Help in using queries from MS Access in Visual C# .NET

[itsme7]

Hello,
I'm working on a little project that has to get into a database on a server. My question is: How am I supposed to use the queries I made in MS Access in my C# project? I'm talking about queries such as:

SELECT Count(*) AS IDExists
FROM tblCustomer
WHERE ID=[@ID];

How am I supposed to send parameters (such as "@ID") from my C# code into the query?
I mean, if I want to use the query as a function and put it in an if, for example: if(storedProcedureCount>0)
Please help, I'm a beginner as you see, I will appreciate it if you explain me in detail.
With thanks, itsme7

[hbxtlhx]

Hello,
I'm working on a little project that has to get into a database on a server. My question is: How am I supposed to use the queries I made in MS Access in my C# project? I'm talking about queries such as:

SELECT Count(*) AS IDExists
FROM tblCustomer
WHERE ID=[@ID];

How am I supposed to send parameters (such as "@ID") from my C# code into the query?
I mean, if I want to use the query as a function and put it in an if, for example: if(storedProcedureCount>0)
Please help, I'm a beginner as you see, I will appreciate it if you explain me in detail.
With thanks, itsme7

such as:

string queryString = "SELECT Count(1) AS IDExists FROM tblCustomer HERE ID=?";
OleDbCommand command = new OleDbCommand(queryString, connection);
command.Parameters.Add("@p1", OleDbType.Char, 3).Value = "a";
object retValue= command.ExecuteScalar();
if (retValue is int && (int)retValue>0)
{
//exists records
}
else
{
//not exists
}

[itsme7]

such as:

string queryString = "SELECT Count(1) AS IDExists FROM tblCustomer HERE ID=?";
OleDbCommand command = new OleDbCommand(queryString, connection);
command.Parameters.Add("@p1", OleDbType.Char, 3).Value = "a";
object retValue= command.ExecuteScalar();
if (retValue is int && (int)retValue>0)
{
//exists records
}
else
{
//not exists
}

Mmm OK, just a couple questions:
1. Why did you change the * in count to 1?
2. How do I manage the connections, I mean, what am I supposed to write in the code in order to make a connection?
3. Is the "a" a parameter (I mean, is it the @ID)?
4. What does the parameter OleDbType.Char and 3 mean?
5. What if I have more than 1 parameter? like in the following query:

 SELECT WasUsed
FROM tblCustomer
WHERE CPUCode=[@CPUCode];

6. Why did you put a question mark instead of [@ID]?

Oh and another thing: the Value in line command.Parameters.Add("@p1", OleDbType.Char, 3).Value = "a"; doesn't pop up when I write the code. I am using Visual Studios .NET 2003.