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what is the right way to fetch only one record from the table where many records of same types exist there ?
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Because you asked in this forum, rather than the Database forum, I assume you mean a DataTable, not a database table, where an SQL solution would be appropriate, so I will recommend you look at Linq and select and take in particular.
If you are looking for SQL please post in the Database forum. I'll still help you there, although I should be asleep already.
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The generic answer is to use a cursor.
Specifically it really depends on the database engine - for instance in Oracle PL/SQL you can use a loop command to iterate through a table.
Continuous effort - not strength or intelligence - is the key to unlocking our potential.(Winston Churchill)
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There are many other ways besides using a cursor, which have inherent problems depending on the situation.
I know the language. I've read a book. - _Madmatt
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GuyThiebaut wrote: The generic answer is to use a cursor.
That doesn't sound like a good idea to me.
All major databases provide alternatives to that. Oracle certainly does.
At this point I am not sure that answer isn't just wrong.
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I think I may be misunderstanding his question - I understood him to be asking how does one iterate through a result that returns multiple rows one row at a time...
Since it does not sound like a good idea, to you, could you provide me with better suggestions please as I always want to learn from my mistakes - thanks.
Continuous effort - not strength or intelligence - is the key to unlocking our potential.(Winston Churchill)
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If you want to return one record then you should construct the query to do just that.
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Sure but given:
"I understood him to be asking how does one iterate through a result that returns multiple rows one row at a time"
How would you do this without a cursor?
Continuous effort - not strength or intelligence - is the key to unlocking our potential.(Winston Churchill)
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This is the C# forum.
So the correct way to do that would be to return the result set (complete or subset) and interate it in C#.
But if one wants to return on record then one structures the query appropriately.
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The easiest way is to use the DISTINCT clause.
EDIT: I do not know who downvoted my answer and why. But let me explain to you why I suggested DISTINCT and not TOP as suggested by other posters. A part of the question is
love yadav wrote: where many records of same types exist
That means the OP wants to return one record from each type (each set of distinct values) and not just the first row. TOP 1 will return just the first row not matter how many distinct values are there in the result set.
modified on Sunday, July 31, 2011 11:42 PM
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If you're using MySQL, you can say Limit 1
The difficult we do right away...
...the impossible takes slightly longer.
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Top (1) could be an option. If you are talking about LINQ, try FirstOrDefault.
"The worst code you'll come across is code you wrote last year.", wizardzz[ ^]
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what i do to retrive the primary key of table which is autoincreamented in the table
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Your going to have to describe a bit more what you're trying to do. Getting the value of the key depends on what you're really trying to retrieve and do with it.
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There are three ways and each has a slightly different meaning:
1. SCOPE_IDENTITY()
2. @@IDENTITY
3. IDENT_CURRENT()
To know more, google these terms.
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Hi,
I am working on a project where I receive an MP3 file used in the broadcast industry. However sometimes the MP3 file has dead air so to speak at the beginning and end of the file. I would like to be able to trim this automatically so that I can calculate the appropriate length of the MP3 file, and not broadcast the dead air.
Any idea how to trim the MP3 on both ends for silence?
Thank you and much appreciated,
Glenn
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google search result for C# MP3 Trim[^]2nd result on first page...
Continuous effort - not strength or intelligence - is the key to unlocking our potential.(Winston Churchill)
modified on Saturday, July 30, 2011 1:42 PM
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Along with Guy's response, this[^] article may help in determining the points where the silence ends and begins.
/ravi
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Hi,
I'm a bit puzzled here and feel silly asking this question. I know how to open a new URL, read the response back from the web, etc if I initiate the request. Where I'm stuck is how do I do this if I don't initiate the request.
Here is what I'm trying to do. A distribution center is going to call my Web Server via a Web Service. I'm supposed to obtain the fields of information they are passing to me via a Web GET request. How is this done?
Thank you,
Glenn
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There is a WebRequest object that allows you to make http requests, see this for a specific answer to your question: http://support.microsoft.com/kb/307023[^]
Normally, when consuming web-services, the client uses a set proxy class generated from a web service description. This creates intermediary classes for sending the data up and down the wire and proxy classes to handle the consumption of the remote methods. If you are consuming a third party service, it is worth asking the provider how to generate these first as hand-rolling can be a PITA. If you are writing the services yourself, you'll be able to just add the service as a reference. Right click the client project and select "Add service reference" and point it at your definition. Both ASMX (IIRC) and WCF services provide service definitions out the box.
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hello everyone
i need a suggestion, actually my C# project developed on vista
32-bit i3 system generate error on vista 64-bit AMD processor system.
error is .........
<pre lang="css">
Problem signature:
Problem Event Name: CLR20r3
Problem Signature 01: myapp.exe
Problem Signature 02: 3.0.1.5
Problem Signature 03: 4e33b2b6
Problem Signature 04: mscorlib
Problem Signature 05: 2.0.0.0
Problem Signature 06: 47577b16
Problem Signature 07: f8f
Problem Signature 08: 80
Problem Signature 09: System.IO.FileNotFoundException
OS Version: 6.0.6001.2.1.0.256.6
Locale ID: 1033
</pre>
this one is error and as i searched about it i found one of dll may be not
found related with excel file creation module.
but i added microsoft excel 12.0 object library and my project
run on win7 64-bit amd processor system.
so give me any suggestion if u know about this error
thank u in advance
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We have no idea what you're app does, what is uses, other than Office, or what file it's looking for. Most of the error details you posted are utterly useless. The only useful bit what the FileNotFound exception.
Does the machine have the appropriate version of Office installed?? If not, you need to install it. The office Interop library is not enough.
If your code is using OleDb to read the data in an Excel file, you'll have to specify that. The connection string you used would also need to be shown.
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thank u so much for ur reply 
after ur reply
i tried to run my project without using excel module
and related dll and still i got this error........
mainly i used dll
- imapi2.interop
- Interop.IWshRuntimeLibrary : to create shortcut file
- Interop.shell32
- Interop.WbemScripting
that's all...........
now i m more confused. project executed on win7 with 64 bit AMD Processor
but failed on Vista with 64bit AMD processor... 
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