How to pass a sql connections string value to a C# program

Question

I am very new to programming world (sorry if this question has been answered many times, at least i didnt get any clue from searching the internet), and i am trying to build a C sharp app recently. This exe will be called in another program, and upon calling, the program will pass a sql connection string value the c sharp exe app. My question is how to make the app receive the value.

the connection string should look like

“Provider=SQLOLEDB.1;Password=xxxxxxxx;Persist Security Info=True;User
ID=xxxxxxxx;Initial Catalog=ATTACH;Data Source=LNGSEAL136504A;
Use Procedure for Prepare=1;Auto Translate=True;Packet Size=4096;Workstation 
ID=LNGSEAL136504A;Use Encryption for Data=False;Tag with column collation when 
possible=False”

What I wrote : Here is my code: class Program { static void Main(string[] args) { Console.WriteLine("its running!"); Console.ReadKey(); try {

            int Len;
            string cnn = null;
            Len = args.Length;
            for (int i = 0; i < args.Length; i++)
            {
                cnn = cnn + " " + args[i];
            }
            Console.WriteLine(cnn);
            Console.WriteLine(Len);               

            Console.ReadKey();

            ADODB.Connection mycnn = new ADODB.Connection();
            mycnn.Open(cnn);
            ADODB.Recordset rs = new ADODB.Recordset();
            rs.Open("sql statements", mycnn);



            mycnn.Close();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
            Console.ReadKey();
        }
    }
}

but it throws me a "unable to cast a com object error". Any idea? Please advise.

[Solved]

I used oledbconnection instead of adodb, and it works with no problem. Thanks for everyone who helped.

Not to overwhelm you with questions, but it depends greatly on what type of program it is. Is the C# app a Console application (looks like a DOS/Command window), WinForms, ASP.NET, Silverlight, WPF, Windows Service exposing a WCF interface? — David
– David, Commented May 17, 2012 at 20:33
So do you have two process, and you are looking for methods of interprocess communication, or does the one program start the other, or what? It's not really clear what you are looking for. Also, why would someone who is new to programming start with a project that involves (at least) two processes and a database? Can't you start with something easier until you understand the basics? You probably don't need two processes for whatever you are trying to do, but without knowing more about what you are doign, it's hard to make any concrete suggestions. — Mark Byers
– Mark Byers, Commented May 17, 2012 at 20:34
Thanks for you quick help. I am trying to write a console app. — John
– John, Commented May 17, 2012 at 20:35
Mark, The program that passes the connection string is a full blown software developed by a big company. This program is used to manipulate our company's sql databases with a front end user interface. This program offers a feature that you can run your own exe or vbscript to do auto batch updates in sql by passing the connection string to the current database. I am just trying to write an exe to get it working.. — John
– John, Commented May 17, 2012 at 20:41
@John: Maybe it would be a good idea to ask that company to provide some documentation. The answer so far (reading the command line parameters) is a good guess, but it's just a guess - there are several other ways to pass data between applications. The people that know what is actually being done are the people who wrote the original application. (If you have the source code you can look yourself how the connection string is being passed, assuming you can understand the code). — Mark Byers
– Mark Byers, Commented May 17, 2012 at 21:04

Cᴏʀʏ · Accepted Answer · 2012-05-17 20:39:23Z

5

You can pass the connection string via command line arguments (using whichever technique the source application uses to invoke an executable), and then you can retrieve them from the args array in the Main(string[] args) function of your receiving executable.

For example, on the receiving end:

class TestClass
{
    static void Main(string[] args)
    {
        // avoiding empty/null checks for simplicity
        string connectionString = args[n]; // where "n" is index value of your
                                           // connection string argument

        DoWork(connectionString);
    }
}

With that in mind, there might be better ways to accomplish what you're asking. If you described your project to us with a little more detail we may be able to provide alternate suggestions.

edited May 17, 2012 at 20:39

answered May 17, 2012 at 20:34

Cᴏʀʏ

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3 Comments

John Over a year ago

Cory's way actually works, but now I ran into another problem. Since the parent program can support exe or vbscript, I tried vbscript which works find. For vbscript, wscript.argument(0) picks the full connection string, but when I am using c sharp to write my app; the c sharp typical method static void Main(string[] args) in which args[0] only picks the first two "Provider=SQLOLEDB.1;Password=law32sql", and args[1] picks the next one and on…I do not know if there is a way to let c sharp app pick the full connection string? I appreciate if you guys could help me on this.

Cᴏʀʏ Over a year ago

@John: You probably need to make sure you have your argument surrounded with quotation marks (and not the angled quotation marks you have in your question), otherwise it will get split on spaces into the buckets of the args array.

John Over a year ago

I fixed the connection string part, but it throws me a "unable to cast a COM object type of" error.

EdChum · Accepted Answer · 2012-07-05 21:58:32Z

0

it is very easy in c#

in sender application by using Process.start("your exe path which you want send Connection string to it","connection string ");

in reciver application and in your exe in main method (founded in program class)

main(string[] args)

args[0] will hold the connection string sended by other program.

try ..

edited Jul 5, 2012 at 21:58

EdChum

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answered May 17, 2012 at 20:42

Mohammad Soliman

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2 Comments

John Over a year ago

But the args[0] seems to only hold the part of the connection string not the whole string..actually the complete connection sting is broken into parts held by an array of args[n]

Mohammad Soliman Over a year ago

it depends in the way of sendig connectio string to application sen it as full string and in reciver app create connection object from the string

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