Solution
In your SQL query that you use for comparing with the system date/time, use the convert_tz function in MySQL, using the appropriate local time zone (ie Europe/London):
convert_tz(sysdate(),'SYSTEM','Europe/London')

Mysql::Error: Got error 28 from storage engine

in your console.

Solution
It turns out that this specific error is a MySQL error, indicating that you have run out of space in the partition that the MySQL server stores its files (/var/lib/mysql).
Looking at the folder there, you can see a very large file called ibdata1.
This file holds all the information about your InnoDB tables and transactions in your MySQL. According to other posts after a Google search, it seems that this file cannot be reduced in size either by removing/truncating your tables or deleting databases that you don’t need. There are quite a few solutions out there if you really need to keep a backup of your databases, but if you only using your database for development and you DON’T NEED (!!) your data or tables, you can move this big ibdata1 to another partition for backup and restart your mysql, that will create a new file.

Solution
Change the find method to use the BINARY keyword in your database (only used with MySQL), as in the following:
u=User.find(:first, :conditions => ["BINARY login = ?", login])

Solution
To install the tools in Mandriva 2010 run:
sudo urpmi mysql-query-browser mysql-administrator.

Solution
In the page_name.json.erb file in the fields that has carriage returns make sure that you use to_json method as in the example below:

‘<%=fg_escape event.comments.to_json -%>‘,

ERROR:  Error installing mysql:
ERROR: Failed to build gem native extension...
checking for mysql_query() in -lmysclient... no ....

Solution
After searching in google, with solutions about providing different options (– –with-mysql-config, ..etc), even trying different combinations for providing the client library path, the configuration file, or the header file path, was still faced with the same error installing the mysql gem.
As the Mandriva installation was quite new, it turns out to be a couple of missing packages.
So try:

urpmi gcc
urpmi make

and run:

gem install mysql

again.

It should work out ok install the gem and output:

Building native extensions. This could take a while...
Successfully installed mysql-2.7
1 gem installed

Solution

1. Use mysql to export the data from the first table in a csv file, selecting only the common fields.
   We use the /tmp folder on the server to make sure we have the right permissions to create the file:

   mysql>SELECT common_field1, common_field2, ...
   INTO OUTFILE '/tmp/first_table.txt'
   FIELDS TERMINATED BY ','
   OPTIONALLY ENCLOSED BY '"'
   LINES TERMINATED BY '\n'
   FROM table1;

2. If the tables are in different databases remember to switch db:

   use seconddb;

   Export the second table in the second file:

   mysql>SELECT common_field1, common_field2, ...
   INTO OUTFILE '/tmp/second_table.txt'
   FIELDS TERMINATED BY ','
   OPTIONALLY ENCLOSED BY '"'
   LINES TERMINATED BY '\n'
   FROM table2;

3. now use the diff. You can use any of the following options:
   • diff -q first_table.txt second_table.txt
   • diff first_table.txt second_table.txt > diff.txt

Solution
Download the px tools from here.

Follow the instructions, in the INSTALL file after you untar the file.
You should have to do the usual three step linux installation:

configure
make
sudo make install

Afterwards to make sure that the .db file is a paradox file run:

pxinfo -f  path/to/paradox/db/file.db

The program should read the header and report back with something along the lines:

File-Version: Paradox 7.x
Filetype: indexed .DB
....

To export each Paradox db file to an sql statement run the following:

pxsqldump -d mysql -f path/to/paradox/file.db > path/to/mysql/exported/file.sql

In the example below the model is number and the file_column is intro.

1. In models/number.rb add:

file_column :intro

2. in controllers/numbers_controller.rb, make sure we have:

config.create.multipart = true
config.update.multipart = true

3. in helpers/numbers_helper.rb add:

def intro_form_column(record, input name)
  file_column_field 'record', :intro
end

def intro_column(record)
  record.intro ? link_to(File.basename(record.intro),
    url_for_file_column(record,'intro'), :popup => true) : "-"
end

4. in views/numbers/_intro_form_column.rhtml add:

  File to upload
  <%= file_column_field  'record', 'intro' %>

User.find(:all,  rder => 'rand()')