Change record status: 
Project: 
Introduced in branch: 
7.x
Introduced in version: 
7.0
Description: 

When using varchar for storage, your code must truncate values to the maximum length before they are sent to the database layer if there is any chance the data may exceed the allowed size.

In Drupal 6, MySQL and older versions of PostgreSQL would silently truncate these values. Drupal 7 runs MySQL in strict mode and includes support for more database types. Instead of truncating, it will throw a PDO Exception if attempting to write data exceeding the maximum length of the varchar.

In some circumstances it may be better to increase the size of the varchar or change the type of the column to text. However note that, on MySQL, text columns can negatively affect performance if they are included in a query that creates a temporary table.

Note that varchar columns up to 4,000 characters are supported by every database server that Drupal supports (including Microsoft SQL Server and Oracle).

Impacts: 
Module developers
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done