I have just install Drupal 7 through microsoft web platform installer after successful installation when i run web matrix and run it. It show me this error I am new to drupal so have no clue what is this error and how to solve it
It's a simple problem to solve, just visit install.php on your website and you should be able to install as normal. Sometimes the installer doesn't automatically redirect to install.php and instead visits the root of the site. The exception happens because Drupal looks for the database tables and they don't exist, install.php not having been run. There's a discussion here:
How to fix this problem
Go to xampp\mysql\bin
Open my.ini
Change "max_allowed_packet" from "1m" to "16m"
Save my.ini
Now restart MySql through the XAMPP control panel.
Found this solution here. http://minorpoint.blogspot.com/2007/09/mysql-server-has-gone-away.html
来源：https://stackoverflow.com/questions/7237619/pdoexception-sqlstate42s02