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Is storing a delimited list in a database column really that bad?
Imagine a web form with a set of check boxes (any or all of them can be selected). I chose to save them in a comma separated list of values stored in one column of the database table.
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How do I enlarge an EER Diagram in MySQL Workbench?
I am working on a moderately complex schema in MySQL Workbench, and the single page of the EER diagram is now full up. Does anyone know how to enlarge it to two or more pages?
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What are the most interesting equivalences arising from the Curry-Howard Isomorphism?
...ot reflected in expressions)
intersection types | implicit conjunction
union types | implicit disjunction
open code | temporal next
closed code | necessity
effects | possibility
reachable state | possible world
monadic metalanguage | lax...
How to get last N records with activerecord?
...e-wise - at least not up to Rails 3.1. SomeModel.last(5) will execute the select statement without a limit, returning all records of SomeModel to Ruby as an array, after which Ruby will pick out the last (5) elements. Efficiency-wise, currently, you want to use limit - particularly if you have pote...
Is there a way to get a collection of all the Models in your Rails app?
....
EDIT: Just for fun, I found a way to list all classes
Module.constants.select { |c| (eval c).is_a? Class }
EDIT: Finally succeeded in listing all models without looking at directories
Module.constants.select do |constant_name|
constant = eval constant_name
if not constant.nil? and constan...
List all sequences in a Postgres db 8.1 with SQL
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The following query gives names of all sequences.
SELECT c.relname FROM pg_class c WHERE c.relkind = 'S';
Typically a sequence is named as ${table}_id_seq. Simple regex pattern matching will give you the table name.
To get last value of a sequence use the following query:...
写出高质量代码的10个Tips - 更多技术 - 清泛网 - 专注C/C++及内核技术
写出高质量代码的10个Tips很长一段时间以来，我都在关注如何提高代码质量，也为此做过一些尝试，我想这个话题可能大家会比较感兴趣，在这里分享一下我关于如何提高代...很长一段时间以来，我都在关注如何提高代码质量，...
How do I use a file grep comparison inside a bash if/else statement?
...m grep --help, but also see man grep:
Exit status is 0 if any line was selected, 1 otherwise;
if any error occurs and -q was not given, the exit status is 2.
if grep --quiet MYSQL_ROLE=master /etc/aws/hosts.conf; then
echo exists
else
echo not found
fi
You may want to use a more specif...
What is the equivalent of 'describe table' in SQL Server?
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use Select * From INFORMATION_SCHEMA.COLUMNS Where TABLE_NAME = 'TABLENAME' if you don't want to use a stored procedure
– Matias Elorriaga
Aug 4 '14 at 18:21
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【解决】mysql_real_connect: Can\'t connect to local MySQL server throu...
【解决】mysql_real_connect: Can't connect to local MySQL server through socket '/tmp/mysql.sock'cant-connect-to-local-mysql-server-through-socket-tmp-mysql-sockmysql_real_connect: Can& 39;t connect to local MySQL server through socket & 39; tmp mysql sock& 39;解决方法（挨个试）：1、ln...