Re: Default form in Access 2000 - Database Discussion Boards

ExtraLean4-Feb-03 5:52

4-Feb-03 5:52

(FYI: The app in question will be an ASP.NET web application interfacing a Sybase back-end.)

I'm new to the web arena and I am trying to get a feel for which one I should choose. Please share any thoughts or experiences Big Grin | :-D

Which is better... ADO.NET or ODBC.NET?

Why would someone choose one over the other?

What benefits do you get with ADO.NET?

What benefits do you get with ODBC.NET?

Any drawbacks to either one?

Thanks!
ExtraLean

--
Edward Livingston
aka. ExtraLean
--

Re: ADO.NET -vs- ODBC.NET

Bruce Duncan4-Feb-03 7:59

Bruce Duncan

4-Feb-03 7:59

ODBC.NET is a database/driver specific part of ADO.NET. Others are SqlClient for Sql Server, and OleDb for databases that have OleDb drivers available.

Preferrably you'd want to use a provider (in your case Sybase) that is specifically tailored for .NET (like the SQL one is specific for MS Sql Server)

If no such .NET specific driver is available your next best bet is an OLEDB driver and the OleDb .NET classes.

If you're still out of luck (no db specific .NET or OLEDB support), ODBC.NET is your only option. I have used ODBC.NET to access ODBC data sources with out any trouble.

To summarize (I hope), you aren't choosing between ADO.NET or ODBC.NET, but rather ODBC.NET, OleDB, or a Sybase specific .NET implementation. The best option being the last one.

Why? ODBC is older technology, and you may not be able to make full use of the available ADO.NET functionality.

Hope this helps, ( and that I didn't babble on too long Wink | ;)

)

Bruce Duncan, CP#9088, CPUA 0xA1EE, Sonork 100.10030
I can levitate birds...

Re: ADO.NET -vs- ODBC.NET

Wayne Phipps9-Feb-03 4:52

Wayne Phipps

9-Feb-03 4:52

Please excuse me for butting in but I have a question.

You stated:
"ODBC.NET is a database/driver specific part of ADO.NET. Others are SqlClient for Sql Server, and OleDb for databases that have OleDb drivers available."

Does this mean that OleDb uses COM to tonnect to the database?

Does this also mean that if you don't want to use SQL Server then then the only way is to use COM?

The reason I am asking is because I am writing an application in which I wish to use an Access database. However, if the database doesn't exist, I want to programatically re-create the database.

I have done this in the past using VB6 but as I am now using .Net have been investigating ADO.Net. The problem is that all the examples/resources I have found only demonstrate database creation using the SQL Server which I don't want to use.

Re: ADO.NET -vs- ODBC.NET

Bruce Duncan9-Feb-03 6:02

Bruce Duncan

9-Feb-03 6:02

BusterG wrote:
Does this mean that OleDb uses COM to tonnect to the database?

OleDb is COM based, if that is what you're asking. The are OleDb .NET class available, but they all ultimately talk to an underlying non .NET database driver.

BusterG wrote:
Does this also mean that if you don't want to use SQL Server then then the only way is to use COM?

No, there may be native .NET classes available for whatever data source you are using.

BusterG wrote:
I wish to use an Access database. However, if the database doesn't exist, I want to programatically re-create the database.

Firstly, I don't have any experience when it comes to coding against an Access database, so I may be talking a load of rubbish.

If I were required to use an Access db, I would first check if a .NET specific addon/driver was available and that it is stable/supported. Failing that, I would use the OleDb classes in the .NET framework (System.Data.OleDb.*) to interface with the Jet database driver.

I'm not sure how one would go about creating an Access db programmatically though.
A quick google search indicates that there is no native .NET method of doing this. So you will have to use ADOX or some other method to create an empty database.

Google Link[^]

Bruce Duncan, CP#9088, CPUA 0xA1EE, Sonork 100.10030
Blackadder: Baldrick, do you know what irony is?
Baldrick: Yeah, it's like goldy and bronzy only it's made of iron.

Re: ADO.NET -vs- ODBC.NET

David Salter4-Feb-03 10:17

David Salter

4-Feb-03 10:17

I don't know about Sybase, but with Oracle I've found that ODBC.NET works better than OleDb. The OleDb class doesn't support all the different field types available whereas ODBC.NET seems to.

Dave

Listing DB2 Servers on the Network

Vasudevan Deepak Kumar3-Feb-03 23:35

Vasudevan Deepak Kumar

3-Feb-03 23:35

Hi,

Is there a way to list all DB2 Servers on the network just like we do with SQLDMO for SQL Servers in C#.

Thanks and Regards,

Deepak Kumar Vasudevan
http://deepak.portland.co.uk/

Default form in Access 2000

56789012343-Feb-03 20:56

5678901234

3-Feb-03 20:56

I have Access 2000 database with number of forms. How can I make one of them default, which is loaded when database is opened?

Re: Default form in Access 2000

David Wulff4-Feb-03 1:11

David Wulff

4-Feb-03 1:11

Do you want to set this via the Microsoft Access application or through ADO/etc? I don't know about the latter approach (I've looked at all the "MSys" tables but can't see anything to suggest it, and the docs are useless as ever), but on the off chance it's the former look under "Tools | Startup..." in the main application menu.

David Wulff
http://www.davidwulff.co.uk

Re: Default form in Access 2000

56789012344-Feb-03 2:05

5678901234

4-Feb-03 2:05

Thank you, this is exactly what I need.

Does anyone have any tutorials on using SQL with C++..

IrishSonic3-Feb-03 11:09

IrishSonic

3-Feb-03 11:09

Hiya does anyone have any tutorials or links on using C++ with SQL. I know C++ already but want to learn SQL. I will be using Visual C++ 6.0.
All I know is there is a header file called sql.h.

Thanks for any help..
grahamoj.

Re: Does anyone have any tutorials on using SQL with C++..

karl_w4-Feb-03 0:08

karl_w

4-Feb-03 0:08

You know, this is quite the hardest way to interact with a database?

For using the API there are many good examples in the MSDN:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/odbc/htm/dasdkodbcoverview.asp[^]

For SQL-Beginners this site could be helpful (I didn't have a deep look into it, just read the titles):

http://www.w3schools.com/sql/default.asp[^]

Hint: Search for SQL + tutorial on google. There are many other sites.

--

karl

Re: Does anyone have any tutorials on using SQL with C++..

David Wulff4-Feb-03 2:21

David Wulff

4-Feb-03 2:21

karl_w wrote:
http://www.w3schools.com

I'll recommend that one too - W3Schools looks like a great site for learning and quick reference alike, and not just for SQL. It is now added to my bookmarks. Smile | :)

I just took each of their quick tests and got...

HTML: 20/20
XHTML 17/20
CSS: 19/20
XML: 19/20
JavaScript: 20/20
ASP: 20/20
SQL: 20/20

...so I guess I'll be spending my afternoon reading through the XHTML and XML sections. (I only got the CSS question wrong because I missread the question. Honest. *cough* )

David Wulff
http://www.davidwulff.co.uk

Problem setting DataViewState of timestamp after update

bah73033-Feb-03 5:46

bah7303

3-Feb-03 5:46

I am trying to get optimistic concurrency to work updating the employees table onf the northwind database to which I have added a datetime column to act as a timestamp. I am having trouble setting the timestamp column in the dataset after updating the dataAdapter. The update command stored procedure works, but because I cannot update the dataViewstate.Original of the timestamp column I cannot perform another update to the same column without refilling the dataset. I know the "timeStamp" parameter is being set by the stored proceudre because I can retrieve the new timestamp value from the parameter in the datasets _RowUpdated event. It seems like the update to the columns should happen automatically base on what info I can find. AmWhat am I missing. Help. I have included the updateCommand and _RowUpdated code below.

Thanks,
Burke

// oleDbUpdateCommand1
//
this.oleDbUpdateCommand1.CommandText = "[up_Employees_Update]";
this.oleDbUpdateCommand1.CommandType = System.Data.CommandType.StoredProcedure;
this.oleDbUpdateCommand1.Connection = this.oleDbConnection1;
this.oleDbUpdateCommand1.Parameters.Add(new System.Data.OleDb.OleDbParameter("RETURN_VALUE", System.Data.OleDb.OleDbType.Integer, 4, System.Data.ParameterDirection.ReturnValue, false, ((System.Byte)(10)), ((System.Byte)(0)), "", System.Data.DataRowVersion.Current, null));
this.oleDbUpdateCommand1.Parameters.Add(new System.Data.OleDb.OleDbParameter("employeeID", System.Data.OleDb.OleDbType.Integer, 4, System.Data.ParameterDirection.Input, false, ((System.Byte)(10)), ((System.Byte)(0)), "EmployeeID", System.Data.DataRowVersion.Current, null));
this.oleDbUpdateCommand1.Parameters.Add(new System.Data.OleDb.OleDbParameter("firstName", System.Data.OleDb.OleDbType.VarWChar, 10, "FirstName"));
this.oleDbUpdateCommand1.Parameters.Add(new System.Data.OleDb.OleDbParameter("lastName", System.Data.OleDb.OleDbType.VarWChar, 20, "LastName"));
this.oleDbUpdateCommand1.Parameters.Add(new System.Data.OleDb.OleDbParameter("title", System.Data.OleDb.OleDbType.VarWChar, 30, "Title"));
this.oleDbUpdateCommand1.Parameters.Add(new System.Data.OleDb.OleDbParameter("timeStamp", System.Data.OleDb.OleDbType.DBTimeStamp, 8, System.Data.ParameterDirection.InputOutput, false, ((System.Byte)(0)), ((System.Byte)(0)), "TimeStamp_ST", System.Data.DataRowVersion.Original, null));

private void oleDbDataAdapter1_RowUpdated(object sender, System.Data.OleDb.OleDbRowUpdatedEventArgs e)
{
int rowsUpdated = (int)oleDbDataAdapter1.UpdateCommand.Parameters["RETURN_VALUE"].Value;
string employeeName = oleDbDataAdapter1.UpdateCommand.Parameters["FirstName"].Value + " " + oleDbDataAdapter1.UpdateCommand.Parameters["LastName"].Value;

if (rowsUpdated != 1)
{
e.Command.Cancel();
addToListBox("Attepmt to update employee:" + employeeName + " returned " + rowsUpdated.ToString());
}
else
{
addToListBox("RowUpdated returned:" + oleDbDataAdapter1.UpdateCommand.Parameters["RETURN_VALUE"].Value.ToString() + " TimeStamp was :" + oleDbDataAdapter1.UpdateCommand.Parameters["TimeStamp"].Value.ToString());
}

DateTime dt = (DateTime)oleDbDataAdapter1.UpdateCommand.Parameters["TimeStamp"].Value;
addToListBox("New timestamp for " + employeeName + " = " + dt.ToString());

e.Row["TimeStamp_ST"] = dt.ToString();
e.Row.AcceptChanges();

// for (int i=0;i<=e.Row.Table.Columns.Count; i++)
// {
// addToListBox(e.Row.Table.Columns[i].ColumnName.ToString());
//
// }
//e.Row["TimeStamp"] = (DateTime)oleDbDataAdapter1.UpdateCommand.Parameters["NewTimeStamp"].Value;

//object str = (object)e.Row["NewTimeStamp",DataRowVersion.Original];
//addToListBox("TimeStamp str=" + str.ToString());
//DataRow cr = e.Row["TimeStamp",DataRowVersion.Original];
//cr["TimeStamp",DataRowVersion.Original] = (DateTime)oleDbDataAdapter1.UpdateCommand.Parameters["NewTimeStamp"].Value;

}

SQL Server transaction Log

Spiros3-Feb-03 5:09

Spiros

3-Feb-03 5:09

Hi everybody
I am using SQL Server 2000. The size of my actual data is 110MB. On the other hand the size of the respective transaction log is 7GB. Is the logical? If not is there a way to reduce it? Note that I use SQL Server's 2000 shrink menu option but the size will not reduce. IMHO this is tooooo much!!!!

Thank you in advance for your help

Spiros Prantalos
Miami the place to be!!

Re: SQL Server transaction Log

Bernhard Hofmann3-Feb-03 5:27

Bernhard Hofmann

3-Feb-03 5:27

Go to the properties of your database, on the "Options" tab, choose "simple" recovery model, and make sure autoshrink is set.

Re: SQL Server transaction Log

Spiros3-Feb-03 5:32

Spiros

3-Feb-03 5:32

Thank you very much!! That was the solution!!

Spiros Prantalos
Miami the place to be!!

C# and Data Blobs

GrahamS3-Feb-03 2:20

GrahamS

3-Feb-03 2:20

The problem I have is as follows:

I have a large number of classes (each having different data members, Confused | :confused:

over 300) which I wish to store the member data within a data blob in a SQL DB (Just one data table). The DB table has the class type and a data blob. Upon retriving the data from the table, the class type is viewed to determine which class to address, and then call the class to extract the data blob. In C++ I would have used a memcpy(), is there a good way of creating and extracting the data blobs, or equiverant to memcpy without having to use unmanaged code.

whats eqivalent for cursor in ADO.NET

pushpi2-Feb-03 17:48

pushpi

2-Feb-03 17:48

Hi
i am newbee in ADO .NET , just curious to know ,whats equivalent to cursor in ADO .NET or how does ADO .NET uses Cursor and LOCKS !!
Dead | X|

P.S. PATWAL

SQL connection problem

pushpi1-Feb-03 0:38

pushpi

1-Feb-03 0:38

i need to insert huge database in sql table
the problem
1) i need to know any method/process by which u may guess the connection has break
2) if connection is brek i need to roll back all the inserts
any idea ?
WTF | :WTF:

P.S. PATWAL

Re: SQL connection problem

karl_w1-Feb-03 10:11

karl_w

1-Feb-03 10:11

First of all, you didn't mention how you contact your database and what db you use (or do you mean MS SQL-Server by "sql table"?)

1) Can't say any particular without knowing how you contact database. But you could check the return value of your data-access-method. There should be an error code for lost connection.
2) If you don't use autocommit, it should be the database's job not to store any data that's not commited.

--

karl

Re: SQL connection problem

pushpi2-Feb-03 17:45

pushpi

2-Feb-03 17:45

hi thanks for paying attention to my query
i got solution for my problem

i just needed to use transation for updates Roll eyes | :rolleyes:

thanks again !

P.S. PATWAL

Problem with C# and MySQL

Snowjim31-Jan-03 5:18

Snowjim

31-Jan-03 5:18

Hello

I have som problem i hope you could help me with

First of al:
My computer name JIMMY-217
I have installd Mysql on my local computer and done no changes to it(it is running)

I have installd the SQL Server Service Manager, and its running(but i dont know where the sql files i located or how to change them).

I have the MyODBC installd(working)

My problem is to get connected with MySQL servern in C#.

I have tryed on the foolowing ways

closed the SQL Server Service Manager and only have the MySql(WinMySQLAdmin) running

this is the connection code:

SqlConnection dataConnection = new SqlConnection();<br />
dataConnection.ConnectionString = "Integrated Security=true;Initial Catalog = mysql; Data Source=localhost"; <br />
		<br />
dataConnection.Open();

But i get the Following error:
Cannot open database requested in login 'mysql'

mysql is a database that is i in the mysql server from start as example or somthing, if this is wrong how do i type to get the correct connection(adress)

I have tryed this turtorial(http://www.devarticles.com/art/1/250) and got it working with the Access file, but not with the SQL server.

If i start up the SQL Server Service Manager and make som changes for example
(Initial Catalog = Northwind), then it will connect to this server but it will say that it cant find the database, but this is not so inportant i think, the main thing is to get the connection to MySQL servern to work.

I hope you got som ides on this problem Big Grin | :-D

I have on more problem, in the mysql(WinMySQLAdmin) -> databases i cant get teh creat and delete commands, i think it has somthing to do with the login, i have to login on root or somthing, but how do i login with a diffrent user? i have tryd to change the my.ini but this didnt help.

Best Regards

Jimmy

Re: Problem with C# and MySQL

Daniel Turini31-Jan-03 5:38

Daniel Turini

31-Jan-03 5:38

The SqlConnection from the System.Data.SqlClient is for connecting to a MS SQL Server. If you are trying connect to your MySql, try a OLEDB provider and use the OleDbConnection class.
Other way is by using the ODBC.NET library from MS.

I see dumb people

Re: Problem with C# and MySQL

Snowjim31-Jan-03 6:36

Snowjim

31-Jan-03 6:36

Thanks for the help

I Think this code is right but i need to connect it to MySql.

OleDbConnection Myconnection = null; <br />
OleDbDataReader dbReader = null; <br />
<br />
Myconnection = new OleDbConnection (@"Provider=Microsoft.Jet.OLEDB.4.0; User Id=; Password=; Data Source=C:\familyTree.mdb"); <br />
Myconnection.Open();

I dont know how to change this code so it will work with mysql(have look along time)

I know that i have to change the User Id and pass to one that can loggon to the SQL server, but what do i change the Data Source to? (my computer name is JIMMY-217, but i dont know how to get the right adress to connect)
Then the first((@"Provider=Microsoft.Jet.OLEDB.4.0;) i probely have to change to.

Hope you have an ide on this

Best regards

Jimmy

Re: Problem with C# and MySQL

kaschimer31-Jan-03 6:54

kaschimer

31-Jan-03 6:54

In addition to what has already been posted, you might want to try the tool at this link:

http://www.devhood.com/tools/tool_details.aspx?tool_id=655[^]

It seems to be a fully-managed provider for MySQL. I haven't tried it myself, but I did download the personal version (free). If you want to deploy it in a product or "real" application, it costs a little, but you get more features such as transactions, connection pooling, etc.

As was mentioned before, the SqlClient classes are designed specifically for MS SQL Server.

RabidK

Last Visit: 31-Dec-99 18:00 Last Update: 26-Jun-24 20:04

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