I realize that this question already has an accepted answer, but I thought it would be useful to share some information about formatting guids. The ToString() (no parameters) method formats a guid using this format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx The ToString(string format) method formats a guid in one of several ways: “N” – xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx (32 digits) “D” – … Read more
If you already have a string representation of the Guid, you can do this: Guid g = new Guid(“11223344-5566-7788-99AA-BBCCDDEEFF00”); And if you want a brand new Guid then just do Guid g = Guid.NewGuid();
A big reason for a clustered index is when you often want to retrieve rows for a range of values for a given column. Because the data is physically arranged in that order, the rows can be extracted very efficiently. Something like a GUID, while excellent for a primary key, could be positively detrimental to … Read more
Is there a way to set my property as null or string.empty in order to restablish the field in the database as null. No. Because it’s non-nullable. If you want it to be nullable, you have to use Nullable<Guid> – if you didn’t, there’d be no point in having Nullable<T> to start with. You’ve got … Read more
First off, this is a really good idea. A brief aside: I wish C# made it easier to create cheap typed wrappers around integers, strings, ids, and so on. We are very “string happy” and “integer happy” as programmers; lots of things are represented as strings and integers which could have more information tracked in … Read more
Having [assembly: ComVisible(false)] and [assembly: Guid(“…”)] at the same time makes perfect sense in certain cases. You start with an empty assembly and will perhaps want to expose something from it to COM. So you mark the assembly as not ComVisible and later mark the entities to expose as ComVisible. That is why the GUID … Read more
Try this: Guid ownerIdGuid = Guid.Empty; try { string ownerId = CallContextData.Current.Principal.Identity.UserId.ToString(); ownerIdGuid = new Guid(ownerId); } catch { // implement catch }
java.util.UUID.randomUUID();
Kimberley Tripp (SQLSkills.com) has an article on using GUID’s as primary keys. She advices against it because of the unnecessary overhead.
Use the uniqueidentifier data type which is designed for GUIDsFor example, they will sort like GUIDs should Create a UNIQUE index on it (more flexible than a unique constraint Note, these are 2 separate steps