DataReader Question

[timothy]

Hi,

I am trying to decide to use a datareader to retrieve data from MS SQL
Server or use a dataset. I have seen examples retrieve the data using a
reader then loop through the reader and load it into a dataset. Is it
saving that much more time than filling a dataset?

Thanks

 

[David Browne]

Hi,

I am trying to decide to use a datareader to retrieve data from MS SQL
Server or use a dataset. I have seen examples retrieve the data using a
reader then loop through the reader and load it into a dataset. Is it
saving that much more time than filling a dataset?

No. That's exactly what the DataAdapter does behind the scenes.

David

 

[William Ryan eMVP]

Like David mentions, an DataReader is utilized to fill the table. You'll
notice the frequency of the word Reader is Dbexceptions if you examine the
stack trace...that's b/c they are used everywhere underneath.

You could certianly do this, but you'll be writing a lot of code that's
already been written and tested.

John Papa just laid it all out though in MSDN Magazine...
http://www.msdn.microsoft.com/msdnmag/issues/04/06/DataPoints/default.aspx

--
W.G. Ryan MVP Windows - Embedded

http://forums.devbuzz.com
http://www.knowdotnet.com/dataaccess.html
http://www.msmvps.com/williamryan/

 

[Scott M.]

It's not so much about time as it is about memory. A DataReader does not
create copies of your data (as you would have in a DataSet). This is why
you must loop through the DataReader as it is iterating over each record
from the actual DataSource and is not holding all the records in memory.