Oho, Twitters internal IDs are moving towards 64-bit integers. So remember to update your e.g. MySQL integer columns to BIGINT.
This means that if you currently use signed 32-bit integers to track user IDs in your system, you should update your code to use 64-bit integers as soon as you can. To be safe, and to provide a date to aim for, we recommend making this change by July 1, 2013.
I just tried to uninstall MySQL on Debian via
apt-get remove --purge mysql-server
apt-get remove --purge mysql-client
and wondered that the directories /var/lib/mysql /etc/mysql still existed after the commands. Then I recognized, that a
apt-get remove --purge 'mysql-server.*'
is doing better and removes everything.
if you get a
/etc/init.d/mysql: WARNING: /etc/mysql/my.cnf cannot be read.
error when you try to re-install MySQL, try a
apt-get purge mysql-common
and try to re-install again.
Need some help to pick the right noSQL solution for your project? Then maybe Nathan Hurst’s Visual Guide to noSQL systems is a good starting point. It’s based on the requirements from Brewer’s CAP theorem (Consistency, Availability and Partition Tolerance).
Often it is useful to export a SQL query result into a file. Especially CSV files are nice for this task. The following SQL query saves the result in a file called
output.csv into the
SELECT * FROM my_table
INTO OUTFILE '/tmp/output.csv'
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY 'n';
Shame on me, that it took my brain 4 months to recognize that Apache Ibatis has retired and has become mybatis.
I just had the following problem when trying to start a Ruby on Rails application on a fresh installation of Mac OS X Snow Leopard after I installed the mysql gem via
gem install mysql:
uninitialized constant MysqlCompat::MysqlRes
I searched a bit and found a solution here. It was a problem with a buggy version of the Mysql driver. So you need to use a different version when installing the mysql gem. So first uninstall the existing gem via
gem uninstall mysql
and reinstall it via
export ARCHFLAGS="-arch i386 -arch x86_64" ;sudo gem install --no-rdoc --no-ri -v=2.7 mysql -- --with-mysql-dir=/usr/local/mysql --with-mysql-config=/usr/local/mysql/bin/mysql_config