MySQL Error Nr 1045: Access denied ... (using password: YES)

If you opt to reinstall MySQL, the following error is probably what you'll find upon reinstalling and finishing the MySQL Instance Config Wizard:

The solution is to not only uninstall MySQL, but also remove (a) the directory where it is installed, and (b) the directory where it keeps its settings. On Windows 7, the latter can be found at C:\ProgramData\MySQL, or C:\Users\All Users\MySQL which is the same thing. Once these are removed, proceed to reinstall MySQL, doing a detailed configuration (from the MySQL Instance Config Wizard) to reset the root password. If you miss any of these steps, you might need to uninstall and reinstall again.

SQL String Concatenation in Informix, MySQL and SQL Server

Like selecting the top N rows, syntax for string concatenation is DBMS-specific. The following are examples for Informix, MySQL and SQL Server.

Informix

select name || ' ' || surname

from customer;

MySQL

select concat(name, ' ', surname)
from customer;

Note: the MySQL concat() function can accept any number of arguments.

SQL Server

select name + ' ' + surname

from customer;

SQL Top n Rows in Informix, MySQL and SQL Server

Different dialects of SQL allow you to obtain the first n rows, resulting from a query, in different ways. The following are examples in Informix, SQL Server, and MySQL. Tip: to get the last n rows, simple switch the order by clause (from ascending to descending, or vice versa).

Informix

select first 5 *

from customer;

MySQL

select *

from customer

limit 5;

SQL Server

select top 5 *

from customer;

Oracle buys Sun; Geocities to die soon; Ubuntu 9.04 released

A lot of stuff has happened this week, and keeping up to date with Slashdot is a good idea. Some highlights:

• On Monday 20th April, Oracle bought Sun Microsystems
• On Thursday 23rd April, MySQL split into two separate forks
  
• On Thursday 23rd April, Ubuntu 9.04 was released
• On Thursday 23rd April, Yahoo! announced the end of Geocities