Community Server (GPL)

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

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>

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数据库

创建

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mysql> create database Leetcode;
Query OK, 1 row affected (0.01 sec)

选择

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mysql> use Leetcode;
Database changed

删除

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mysql> drop database Leetcode;

表处理

创建

选择数据库后，输入建表语句：

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mysql> create table if not exists Question (
    -> p_id INT NOT NULL,
    -> frontend_id INT NOT NULL,
    -> title_slug TINYTEXT,
    -> title TINYTEXT,
    -> difficulty INT,
    -> status INT,
    -> paid_only INT,
    -> is_favor INT,
    -> frequency INT,
    -> progress INT,
    -> likes INT,
    -> dislikes INT,
    -> PRIMARY KEY (p_id))
    -> ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.03 sec)

ENGINE 设置存储引擎，CHARSET 设置编码。

查看表结构：

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mysql> show tables;
+--------------------+
| Tables_in_leetcode |
+--------------------+
| Question           |
+--------------------+
1 row in set (0.00 sec)
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mysql> desc Question;
+-------------+----------+------+-----+---------+-------+
| Field       | Type     | Null | Key | Default | Extra |
+-------------+----------+------+-----+---------+-------+
| p_id        | int(11)  | NO   | PRI | NULL    |       |
| frontend_id | int(11)  | NO   |     | NULL    |       |
| title_slug  | tinytext | YES  |     | NULL    |       |
| title       | tinytext | YES  |     | NULL    |       |
| difficulty  | int(11)  | YES  |     | NULL    |       |
| status      | int(11)  | YES  |     | NULL    |       |
| paid_only   | int(11)  | YES  |     | NULL    |       |
| is_favor    | int(11)  | YES  |     | NULL    |       |
| frequency   | int(11)  | YES  |     | NULL    |       |
| progress    | int(11)  | YES  |     | NULL    |       |
| likes       | int(11)  | YES  |     | NULL    |       |
| dislikes    | int(11)  | YES  |     | NULL    |       |
+-------------+----------+------+-----+---------+-------+
12 rows in set (0.01 sec)

修改表名

将表明orders改为Orders：

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mysql> rename table orders to Orders;
Query OK, 0 rows affected (0.03 sec)

删除表

删除Orders表：

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mysql> drop table Orders;

字段处理

修改类型

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mysql> alter table Question modify column p_id int;

增加

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mysql> alter table Question add brief_introduce text not Null;

删除

[]内内容可重复多条。

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mysql> alter table Question drop column likes[, drop column dislikes];