Open or not open, that is the stupid question.

You can use mkisofs to backup your filesystem. # mkisofs --allow-lowercase --allow-multidot -r -o ./stanley.iso ./stanley # mount -F hsfs `pwd`/stanley.iso /tmp/t Wish this helps. regards, Stanley Huang

This is my stored procedure template: -- myparent_block:BEGIN   -- declare variables   DECLARE fetch_id INT DEFAULT NULL;   DECLARE loop_done BOOLEAN DEFAULT FALSE;   -- declare conditions   DECLARE condition_not_found CONDITION FOR SQLSTATE '02000';   -- declare cursors   DECLARE cursor_myparent CURSOR FOR     SELECT id FROM myparent WHERE serialnumber=sn;   -- declare handlers   DECLARE continue HANDLER FOR condition_not_found     SET loop_done := TRUE;   OPEN cursor_myparent;   REPEAT     FETCH cursor_myparent into fetch_id;     DELETE FROM mychild WHERE pid=fetch_id;   UNTIL loop_done END REPEAT;   CLOSE cursor_device;   DELETE FROM myparent WHERE fkid=fetchfkid; END myparent_block; -- Wish this helps. regards, Stanley Huang

in south project: http://south.aeracode.org/docs/databaseapi.html#database-specific-issues South automatically exposes the correct set of database API operations as south.db.db ; it detects which database backend you’re using from your Django settings file. It’s usually imported using: from south.db import db If you’re using multiple database support (Django 1.2 and higher), there’s a corresponding south.db.dbs dictionary which contains a DatabaseOperations object (the object which has the methods defined above) for each database alias in your configuration file: from south.db import dbs dbs [ 'users' ] . create_table ( ... ) You can tell which backend you’re talking to inside of a migration by examining db.backend_name - it will be one of postgres , mysql , sqlite3 , pyodbc or oracle . It should worth to try~ Wish this helps. regards, Stanley Huang

I cannot fine char data type in Django 1.2 beta 1 . So I try to build up my own data type field. My sample code as following: from django.db import models # Create your models here. from django.db.models import * #from django.db import connection #from django.db.models.fields.subclassing import LegacyConnection #from django.db.models.query_utils import QueryWrapper #from django.conf import settings #from django import forms #from django.core import exceptions, validators #from django.utils.datastructures import DictWrapper #from django.utils.functional import curry #from django.utils.itercompat import tee #from django.utils.text import capfirst from django.utils.translation import ugettext_lazy as _ #from django.utils.encoding import smart_unicode, force_unicode, smart_str #from django.utils import datetime_safe # Create your models here. # This is a much more flexible example. class myCharField(Field):     def __init__(self, *args, **kwargs): ...

If you want to remove all folders without any file, you can use the command to remove it. # find ./ | sort -r | xargs rmdir 2>/dev/null Wish this helps. regards, Stanley Huang

If you have the same problem, you can use --language to assign language directory, Ex: # ./bin/mysqld --user=mysql 100415 14:43:50 [ERROR] Can't find messagefile '/usr/share/english/errmsg.sys' 100415 14:43:50 [Note] Plugin 'FEDERATED' is disabled. 100415 14:43:50  InnoDB: Started; log sequence number 0 4604259 100415 14:43:50 [ERROR] Aborting 100415 14:43:50  InnoDB: Starting shutdown... 100415 14:43:56  InnoDB: Shutdown completed; log sequence number 0 4604259 100415 14:43:56 [Note] # # ./bin/mysqld --user=mysql --language=./share/english 100415 14:43:58 [Note] Plugin 'FEDERATED' is disabled. 100415 14:43:58  InnoDB: Started; log sequence number 0 4604259 100415 14:43:58 [Note] Event Scheduler: Loaded 0 events 100415 14:43:58 [Note] ./bin/mysqld: ready for connections. Version: '5.1.45'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server (GPL) Wish this helps. regards, Stanley Huang

If you want to check a port which is used by what process. You can use the command to get information: # netstat -an -tap | grep :::443 tcp6       0      0 :::443                  :::*                    LISTEN      31462 / java # ps -fp 31462 root     31462     1  7 10:46 pts/1    00:00:43 /opt/java/jre//bin/ java ... Wish this helps. regards, Stanley Huang

I wrote a shell script for install ubuntu package: #!/bin/bash #apt-get update; apt-cache search key word; ## update apt-get cache and search key word #apt-get install pkg-name; apt-get upgrade; ## install package #apt-get remove pkg-name;                   ## remove package #grep install /var/log/dpkg.log             ## apt-get install history #ls /var/lib/dpkg/info                      ## apt-get installed packages #dpkg -L tomcat6                            ## list apt-get specific installed packages ## show usage showUsage() {   cat <<EOF Usage:   $0 [-u] [-s] package1 p...

If you want to use Chinese Input in Ubuntu, you can setup the environment with scim. The commands as the following: # apt-get install scim scim-pinyin scim-chewing scim-tables-zh scim-qtimm im-switch # im-switch -s scim Relogin again, and enjoy it! Wish this helps. regards, Stanley Huang

Install unrar on CentOS 5.4 # wget http://dag.wieers.com/packages/unrar/unrar-3.6.2-1.el4.rf.i386.rpm # rpm -ivh unrar-3.6.2-1.el4.rf.i386.rpm Run it: # unrar e -kb myRar.rar Wish this helps. regards, Publish Post Stanley Huang

One Pattern a day, keep refactoring away~ Wish this helps. regards, Stanley Huang

In myCxn.py: import MySQLdb cxn = MySQLdb.connect(host='localhost', db='test', user='root', passwd='admin' ) cur = cxn.cursor() In main.py ## import object from file from myCxn import  cur, cxn cxn2 = cur.connection # pass the connection object from cursor # cxn2.close() # close() will cause cur.execute() fail... ## before execute() print "before execute():" print "description:", cur.description print "lastrowid:", cur.lastrowid # lastrowid => The id of last modified row. print "rowcount:", cur.rowcount cur.setoutputsizes(2) # seems not work, Does nothing, required by DB API. cur.execute("select * from test.t;") for data in cur.fetchall():   print("cur1_fetchall.rownumber:", cur.rownumber)   print("cur1_fetchall.rowrowcount:", cur.rowcount)   print(data[0])   cur.execute("select * from test.t;") for data in cur.fetchall():   print("cur2_fet...

A sample MySQL build options from MySQL Performance Blog : # ./configure '--localstatedir=/var/db/mysql' '--without-debug' '--without-readline' '--without-libedit' '--without-bench' '--without-extra-tools' '--with-libwrap' '--with-mysqlfs' '--with-low-memory' '--with-comment=FreeBSD port: mysql-client-5.0.67_1' '--enable-thread-safe-client' '--with-charset=cp1251' '--with-collation=cp1251_general_ci' '--with-extra-charset=all' '--with-named-thread-libs=-pthread' '--without-server' '--prefix=/usr/local' '--mandir=/usr/local/man' '--infodir=/usr/local/info/' '--build=amd64-portbld-freebsd7.0' 'CC=cc' 'CFLAGS=-O2 -mmmx -msse -msse2 -msse3 -pipe -march=nocona  -fno-strict-aliasing' 'CXXFLAGS=-O2 -mmmx -msse -msse2 -msse3 -pipe -march=nocona -fno-strict-aliasing -O2 -mmmx -msse -msse2 -msse3 -p...

Just following the steps to install Django on CentOS 5.4 # yum install subversion # cd $APACHE_HOME # mkdir django-src # cd django-src # svn co http://code.djangoproject.com/svn/django/trunk/ # cd trunk # python setup.py install Wish this helps. regards, Stanley Huang

The MySQL in Unix system, the database name and table name are case sensitive as default. But in Windows, they are case insensitive. That is because the file system in Unix are case sensitive but in Windows is not. So, the easy way to solve the problem or for compatibility between different platform, you can choose the case sensitive or not in your MySQL database. The way to setting it is the by the option "low-case-table-name", and there are three values (0,1,2) for this option. 0: Table and database names are stored on disk using the lettercase specified as DDL statement. 1: Table names are stored in lowercase on disk and name comparisons are not case sensitive. 2: Table and database names are stored on disk using the lettercase specified as DDL statement, but MySQL converts them to lowercase on lookup. Wish this helps. regards, Stanley Huang

Because I have multi MySQL environments, so I have to assign different parameter (especially the "--socket" option) in different environment, and it make me crazy. So I create a folder "/shell" for store my scripts and create a alias "mysql" to the script in /shell. My sample as the following: .bashrc: # cat ~/.bashrc | tail -3 export MYSQL_HOME=/usr/local/mysql/5.1 export PATH=$PATH:$MYSQL_HOME/bin alias mysql="/shell/mysql" Script /shell/mysql:   #!/bin/bash -vx echo "call $0..." sMySQLCmdList="/usr/mysql/bin/mysql /usr/local/mysql/bin/mysql" #sMySQLCmd="" for sItem in $sMySQLCmdList do   if [ -f $sItem ]   then     sMySQLCmd=$sItem     break   fi done if pgrep mysqld then   mysql_socket=`ps -ef | grep mysqld | grep -v monitor | grep socket | sed -e 's/.*--socket=//' |     cut -d' ' -f1`     if [ `echo $@ | grep -c -- -h` -eq 1 ]   then     $sMySQLCmd $@   elif [ ! -z $mys...

Sometimes, we will use partitioning to split the data into different files. But how do we backup the data by the command mysqldump? The same as the following: Create table and insert data: mysql> create table test.tr1 (     ->   id int     -> ) engine = InnoDB     ->   partition by range (id)     ->   (     ->     partition p0 values less than (10),     ->     partition p1 values less than (20),     ->     partition pm values less than (maxvalue)     ->   ); Query OK, 0 rows affected (0.17 sec) mysql> insert into test.tr1 values (1),(2),(11),(12),(21),(22); Query OK, 6 rows affected (0.30 sec) Records: 6  Duplicates: 0  Warnings: 0 Dump data and list files: # mysqldump --user=root --password=password --no-creat...

Memcaced is a good solution for scale out your system. And there is a project for MySQL udf by implement memcached. Prepare libmemcached: # wget http://download.tangent.org/libmemcached-0.37.tar.gz # export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig # ./configure --with-mysql=/usr/local/mysql/bin/mysql_config # make && make install PS. when I use libmemcached 0.38 and complie source, I get a error like below: # wget http://download.tangent.org/memcached_functions_mysql-0.8.tar.gz servers.c: In function 'memc_servers_set': servers.c:122: error: 'memcached_st' has no member named 'hosts' servers.c:123: error: 'memcached_st' has no member named 'hosts' servers.c:124: error: 'memcached_st' has no member named 'hosts' But after down-grade the version from 0.38 to 0.37 then works. Compile memcahced function: # wget http://download.tangent.org/memcached_functions_mysql-0.8.tar.gz # tar zxvf ./ memcached_functions_mysql-...

Three processes to get process info: 1. show all process: mysq> show processlist; +----+------+-----------------+------+---------+------+-------+------------------+ | Id | User | Host            | db   | Command | Time | State | Info             | +----+------+-----------------+------+---------+------+-------+------------------+ |  1 | root | localhost: 47605 | NULL | Sleep   |   27 |       | NULL             | | 16 | root | localhost       | test | Query   |    0 | NULL  | show processlist | +----+------+-----------------+------+---------+------+-------+------------------+ 2 rows in set (0.00 sec) 2. get process that use port 47605 : mysql> \! netstat -ntp | grep 47605 tcp...

Prepare the package first for build the memcached storage engine. Download libmemacached 0.34 and install: # wget http://download.tangent.org/libmemcached-0.34.tar.gz # tar zxvf ./libmemcached-0.34.tar.gz # cd ./libmemcached-0.34 # export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig # ./configure && make && make install Download libxml2 and install: # wget ftp://xmlsoft.org/libxml2/libxml2-2.7.7.tar.gz # tar zxvf libxml2-2.7.7.tar.gz # cd ./libxml2-2.7.7 # ./configure && make && make install Download  libxmlrow and install: # wget http://download.tangent.org/libxmlrow-0.2.tar.gz # tar zxvf ./libxmlrow-0.2.tar.gz # cd ./libxmlrow-0.2 #  export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig # ./configure && make && make install  Download  memcached storage and install: # export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig # sed -i "s#uint16_t#uint32_t#g" ./src/ha_memcache.cc # ./configure --...

Connection have such methods: 1. close() => close database connection. 2. commit() => commit transaction. 3. rollback() => rollback transaction. 4. cursor() => create curosr object and return. 5. begin() => start transaction. (deprecated, and will be removed from 1.3) The sample code for connection/cursor testing: Ex1: #/usr/bin/python import MySQLdb cxn = MySQLdb.connect(host='localhost', db='test', user='root', passwd='admin123' ) ## create cursor cur = cxn.cursor() ## query from database #cur.query(" select * from test.t limit 5; ") ## no query attribute for cursor cur.execute(" select * from test.t limit 5; ") for data in cur.fetchall():   #print(data[0],data[1],data[2])   print(data[0],data[1]) cur.close() cxn.close() Ex2: #/usr/bin/python import MySQLdb cxn = MySQLdb.connect(host='localhost', db='test', user='root', passwd='admin123' ) cur = cxn.cursor() ...

If you want to get some information about MySQLdb API, you can use the following script to get the info. #!/usr/bin/python try:   import MySQLdb   db = MySQLdb   if db:     print "db.apilevel=" + db.apilevel     print "db.threadsafety=" + str(db.threadsafety)     print "db.paramstyle=" + db.paramstyle except ImportError:   print "import MySQLdb fail"   exit The attributes description: a. apilevel => Version of API. b. threadsafety => Level of thread safety     0: Not threadsafe. Should not share the module at all.     1: Minimally threadsafe. Could share module but not connection. ( Default )     2: Moderately threadsafe. Could share both module and connection but not cursors.     3: Fully threadsafe. Could share module, connection and cursor. c. paramstyle => Parameter style of the module     numeric: WHERE addr=:...

Use pkg command to install Django: # pfexec pkg set-authority -O http://pkg.opensolaris.org/webstack  # webstackpfexec pkg refresh  Launch Pkg Manager by downloading. # firefox http://pkg.opensolaris.org/webstack [search "Django"] [click "install"] Wish this helps. regards, Stanley Huang