MySQLdb是Python连接MySQL的模块,下面介绍一下源码方式安装MySQLdb:
MySQLdb.connection():
Create a connection to the database. It is strongly recommended
that you only use keyword parameters. Consult the MySQL C API
documentation for more information.
host
string, host to connect
user
string, user to connect as
passwd
string, password to use
db
string, database to use
port
integer, TCP/IP port to connect to
unix_socket
string, location of unix_socket to use
conv
conversion dictionary, see MySQLdb.converters
connect_timeout
number of seconds to wait before the connection attempt
fails.
compress
if set, compression is enabled
named_pipe
if set, a named pipe is used to connect (Windows only)
init_command
command which is run once the connection is created
read_default_file
file from which default client values are read
read_default_group
configuration group to use from the default file
cursorclass
class object, used to create cursors (keyword only)
use_unicode
If True, text-like columns are returned as unicode objects
using the connection's character set. Otherwise, text-like
columns are returned as strings. columns are returned as
normal strings. Unicode objects will always be encoded to
the connection's character set regardless of this setting.
charset
If supplied, the connection character set will be changed
to this character set (MySQL-4.1 and newer). This implies
use_unicode=True.
sql_mode
If supplied, the session SQL mode will be changed to this
setting (MySQL-4.1 and newer). For more details and legal
values, see the MySQL documentation.
client_flag
integer, flags to use or 0
(see MySQL docs or constants/CLIENTS.py)
ssl
dictionary or mapping, contains SSL connection parameters;
see the MySQL documentation for more details
(mysql_ssl_set()). If this is set, and the client does not
support SSL, NotSupportedError will be raised.
local_infile
integer, non-zero enables LOAD LOCAL INFILE; zero disables
autocommit
If False (default), autocommit is disabled.
If True, autocommit is enabled.
If None, autocommit isn't set and server default is used.
windows AND linux :
pip install MySQLdb
其它情况:
安装完成,到你的python安装目录下的site-packages目录里检查以下文件是否存在,如果存在即代表安装成功了
Linux:MySQL_python-1.2.3c1-py2.6-linux-i686.egg
Mac OS X:MySQL_python-1.2.3c1-py2.6-macosx-10.4-x86_64.egg
注:如果碰到mysql_config not found的问题,有两种方法解决:
1)ln -s /usr/local/mysql/bin/mysql_config /usr/local/bin/mysql_config
将mysql_confi从你的安装目录链接到/usr/local/bin目录下,这样就可以在任意目录下访问了(也可以放到/usr/bin)
2)编辑源码文件夹的site.cfg文件,去掉#mysql_config = /usr/local/bin/mysql_config前的注释#,修改后面的路径为你的mysql_config真正的目录就可以了。(如果不知道mysql_config在哪里,运行命令:whereis mysql_config)
注:如果碰到import error: libmysqlclient.so.18: cannot open shared object file: No such file or directory
解决方法: locate or find libmysqlclient.so.18
link path/libmysqlclient.so.18 /usr/lib/libmysqlclient.so.18
vi /etc/ld.so.conf //加入libmysqlclient.so.18 所在的目录
插入: /usr/lib/
保存退出后执行/sbin/ldconfig生效
测试方法
1)运行命令python进入python运行环境
2)输入以下python代码进行测试
import MySQLdb
test=MySQLdb.connect(db='mydb',host='myhost',user='u',passwd='p')
cur = test.cursor()
cur.execute('show databases;')
for data in cur.fetchall():
print data
3)如果你在屏幕上看到了你几个数据库的库名的输出代表你安装成功了
可能碰到的问题
问题:ImportError: libmysqlclient_r.so.16: cannot open shared object file: No such file or directory
原因是python无法找到mysql目录下的libmysqlclient_r.so.16动态库,其实MySQLdb是调用mysql的c函数库.所以本机上首先得安装了mysql
然后: export LD_LIBRARY_PATH=/usr/local/mysql/lib/mysql:$LD_LIBRARY_PATH
并且将/usr/local/mysql5.1/lib/mysql 放入/etc/ld.so.conf中
/etc/ld.so.conf改后内容为:
include ld.so.conf.d/*.conf
/usr/local/mysql5.1/lib/mysql
最后重新再测试一下,就不会有上面的问题了
MySQLdb操作:
Python代码
MySQLdb : create database
#!/usr/bin/env python
#coding=utf-8
###################################
#MySQLdb create database
#
##################################
import MySQLdb
#建立和数据库系统的连接
conn = MySQLdb.connect(host='localhost', user='root',passwd='longforfreedom')
#获取操作游标
cursor = conn.cursor()
#执行SQL,创建一个数据库.
cursor.execute("""create database python """)
#关闭连接,释放资源
cursor.close();
创建数据库,创建表,插入数据,插入多条数据
Python代码:
#!/usr/bin/env python
#coding=utf-8
###################################
#MySQLdb 示例
#
##################################
import MySQLdb
#建立和数据库系统的连接
conn = MySQLdb.connect(host='localhost', user='root',passwd='longforfreedom')
#获取操作游标
cursor = conn.cursor()
#执行SQL,创建一个数据库.
cursor.execute("""create database if not exists python""")
#选择数据库
conn.select_db('python');
#执行SQL,创建一个数据表.
cursor.execute("""create table test(id int, info varchar(100)) """)
value = [1,"inserted ?"];
#插入一条记录
cursor.execute("insert into test values(%s,%s)",value);
values=[]
#生成插入参数值
for i in range(20):
values.append((i,'Hello mysqldb, I am recoder ' + str(i)))
#插入多条记录
cursor.executemany("""insert into test values(%s,%s) """,values);
#关闭连接,释放资源
cursor.close();
#!/usr/bin/env python
#coding=utf-8
###################################
#MySQLdb 示例 #
##################################
import MySQLdb
#建立和数据库系统的连接
conn = MySQLdb.connect(host='localhost', user='root',passwd='longforfreedom')
#获取操作游标
cursor = conn.cursor()
#执行SQL,创建一个数据库.
cursor.execute("""create database if not exists python""")
#选择数据库
conn.select_db('python');
#执行SQL,创建一个数据表.
cursor.execute("""create table test(id int, info varchar(100)) """)
value = [1,"inserted ?"];
#插入一条记录
cursor.execute("insert into test values(%s,%s)",value);
values=[]
#生成插入参数值
for i in range(20):
values.append((i,'Hello mysqldb, I am recoder ' + str(i)));
#插入多条记录
cursor.executemany("""insert into test values(%s,%s) """,values);
#关闭连接,释放资源
cursor.close();
查询和插入的流程差不多,只是多了一个得到查询结果的步骤
Python代码:
#!/usr/bin/env python
#coding=utf-8
#
# MySQLdb 查询
#
#######################################
import MySQLdb
conn = MySQLdb.connect(host='localhost', user='root', passwd='longforfreedom',db='python')
cursor = conn.cursor()
count = cursor.execute('select * from test')
print '总共有 %s 条记录',count
#获取一条记录,每条记录做为一个元组返回
print "只获取一条记录:"
result = cursor.fetchone();
print result
#print 'ID: %s info: %s' % (result[0],result[1])
print 'ID: %s info: %s' % result
#获取5条记录,注意由于之前执行有了fetchone(),所以游标已经指到第二条记录了,也就是从第二条开始的所有记录
print "只获取5条记录:"
results = cursor.fetchmany(5)
for r in results:
print r
print "获取所有结果:"
#重置游标位置,0,为偏移量,mode=absolute | relative,默认为relative,
cursor.scroll(0,mode='absolute')
#获取所有结果
results = cursor.fetchall()
for r in results:
print r
conn.close()
默认mysqldb返回的是元组,这样对使用者不太友好,也不利于维护
下面是解决方法
import MySQLdb
import MySQLdb.cursors
conn = MySQLdb.Connect (
host = 'localhost', user = 'root' ,
passwd = '', db = 'test', compress = 1,
cursorclass = MySQLdb.cursors.DictCursor, charset='utf8') // <- important
cursor = conn.cursor()
cursor.execute ("SELECT name, txt FROM table")
rows = cursor.fetchall()
cursor.close()
conn.close()
for row in rows:
print row ['name'], row ['txt'] # bingo!
another (even better) way is:
conn = MySQLdb . Connect (
host = ' localhost ', user = 'root' ,
passwd = '', db = 'test' , compress = 1)
cursor = conn.cursor (cursorclass = MySQLdb.cursors.DictCursor)
# ...
# results by field name
cursor = conn.cursor()
# ...
# ...results by field number