Stored procedure does not create new table - asp.net

Question

I am trying to create tables dynamically in a SQL Server database.
Like this with input from a textbox:
ALTER PROCEDURE [dbo].[opretNyEsyn]
#Navn NVARCHAR(100)
AS
BEGIN
DECLARE #SQLString NVARCHAR(MAX)
SET #SQLString = 'create table ' + QUOTENAME(#Navn) +
'([EsynNummer][int]Identity(1,1),
[Dato][datetime])'
END
But nothing happens when I run the method from the form, the table isn't created, and I get no errors.
What am I missing?
Notice. This is just a test table. It isn't supposed to look like this in the end.
Thanks in advance

Answer 1

You are just creating the statement, but in order to create the tables, you need to Execute the statement using the EXEC statement of sp_executesql SP. Add an execute statement to your Procedure. Like this
ALTER PROCEDURE [dbo].[opretNyEsyn]
#Navn nvarchar(100)
as
Begin
declare #SQLString nvarchar(max)
set #SQLString = 'create table ' + QUOTENAME(#Navn)+
'([EsynNummer][int]Identity(1,1),
[Dato][datetime])'
exec(#SQLString)-- Execute the Statement
End
Go

Answer 2

You need to execute dynamic SQL:
ALTER PROCEDURE [dbo].[opretNyEsyn]
#Navn SYSNAME
as
Begin
declare #SQLString nvarchar(max);
set #SQLString = 'create table ' + QUOTENAME(#Navn)+
'([EsynNummer][int]Identity(1,1),
[Dato][datetime])';
EXECUTE (#SQLString);
End;
Anyway I recommend to read The Curse and Blessings of Dynamic SQL and Packaging Permissions in Stored Procedures:
CREATE TABLE #tbl
The desire here is to create a table of which the name is determined at run-time.
If we just look at the arguments against using dynamic SQL in stored procedures, few of them are really applicable here. If a stored procedure has a static CREATE TABLE in it, the user who runs the procedure must have permissions to create tables, so dynamic SQL will not change anything. Plan caching obviously has nothing to do with it. Etc.
Nevertheless: Why? Why would you want to do this? If you are creating tables on the fly in your application, you have missed some fundamentals about database design. In a relational database, the set of tables and columns are supposed to be constant. They may change with the installation of new versions, but not during run-time.