Database Discussion Boards

Re: Connection Pooling

Mazdak8-Mar-04 7:59

Mazdak

8-Mar-04 7:59

Thanks.

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

unknown extension file

aguest6-Mar-04 10:59

aguest

6-Mar-04 10:59

i is there someone who know a database with the extension ".DTA" ,and which tools
can i open it ????

Re: unknown extension file

josefg6-Mar-04 13:44

josefg

6-Mar-04 13:44

I hope this[^] helps

Josef

.Data Provider for MySQL

josefg6-Mar-04 4:35

josefg

6-Mar-04 4:35

Has anyone ever used the .Data Provider Library[^] by ByteFX[^]? What are your opinions of it?

Thanks,
Josef

Re: .Data Provider for MySQL

Anonymous6-Mar-04 8:51

Anonymous

6-Mar-04 8:51

I tried using it. It only has partial support for VS so don't expect to be able to drag and drop it onto your form, you will be creating the objects by hand in your own code. If you need to support more than 5 connections then I guess that it is a good alternative if the end user does not want to ponyup the money for a decent backend.

The database that I ended up being more interested in was the MaxDB from the MySql folks that supports triggers and stored procedures. I don't beleive that this .Data Provider supports MaxDB as MaxDB is *not* MySql but rather a open source database developed by the SAP people. MaxDB may be distributed free of charge *if* your application is being distrubuted as open source. Otherwise, it has a healty price tag.

Re: .Data Provider for MySQL

josefg6-Mar-04 23:21

josefg

6-Mar-04 23:21

Thanks for the reply mate.

Also has anyone ever used MySQLDriverCS[^]?

Thanks
Josef

Slightly off topic... choosing db server software

Verdant1235-Mar-04 19:18

Verdant123

5-Mar-04 19:18

does anyone have any links or comments on how to choose a database server product?

i have fairly large database in mysql on linux (os could cange) currently, but it is being bogged down, on some pretty serious hardware, and i think doing some optimized stored procedures,perhaps a full text index, etc would help... i have used a lot of the various databases, but haven't done much performance analysis... any thoughts?

it does a lot of transactions, updates, inserts and selects...
but the biggest slowdown is the relatively low percentage of searches.

Re: Slightly off topic... choosing db server software

Andy Harman9-Mar-04 10:23

Andy Harman

9-Mar-04 10:23

Could you give us an example of one slow search, and what indexes you have in place.

Importing Data in Bulk from SQL to Access

Adnan5625-Mar-04 19:07

Adnan562

5-Mar-04 19:07

I imported data in VC 6.0 using DTSPackage from SQL to Access but importing larger data made the proccess slower. Is there anyway that this could be made faster.

I aslo tried Queries, SELECT and INSERT... SELECT was good but INSERT could not paste the data in bulk... can someone help me plzzzzz

Thnx in Advance

AD

Importing Data in Bulk from SQL to Access

Adnan5627-Mar-04 19:34

Adnan562

7-Mar-04 19:34

Y DONT U PEOPLE HELP ME

Cry | :((

PLZZZZZZZZZZZZZZZZZZZZ

HELPPPPPPPPPPPPPPPPPPP

MEEEEEEEEEEEEEEEEEEEEE

AD

using LIMIT within a SELECT statment

Matt Newman5-Mar-04 7:36

Matt Newman

5-Mar-04 7:36

I am trying to limit the number of items returned from a SQL Server (SQL Server 2000). However when I do something like this ASP.NET gets mad at me:

SELECT * FROM SomeWhere WHERE Something = 'SomeCondition' LIMIT 5

Basically I only want the first 5 results returned. This worked in my experience in MySQL. Could anyone show me how to do it in SQL Server 2000?

^Matt Newman

Re: using LIMIT within a SELECT statment

Henrik Stuart5-Mar-04 7:49

Henrik Stuart

5-Mar-04 7:49

SELECT TOP 5 * FROM SomeWhere WHERE Something = 'SomeCondition'

MSSQL doesn't support "LIMIT x, y" but it can be emulated through a somewhat... icky... nested subselection.

--
Henrik Stuart (http://www.unprompted.com/hstuart/)

Re: using LIMIT within a SELECT statment

Matt Newman5-Mar-04 8:02

Matt Newman

5-Mar-04 8:02

Thanks, thats exactly what I needed.

^Matt Newman

Re: using LIMIT within a SELECT statment

Lee Fuller5-Mar-04 9:18

Lee Fuller

5-Mar-04 9:18

Also consider set rowcount n to stop processing of the result set after n rows (and set rowcount 0 to reset). The set rowcount is especially useful in a stored proc where you want to pass n (the # of rows) as a variable from your components/application.

Cheers,

Lee.

Lee H Fuller
lee@fullerdata.com

Finalize and dispose

sunsmile3-Mar-04 16:19

sunsmile

3-Mar-04 16:19

Hi,
can anyone explain the difference between finalize and dispose methods?Like which is used to release resources and when is best used?. Why are these methods declared as protected?

Any furthur reading suggestions,comments are welcome

Re: Finalize and dispose

Mike Dimmick4-Mar-04 5:20

Mike Dimmick

4-Mar-04 5:20

Asking on the .NET Framework or C# forum would be better.

Finalization is built into the CLR. When the garbage collector collects an object, if it has a finalizer, the object is added to the finalization queue (and the memory containing the object is pushed up into the older generation - it isn't actually collected). A separate thread, the finalization thread, is used to actually call the finalizers. Once the finalizer for the object has run, the object's memory can be collected (unless the object has resurrected itself, but we'll forget that for the moment). The Finalize method is a special hint to the CLR - if you override Finalize, the above takes place.

Dispose is a design pattern (also, with the support of the IDisposable interface). By convention, it allows the programmer to release scarce resources once the object is finished with. You should implement this if you hold a resource that is limited (such as a drawing object, or a database connection) or that could cause contention with other parts of the program (such as files). In these cases, you would normally also have a finalizer to act as a backstop in case the user doesn't call Dispose. You can call GC.SuppressFinalize in your Dispose method to tell the CLR that you've done all the necessary cleanup and it no longer needs to call your finalizer.

The IDisposable interface allows programs and environments to detect whether a Dispose method is implemented without using Reflection (which is a lot more costly). C#'s using block automatically calls IDisposable.Dispose on the controlled object at the end of the block.

See MSDN: Implementing a Dispose Method[^].

Stability. What an interesting concept. -- Chris Maunder

Opening a database connection in a client/server application

girl_lash3-Mar-04 14:37

girl_lash

3-Mar-04 14:37

can someone share me a sample code on how to open a connection in case my database is in the server. I am using MS Access 2000 for my database, and ADO, Visual C++ in my application.
your help is greatly needed...
i've seen some codes about it and im wondering if the user id and password parameters of the open function refers to the database password you set after you created your database. and how dsn string looks like..
please help me..
this is a new thing for me...

Re: Opening a database connection in a client/server application

Rob Graham5-Mar-04 8:48

Rob Graham

5-Mar-04 8:48

Try looking here[^]

Power corrupts and PowerPoint corrupts absolutely. - Vint Cerf

Re: Opening a database connection in a client/server application

girl_lash7-Mar-04 14:46

girl_lash

7-Mar-04 14:46

what if the the server requires a username and password? can i use the same username and password i have set in my workgroup information file?
how should the code look like? please help me...

Re: Opening a database connection in a client/server application

Rob Graham7-Mar-04 17:41

Rob Graham

7-Mar-04 17:41

Microsof Access is not a client/server db, but a file database. To open it on a server from a client workstation, the user account running the application must be able to mount the database as a file share. If the drive on theserver where the database is located is not always mapped to the same drive letter on the client, you will need to specify the datasource in the connection string as a UNC path (\\servername\sharename\path\filename.mdb). Password and username in the connection string must be what the access db (system.mdb) expect, not a server username/password.

Access in not a very robust "client/server" db. SQL server or MSDE would be a better soulution if you need true client/server performance.

Power corrupts and PowerPoint corrupts absolutely. - Vint Cerf

Setting password to a converted database

girl_lash3-Mar-04 13:55

girl_lash

3-Mar-04 13:55

I have an Access database named Data and has set a password for it. When I tried to convert it to prior access database version (because I have to, otherwise, it will cause error in my Visual C++ application durion connection opening) the set database password option is disabled. so, my problem is how can i set a database password if my database has been converted...
please help me...

Re: Setting password to a converted database

Rob Graham5-Mar-04 9:18

Rob Graham

5-Mar-04 9:18

I don't understand why you have to convert it. ADO opens all versions (you just cant use Access 200 features on an access 95 or 97 database. If you are creating the database with ADOX, specify the version you want by add the "Jet OLEDB:Engine Type" property to your connection string (or read it if you are opening an older version and need to know the version).
See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnacc2k/html/adoproperties.asp[^]

Power corrupts and PowerPoint corrupts absolutely. - Vint Cerf

Retrieving Dates from Access Database using ODBC

pavneet3-Mar-04 9:16

pavneet

3-Mar-04 9:16

Got problems in ODBC programming in VC++ 6.0..I'm unable to retrieve Date/Time fields correctly..

sr = SQLBindCol(hstmt,6,SQL_TYPE_TIMESTAMP,date,sizeof(date),&ld);<br />
if(sr != SQL_SUCCESS && sr != SQL_SUCCESS_WITH_INFO)<br />
{<br />
    displayError(sr, "Error in binding 6");<br />
}

datebeing CTime date[11];
Using the above code..

Can somebody please give me some suggestions?

Re: Retrieving Dates from Access Database using ODBC

Rob Graham5-Mar-04 9:59

Rob Graham

5-Mar-04 9:59

SQL_TYPE_TIMESTAMP does not map to a datetime field but to a timestamp

I don't think you can bind directly to a Ctime struct. I think odbc wants
an SQL_C_TYPE_TIMESTAMP structure.

See this[^]

Power corrupts and PowerPoint corrupts absolutely. - Vint Cerf

Re: Retrieving Dates from Access Database using ODBC

pavneet5-Mar-04 10:03

pavneet

5-Mar-04 10:03

It doesn't help either SQL_TYPE_DATE/SQL_C_TYPE_TIMESTAMP they all give the wrong data.

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