搜索引擎--范例：谈谈django--mysql数据库的一些常用命令

现在基本没有什么能离得开数据库了，django我一直用的都是mysql的数据库，这次和大家说说django--mysql数据库的一些常用命令吧

1：命令行登陆mysql

C:UsersAdministrator>mysql -uroot -p
Enter password: ********

2：创建一个新的数据库并使用它

mysql> create database t;
Query OK, 1 row affected (0.02 sec)

mysql> use t;
Database changed

3：说点注意问题，我们先练show一下

mysql> show create database t;
+----------+--------------------------------------------------------------+
| Database | Create Database                                              |
+----------+--------------------------------------------------------------+
| t        | CREATE DATABASE `t` /*!40100 DEFAULT CHARACTER SET latin1 */ |
+----------+--------------------------------------------------------------+
1 row in set (0.00 sec)

注意到字符集是Latin1的

这样就无法存中文了，下面我们改一下设置吧，具体的命令我就不一一解说了，相信大家都能看得懂

mysql> show variables like 'char%';
+--------------------------+----------------------------------------------------
-----+
| Variable_name            | Value
     |
+--------------------------+----------------------------------------------------
-----+
| character_set_client     | latin1
     |
| character_set_connection | latin1
     |
| character_set_database   | latin1
     |
| character_set_filesystem | binary
     |
| character_set_results    | latin1
     |
| character_set_server     | latin1
     |
| character_set_system     | utf8
     |
| character_sets_dir       | C:Program FilesMySQLMySQL Server 5.5sharechars
ets |
+--------------------------+----------------------------------------------------
-----+
8 rows in set (0.01 sec)

mysql> set names utf8;
Query OK, 0 rows affected (0.01 sec)

mysql> show variables like 'char%';
+--------------------------+----------------------------------------------------
-----+
| Variable_name            | Value
     |
+--------------------------+----------------------------------------------------
-----+
| character_set_client     | utf8
     |
| character_set_connection | utf8
     |
| character_set_database   | latin1
     |
| character_set_filesystem | binary
     |
| character_set_results    | utf8
     |
| character_set_server     | latin1
     |
| character_set_system     | utf8
     |
| character_sets_dir       | C:Program FilesMySQLMySQL Server 5.5sharechars
ets |
+--------------------------+----------------------------------------------------
-----+
8 rows in set (0.00 sec)


mysql> set character_set_database = 'utf8';
Query OK, 0 rows affected (0.00 sec)

mysql> set character_set_server = 'utf8';
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like 'char%';
+--------------------------+----------------------------------------------------
-----+
| Variable_name            | Value
     |
+--------------------------+----------------------------------------------------
-----+
| character_set_client     | utf8
     |
| character_set_connection | utf8
     |
| character_set_database   | utf8
     |
| character_set_filesystem | binary
     |
| character_set_results    | utf8
     |
| character_set_server     | utf8
     |
| character_set_system     | utf8
     |
| character_sets_dir       | C:Program FilesMySQLMySQL Server 5.5sharechars
ets |
+--------------------------+----------------------------------------------------
-----+
8 rows in set (0.00 sec)

3：然后把1,2步骤中创建的数据库删掉，drop database +数据库名就可以了，然后重新创建就ok了

4：现在配置django中的配置文件

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql', # Add 'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'.
        'NAME': 'irsearch',                      # Or path to database file if using sqlite3.
        'USER': 'root',                      # Not used with sqlite3.
        'PASSWORD': '你的数据库的密码',                  # Not used with sqlite3.
        'HOST': '127.0.0.1',                      # Set to empty string for localhost. Not used with sqlite3.
        'PORT': '',                      # Set to empty string for default. Not used with sqlite3.
    }
}

5：写model.py了，简单举例，注意一定要用models.Model，否则没用的

#-*- coding: utf-8 -*-
from django.db import models

# Create your models here.
class Weibo(models.Model):
    """docstring for weibo"""
    w_id = models.IntegerField(primary_key=True)
    userid = models.CharField(max_length=20)
    username = models.CharField(max_length=30)
    content = models.CharField(max_length=2000)
    ptime = models.CharField(max_length=20)
    count = models.IntegerField()

6：django的SQL操作

python manage.py syncdb 初始化数据库或者更新数据库

python manage.py sql +数据库名字

python manage.py  sql +数据库名字 > t.sql 可以让这些数据写入到t.sql中，可以直接用

6：mysql的数据导入导出

其实强烈不建议使用mysql的数据导入导出的，可以通过后台直接读取数据库而进行数据库中的数据的导入导出

C:UsersAdministrator>mysqldump
Usage: mysqldump [OPTIONS] database [tables]
OR     mysqldump [OPTIONS] --databases [OPTIONS] DB1 [DB2 DB3...]
OR     mysqldump [OPTIONS] --all-databases [OPTIONS]
For more options, use mysqldump --help
                                           数据库名　  表名
C:UsersAdministrator>mysqldump -uroot -p irsearch search_stop >stop.txt
Enter password: ********

然后就可以在当前目录下看到stop.txt了，最好是输出到sql文件里面，然后就可以直接导入sql了

如果是导入新浪SAE的数据库，记得吧里面的LOCK，UNLOCK 指令去掉，因为SAE没有给你这个指令的权限

最后一定提醒大家，注意数据库的存放格式，否则你会哭的，相信我