title: Map string to guid with Dapper
body: <p>I'm using Dapper to hammer out some load testing tools that need to access a PostgreSQL database. This particular version of PostgreSQL does not support GUIDs natively, so GUID values are stored as 32 character strings. The values are converted to strings using <code>someGuid.ToString("N")</code>, conversion back to Guid can be done using <code>new Guid(stringValueFromColumn)</code>.</p>
  
  <p>My question is how do I get Dapper to read the strings and convert them back to Guids?</p>
  
  <p>I tried modifying the DbType mapping but that doesn't work.</p>