SQL中的uniqueidentifier在c＃中变为小写

Question

I have column(uniqueidentifier) in SQL which stored guid. I see that its in upper case. But when the data is returned through SP to C# code it becomes lower case

I am using entity framework in data access. What could be the reason and can i avoid this conversion?

Answer 1

If you using Entity Framework, uniqueidentifier data will convert to Guid.

The value of this Guid, represented as a series of lowercase hexadecimal digits in the specified format.

If you need consistency in your application you can use one format when you get string out of Guid.

Check Guid.ToString Method (String) for available formats

There can be a place where you get guid as string from database so that will be infinity upper case. ( check stored procedures Views etc..)

To avoid this issue you have to make sure that return uniqueidentifier as it is, don't convert to varchar and also follow one stranded format when converting to string.

For other operations like comparing etc..You can use Guid operators..

Answer 2

I suspect that SQL Server stores a uniqueidentifier as a 128-bit integer and then converts it to hexadecimal for display. As Alexander says, it doesn't matter whether it displays this hexadecimal value in upper-case or lower-case as they represent the same thing.

If it matters to your application, then you can convert it to upper-case in C# without a problem.