为SQL Server数据库创建用户并通过C＃.net应用程序访问

Question

I have created the users for SQL Server database. It got created just fine.

My problem is when I am accessing through application by executing the following code it does not switch to that user which I am specify as

exec as user='myuser'
ALTER USER myuser WITH DEFAULT_SCHEMA=maindb
EXEC sp_addrolemember N'db_owner', N'myuser'

and I have run the query as

DbCommand command = ds.CreateCommand();
command.CommandText = "exec as user='myuser'";
command.CommandType = CommandType.Text;
command.ExecuteNonQuery();

from C# code

Waiting for your valuable responses and comments

Answer 1

yes, this is expected. the connection string contains the credentials required to connect to the server. and typically there is a single connection string between the application and database to optimize resources and take advantage of connection pooling etc.

different users may have different rights in the system, but that can be handled by authorization, not connection strings.

Answer 2

EXECUTE AS Clause

The user or login name specified in EXECUTE AS clause must exist as a principal in sys.database_principals or sys.server_principals, respectively, or else the create or alter module operation fails. Additionally, the user that creates or alters the module must have IMPERSONATE permissions on the principal.

Do you satisfy those conditions?