Jack @ ASP.NET

In my last post Call SQLCMD to run SQL script via C#, we know how to call SQLCMD via C#. But in most scenarios, we also need the exit code(%ErrorLevel%) or the sub SQLCMD thread. It is simple, use ‘-b’ in sqlcmd can do this!

So, just add a –b parameter when call the SQLCMD!

Here are more parameters in error reporting,

Usually, we need to call some sql script to update our database in our application(C#), and it is a good way to call SQLCMD to execute the sql scripts. One important reason is that our scripts always contains the GO statement which is is not a Transact-SQL statement; it is a command recognized by the sqlcmd and osql utilities and SQL Server Management Studio Code editor. Since the SQLCMD and SQL Server Management Studio will do the same thing, the scripts edited by SQL Server Management Studio will be 100% supported by SQLCMD.

Here is a block of code to call SQLCMD:

string tmpFile = Path.GetTempFileName();

string argument = string.Format(@" -S {0} -d {1} -i ""{2}"" -o ""{3}""",
    ServerName, DatabaseName, fileName, tmpFile);

// append user/password if not use integrated security
if (!connection.IsIntegratedSecurity)
    argument += string.Format(" -U {0} -P {1}", User, Password);

var process = Process.Start("sqlcmd.exe", argument);
process.StartInfo.UseShellExecute = false;
process.StartInfo.CreateNoWindow = true;
process.Start();
while (true)
{
    // wait for the process exits. The WaitForExit() method doesn't work
    if (process.HasExited)
        break;
    Thread.Sleep(500);
}

Some members of the C# community were discussing optional parameters and the implications for future versions when optional parameter values change.  In short, you need to realize that changing the value of optional parameters in a public API is a change that is observable at client code. The ramifications vary greatly, from “no big” to “stop the world”. I’ll give a brief explanation of how the feature works, and what you need to watch for and how to separate reasonable caution from irrational fear from using a feature.

While most modern programming languages provide some way of declaring optional function parameters, C# doesn’t provide a way of directly doing so, despite the fact that VB.NET and .NET’s attribute system both support this functionality. This is a subject of some debate currently in the C# community. The C# development team’s position seems to boil down to the following: When provided, this feature is usually nothing more than dressing up method overloading with a little syntactic sugar.

When you get right down to it, their position makes some sense. A function with an optional parameter is in reality two different functions: one that assumes some default behavior if the optional parameter is omitted, and another that performs more specific behavior based on the value of the optional parameter if provided. But that doesn’t change the fact that using overloaded methods to provide optional parameter support feels a little clunky. It works, but you always wind up writing more code, and you pollute your object interface with the extra method signatures required to support all of your optional parameters. Let’s look at some alternatives.

Some of the big improvements in EF4 include:

EF4 enables you to:

• Develop without ever having to open a designer or define an XML mapping file
• Define your model objects by simply writing “plain old classes” with no base classes required
• Use a “convention over configuration” approach that enables database persistence without explicitly configuring anything
• Optionally override the convention-based persistence and use a fluent code API to fully customize the persistence mapping

=== Program that converts List (C#) ===

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<string> dogs = new List<string>(); // Create new list of strings
        dogs.Add("Aigi");                       // Add string 1
        dogs.Add("Spitz");                      // 2
        dogs.Add("Mastiff");                    // 3
        dogs.Add("Finnish Spitz");              // 4
        dogs.Add("Briard");                     // 5

        string dogCsv = string.Join(",", dogs.ToArray());
        Console.WriteLine(dogCsv);
    }
}

=== Output of the program ===

Aigi,Spitz,Mastiff,Finnish Spitz,Briard