Question

I use Enterprise Library and I have one problem:

string sql = " 
               UPDATE StackOverflow SET UserName = @UserName
               WHERE Id = @Id 
             ";

DbCommand cmd = base.Database.GetSqlStringCommand(sql);

base.Database.AddInParameter(cmd, "Id", DbType.Int32, StackOverflow.Id);
base.Database.AddInParameter(cmd, "UserName", DbType.Int32, StackOverflow.UserName);

int val = Convert.ToInt32(base.Database.ExecuteScalar(cmd));

Convert.ToInt32(base.Database.ExecuteScalar(cmd)) //returns 0.

I’ve read this article http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.executescalar.aspx

The article says:
The function returns the new Identity column value if a new row was inserted, 0 on failure.

but I did not insert into that table – I only want to update and return updated row Id.

Answer 1

You should use ExecuteNonQuery in your case.

ExecuteScalar

Executes the query, and returns the first column of the first row in the result set returned by the query

ExecuteNonQuery

Executes a Transact-SQL statement against the connection and returns the number of rows affected

Your query doesn’t return anything, so ExecuteScalar is not the right method to work with.
ExecuteNonQuery on the other side will give the correct information if your query has updated anything.