How can I get the detail format of video? - C# Discussion Boards

25-Jul-05 19:16

Set the IDs of the checkboxes as you create them, or in databinding, or something.

Christian Graus - Microsoft MVP - C++

odbc .net help

binglin25-Jul-05 17:29

binglin

25-Jul-05 17:29

Hi,

i'm trying to get my C# application to connect to a database which is located in another computer.

what are the steps required to make it function?

i have installed odbc .net data provider and i've tried using this connection string:

myConnectionString = "DRIVER={SQL Server};SERVER=localhost;UID=rfid; Trusted_connection=true;DATABASE=rfid;";

but it gives me a error of access denied or server doesn't exist, i'm not so clear about this, thus i hope to know what are all the steps required for both the client and server to do inorder to make this work

thanks!
-----------------------------------------------
BingLin

Craig G Fraser25-Jul-05 21:20

Craig G Fraser

25-Jul-05 21:20

Try changing your SERVER name from localhost to the actual name of the server machine. To get the machine name, right click on "My Computer" and select properties. Select the "Computer Name" tab and you will see the "Full Computer Name".

Hope this helps

Craig

binglin25-Jul-05 22:55

binglin

25-Jul-05 22:55

i've tried connecting to a database in my own computer first, and this is my codes for the connection to test:

string myInsertQuery = "INSERT INTO test (id) Values(4)";

myConnectionString = "DRIVER={SQL Server};SERVER=localhost;UID=root; PWD=wq;Trusted_connection=true;DATABASE=rfid;";

OdbcConnection myConn = new OdbcConnection(myConnectionString);
OdbcCommand myOdbcCommand = new OdbcCommand(myInsertQuery);
myOdbcCommand.Connection = myConn;
myConn.Open();
myOdbcCommand.ExecuteNonQuery();
myConn.Close();

my userid is root, password is wq and database name is rfid, but still it gives me back a result of server doesn't exist or access is denied. is there anything wrong?

Craig G Fraser25-Jul-05 23:28

Craig G Fraser

25-Jul-05 23:28

Are you using SQL Server database ?

If you are using SQL Server then you should use SqlConnection and SqlCommnad as follows.

string myInsertQuery = "INSERT INTO test (id) Values(4)";

myConnectionString = "Initial Catalog=rfid;Data Source=localhost;UID=root;PWD=wq"

//Build a SQL Connection
SqlConnection myConn = new SqlConnection(myConnectionString);
//Create a command
SqlCommand cmd = new SqlCommand(myInsertQuery,myConn);

myConn.Open();
cmd.ExecuteNonQuery();
myConn.Close();
myConn.Dispose();

binglin26-Jul-05 15:13

binglin

26-Jul-05 15:13

i tried using the connection string u gave, but it gave me an error:

Data source name not found and no default driver specified

i'm using mySQL server 4.1, and sharpdevelop for my application

my database is in C:\Program Files\MySQL\MySQL Server 4.1\data\rfid

i can't find the error, is there any places with sample programs which i may refer to?

Should I trust the compiler to optimise?

Craig G Fraser26-Jul-05 20:22

Craig G Fraser

26-Jul-05 20:22

I havent used MySQL before but mayeb these articles will help or at least point you in the right direction:

http://www.codeproject.com/cs/database/AbdMySqlSchema.asp[^]

http://www.pcquest.com/content/linux/handson/102031401.asp[^]

javaman5925-Jul-05 17:24

javaman59

25-Jul-05 17:24

I have a bit of code which declares local variables in a loop, to perform intermediate calculations.

The issue is: the local variable declarations came naturally, as the thought process in designing the loop, but they could be criticised for putting 2 variables on the stack with each loop iteration, so, in the interests of efficiency, they should be declared outside the loop. However, I wonder if it would be better to leave the natural sequence, and trust the compiler to optimise.

The section of code is similar too...

// Global variables

System.DateTime startTime = System.DateTime.Now;
int step = 0;

// Display a count of seconds..0, 1, 2..etc..
while (true)
{
	// Calculate the time since we started.
	System.DateTime now = System.DateTime.Now;  // ? declare outside loop,
	System.TimeSpan span = now - startTime;     // ? to save stack allocation

	// if a second has elapsed since last step, then
	// step up.
	if (span.TotalMilliseconds >= step * 1000)
	{
		System.Console.WriteLine("Tick {0}",step);
		step++;
	}
}

Stephen Hosking

Christian Graus25-Jul-05 17:45

25-Jul-05 17:45

I'd do it right myself, and then not have to worry. And I wouldn't bother to declare a variable called 'now'.

Christian Graus - Microsoft MVP - C++

javaman5925-Jul-05 17:52

javaman59

25-Jul-05 17:52

>> And I wouldn't bother to declare a variable called 'now'.

lol! Quite right. The example was slightly contrived from the original, where the variable was justified, because it was used in several places.

Smile | :)

EssOEss25-Jul-05 20:15

EssOEss

25-Jul-05 20:15

I absolutely would never do this kind of optimization.
Yes, always trust the compiler. Only optimize algorithms - that's the way I do it and it saves quite a bit of worrying Smile | :)

Efficient way to number x-y Axes?

Guffa26-Jul-05 3:26

Guffa

26-Jul-05 3:26

The stack frame does not change when you declare variables. The stack frame is created when the method is called, and allocates space for all variables used in the method.

The only difference if you move the declaration is that the scope of the variables change. The space for the variables is still allocated the same way.

I always keep the declaration of the variables separate from the code. This is a practice that I got from Pascal programming. (In Pascal the variable declaration is even placed outside the actual procedure body.) I think that it makes the code clearer, and it actually more closely resembles what is actually happening when the code is executed.

---
b { font-weight: normal; }

...---...25-Jul-05 13:27

...---...

25-Jul-05 13:27

I have drawn a Rectangle and corresponding X and Y axes with tick marks.
I would now like to number the tick marks on each tick in the range of
-9 to +9. Not sure of an efficient way to attack the problem. Any ideas?

many thanks...;)

Re: Efficient way to number x-y Axes?

Christian Graus25-Jul-05 16:18

25-Jul-05 16:18

A forloop and DrawString, I would have thought...

Christian Graus - Microsoft MVP - C++

DAL or no DAL

Tom Wright25-Jul-05 12:40

Tom Wright

25-Jul-05 12:40

I'm writting an app that I hope to sell and develope into an enterprise type app. It came to my attention that I should have all my data access in a DAL along with my business objects. So my question is at what point is it necessary to implement a DAL and business object layer as to just writting a class for data access and keeping your business objects in your main app class?

Thanks

Tom Wright
tawright915@yahoo.com

Re: DAL or no DAL

Christian Graus25-Jul-05 16:19