What is a GUID

For those of you who don't know, a GUID (pronounced goo'id - Globally unique identifier) is a 128-bit integer that can be used to uniquely identify something. You may store users or products in your database and you want somehow uniquely identify each row in the database. A common approach is to create a autoincrementing integer, another way would be to create a GUID for your products.

How to create a GUID in C#

The GUID method can be found in the System namespace. The GUID method System.Guid.NewGuid() initializes a new instance of the GUID class.

There are also a few overloads available for those of you who want the GUID formatted in a particular fashion.

The following live sample will output the GUID generated, the source code is also below.

Response.Write(@"<br>System.Guid.NewGuid().ToString() = " + System.Guid.NewGuid().ToString());
   Response.Write(@"<br>System.Guid.NewGuid().ToString(""N"") = " + System.Guid.NewGuid().ToString("N"));
   Response.Write(@"<br>System.Guid.NewGuid().ToString(""D"") = " + System.Guid.NewGuid().ToString("D"));
   Response.Write(@"<br>System.Guid.NewGuid().ToString(""B"") = " + System.Guid.NewGuid().ToString("B"));
   Response.Write(@"<br>System.Guid.NewGuid().ToString(""P"") = " + System.Guid.NewGuid().ToString("P"));