Database

Re: External Linked Servers

21-Dec-06 23:49

oh there is .NET 2.0 version as well.

Which is a bit nicer than the .NET 1.1 version

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External Linked Servers

Jay Legue21-Dec-06 3:52

Jay Legue

21-Dec-06 3:52

Hi All,

I am doing some research about External Linked Servers and am hoping that someone can point me towards some best practices information and let me know about any gotchas that I should look out for when using this capability in applications.

Thanks in advance,

---Jay

Frank Kerrigan21-Dec-06 23:54

pls can u mail how to use ajax controls in .net

21-Dec-06 23:54

I've quite a lot of experience in this in a few companies and this is how it generally work

Between SQL server no issues

Between other servers (Progress, Oracle, SyBase etc.....) issues are

* Timeouts in SQL command
* Large data migration or copy of large data chunks fails due to ODBC time outs.
* SQL92 is not a standard standard (work different on different boxes)
* You tend to go for extracts to text files for large data volumes and using dts, as it tends to work

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ODBC Descriptors

Jay Legue21-Dec-06 3:45

Jay Legue

21-Dec-06 3:45

Hi All,

I am doing some research on the use of ODBC descriptors and hope that the community might have some opinions:

Is anybody out there using ODBC descriptors in their applications?
What are you using them for and why?
Are their alternatives to using them?

Thanks in advance,

---Jay

Priya Fernandes21-Dec-06 1:28

Priya Fernandes

21-Dec-06 1:28

I want to implement ajax controls in web application using .net i dont have any idea about this control n i am not getting anythg into my head abt ajax controls pls help me in this matter n mail me to priya.idiol@gmail.com
regards priya

priya fernandes

Re: pls can u mail how to use ajax controls in .net

Colin Angus Mackay21-Dec-06 1:55

21-Dec-06 1:55

Wrong forum - Try the ASP.NET forum.

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Delete query

Tauseef A20-Dec-06 23:38

Tauseef A

20-Dec-06 23:38

hi guys

i have two tables named (table1) and (table2),,

there is a field named ID which belongs to both tables ,,

i want to delete matching records from both tables based on this ID field which is a nvarchar type ,, can any body tell me the exzact query

thanks in advance

hello

Colin Angus Mackay20-Dec-06 23:53

20-Dec-06 23:53

ghumman63 wrote:
there is a field named ID which belongs to both tables

Which way does the relationship go? - You have to delete the child first otherwise you get an integrity violation. However, if you have cascading deletes then you can delete the parent and it will cascade delete the child too. (Most people have this off because it can cause devistation if not used properly)

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Tauseef A20-Dec-06 23:55

Tauseef A

20-Dec-06 23:55

what if there is no relationship between both tables ?

hello

Pete O'Hanlon21-Dec-06 0:23

Pete O'Hanlon

21-Dec-06 0:23

If there is no physical relationship (as specified by a Foreign Key), but an implied (logical) one, then it doesn't matter which order you delete the records. What I would do though, is wrap both deletes in a transaction so that you don't get orphaned rows.

the last thing I want to see is some pasty-faced geek with skin so pale that it's almost translucent trying to bump parts with a partner - John Simmons / outlaw programmer

Deja View - the feeling that you've seen this post before.

Frank Kerrigan21-Dec-06 23:57

A new bie question in regards to ADO

21-Dec-06 23:57

Create a trigger that deletes records from the second trigger based on the deleted values from the first

create trigger dbo.DeleteTrigger on dbo.table1<br />
FOR DELETE<br />
AS<br />
   DELETE table2 <br />
   WHERE table2.ID = ( SELECT ID FROM DELETED)<br />
go

Blog Have I http:\\www.frankkerrigan.com

Irfan Faruki20-Dec-06 22:25

Irfan Faruki

20-Dec-06 22:25

Hi I am noob trying to learn ADO using C# 2005. I am trying to create a simple contact manager that can store contact data. I want to include Add, Edit & Delete buttons so that i can add, edit & delete a record from contract manager. Can anyone tell me how should i go about doing this? I can add the automated data navigator for this but i dont want to do that. I want to write my own code for it. Any help will be appriciated

Thanks
Irfan

I am still learning

Colin Angus Mackay20-Dec-06 22:36

20-Dec-06 22:36

Best approach is to write a DAL (Data Abstraction Layer). This essentially means creating a class (or group of classes) to handle your database interaction. Your application can then call the DAL class(es) rather than the database direct. At a conference I was at a couple of weeks ago one of the speakers gave some excellent advice: If you have anything from your System.Data namespace in the presentation layer (your WinForm or WebForm class, or control classes, etc.) then there is something wrong with the design.

In the DAL class(es) you connect to the database, perform your query, close the connection and return the data.

The way I do it is that each public method in the DAL is a proxy for a stored procedure in the database.

Remember that you can send pretty much and SQL into a SqlCommand. So if you can do it in Query Analyser or SQL Server Management Studio, then you can issue it via a SqlCommand (Just Remember that GO splits the batch, and that isn't supported - you must only issue one batch at a time, but you can have as many SQL Commands as you like in a batch)

Does this help?

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Mairaaj Khan21-Dec-06 0:43

Mairaaj Khan

21-Dec-06 0:43

Colin Angus Mackay wrote:
If you have anything from your System.Data namespace in the presentation layer (your WinForm or WebForm class, or control classes, etc.) then there is something wrong with the design.

If we need DataTable or DataRow, then what should we do Confused | :confused:

________________________________
Success is not something to wait for, its something to work for.

Colin Angus Mackay21-Dec-06 1:58

21-Dec-06 1:58

uroojkhan wrote:
If we need DataTable or DataRow, then what should we do

You don't need those things. They should be converted to business object on their way out of the DAL.

If the application is small enough, you can probably get away with it. But for any application that is large enough you should really look in to a proper 3+ tier architecture splitting the presentation, business, and data layers out from each other.

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Pete O'Hanlon21-Dec-06 2:39

Pete O'Hanlon

21-Dec-06 2:39

uroojkhan wrote:
If we need DataTable or DataRow, then what should we do

Find something better.

Seriously, a DataTable/DataRow does not model your business object. It is just a handy wrapper that Microsoft provided. It does not make for a robust design for several reasons:

1. Suppose that you want to expose your object as a web-service. While .NET knows what a DataTable is, you would have to write your own wrapper for any other platform (e.g. Java).
2. What happens if you change a field name in the database? DataSets (and so on) are loosely coupled. You are more likely to forget to fix a DataSet than you are a properly designed business object.
3. They are large and unwieldy. They provide a lot of overhead because they are so generic. A lot of plumbing is needed to make sure that it works with different types of data.
4. It does not abstract the UI from the database. You still need knowledge of the database to use them. Which makes more sense to you? A class with a property called CustomerName or a DataRow with a value dr["cust_name"] (which must also be cast to the appropriate type).

Irfan Faruki21-Dec-06 4:25

Irfan Faruki

21-Dec-06 4:25

Thanks guys... Will give i a try

I am still learning

Frank Kerrigan22-Dec-06 0:00

Doubt Regarding Sqldmo View

22-Dec-06 0:00

Go into Google and look for ADO 2.0 tutorials sucg as W3 School and 15 seconds.

Blog Have I http:\\www.frankkerrigan.com

ruparanju20-Dec-06 22:19

ruparanju

20-Dec-06 22:19

I want to create a new view in my database using SQLDMO com class.I encounter with a problem near my text property of the view .
If any one know about this dll.Please help me

Rupa

Return two values

DanB198320-Dec-06 11:59

DanB1983

20-Dec-06 11:59

Hey first of all not sure if this is the right board so i apoligise now if it is not.

Any ways my question is I am using SQL with C#.NET and have a query:

SELECT groups FROM T_USERS
WHERE username = @USERNAME;

SELECT organisation FROM T_ORGANISATIONS
WHERE username = @USERNAME;

which i execute using cmd.ExecuteReader()

However does not seem to be returned in the form reader(0) reader(1).

How do i go about solving this problem (yes I know it is basic so sorry to bore you with it but i am not sure what to search for)

Any advise would be awesome

Thanks

Dan

Re: Return two values

Colin Angus Mackay20-Dec-06 22:39

DateDiff returns in HH:MM format

20-Dec-06 22:39

One reader can return many result sets.

You use Read() to move to the next row in a result set (the result of a SELECT statement), you use MoveNext() to move to the next result set (i.e. to the result of the next SELECT statement)

Does this help?

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Re: Return two values

DanB198321-Dec-06 0:24

DanB1983

21-Dec-06 0:24

Thats magic thanks remmber seeing that some where and when you said that it all fell into place.

Thanks again.

Dan

VK-Cadec20-Dec-06 8:22

VK-Cadec

20-Dec-06 8:22

Hi - Is there a way we could return the result in above format - know of hours, minutes, seconds.

Thanks for your time.

Vani

Re: DateDiff returns in HH:MM format

Colin Angus Mackay20-Dec-06 22:41