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UDT, what's the point?I tried making a simple UDT comprising of a few integers that are closely related, and the user designed type seemed perfect (using visual studio 2005). Easily made and easily installed, and from T-SQL it works as expected. However .. I fail to be able to use this UDT from within the environment? In order to use the data, I usually create a dataset and work with that, but the dataset designed doesn't support UDT. If the designed - which creates the datarow classes and so on - isn't able to handle UDT's, how would you go about using this from within for example C#? foreach (CustomerRow row in ds.Customers) { // How would I use an UDT field here? } Micke Andersson, Sweden. Micke 2.0 wrote:
Show quote > Sorry about the crosspost; not sure in which it belongs. In order to use the UDT on the client, it has to be available locally. > > I tried making a simple UDT comprising of a few integers that are closely > related, and the user designed type seemed perfect (using visual studio > 2005). Easily made and easily installed, and from T-SQL it works as > expected. > > However .. I fail to be able to use this UDT from within the environment? In > order to use the data, I usually create a dataset and work with that, but > the dataset designed doesn't support UDT. If the designed - which creates > the datarow classes and so on - isn't able to handle UDT's, how would you go > about using this from within for example C#? > > foreach (CustomerRow row in ds.Customers) { > // How would I use an UDT field here? > } > > > Micke Andersson, Sweden. So, I have a UDT called Point, and I have retrieved a data reader which contains a field of the Point type. To work with the UDT I'd do something like this: while(dr.Read()) { Point p = (Point)dr[1]; //work with the UDT } Hope this helps Niels -- ************************************************** * Niels Berglund * http://staff.develop.com/nielsb * nielsb at develop dot com * "A First Look at SQL Server 2005 for Developers" * http://www.awprofessional.com/title/0321180593 ************************************************** > In order to use the UDT on the client, it has to be available locally. So, Hmm .. ok. So in a complex databound scenario, say a rather large vs2005 GUI > I have a UDT called Point, and I have retrieved a data reader which > contains a field of the Point type. To work with the UDT I'd do something > like this: > > while(dr.Read()) { > Point p = (Point)dr[1]; > //work with the UDT > } project, there *is* no point, then .. you can't databind against it, since the designer doesn't understand it, and thus you cannot generate typed datasets for it, which means .. that there's no point, really. :( Even if I could generate and use a UDT in a table, I could never use that table from a databound GUI - anywhere. Maybe the next generation of visual studio completes the idea - creating a field of type Point shouldn't really be all that hard, but then again, the dataset designer doesn't even understand Nullable afaik, even though that would seem an obvious thing to implement. Thanks for the help anyway - back to the drawing board for me. /Micke I may be completely off here, but I think you could find the XML data type
useful here (with an appropriate XML Schema), rather than re-inventing the wheel with the UDT. ML --- http://milambda.blogspot.com/
Show quote
"Mikael Andersson" <iptrix@nogmailspam.com> wrote in message Sure you can. Read the data into a List<Point>, or List<MyType> and news:uk5qet7iGHA.4304@TK2MSFTNGP03.phx.gbl... >> In order to use the UDT on the client, it has to be available locally. >> So, I have a UDT called Point, and I have retrieved a data reader which >> contains a field of the Point type. To work with the UDT I'd do something >> like this: >> >> while(dr.Read()) { >> Point p = (Point)dr[1]; >> //work with the UDT >> } > > Hmm .. ok. So in a complex databound scenario, say a rather large vs2005 > GUI project, there *is* no point, then .. you can't databind against it, databind it. But no, DataSets don't understand UDT's. >since the designer doesn't understand it, and thus you cannot generate I agree, both UDT's and Nullable types are poorly supported in DataSets. >typed datasets for it, which means .. that there's no point, really. :( >Even if I could generate and use a UDT in a table, I could never use that >table from a databound GUI - anywhere. > > Maybe the next generation of visual studio completes the idea - creating a > field of type Point shouldn't really be all that hard, but then again, the > dataset designer doesn't even understand Nullable afaik, even though that > would seem an obvious thing to implement. > But you no longer have to rely on DataSets for databinding the UI. Object collections work quite well now. David but its trivial to inherit from the wizard generated typed dataset and add
support. you could also just edit the generated class file. -- bruce (sqlwork.com) Show quote "Mikael Andersson" <iptrix@nogmailspam.com> wrote in message news:uk5qet7iGHA.4304@TK2MSFTNGP03.phx.gbl... >> In order to use the UDT on the client, it has to be available locally. >> So, I have a UDT called Point, and I have retrieved a data reader which >> contains a field of the Point type. To work with the UDT I'd do something >> like this: >> >> while(dr.Read()) { >> Point p = (Point)dr[1]; >> //work with the UDT >> } > > Hmm .. ok. So in a complex databound scenario, say a rather large vs2005 > GUI project, there *is* no point, then .. you can't databind against it, > since the designer doesn't understand it, and thus you cannot generate > typed datasets for it, which means .. that there's no point, really. :( > Even if I could generate and use a UDT in a table, I could never use that > table from a databound GUI - anywhere. > > Maybe the next generation of visual studio completes the idea - creating a > field of type Point shouldn't really be all that hard, but then again, the > dataset designer doesn't even understand Nullable afaik, even though that > would seem an obvious thing to implement. > > Thanks for the help anyway - back to the drawing board for me. > /Micke > > To add to Neil's response, the assembly needs to be available to the client
so that the underlying data can be serialized and desterilized. You can find more information in the SQL Server 2005 Books Online (ms-help://MS.SQLCC.v9/MS.SQLSVR.v9.en/denet9/html/4b0d876c-8066-490e-8e18-327c0e942b19.htm). -- Show quoteHope this helps. Dan Guzman SQL Server MVP "Micke 2.0" <micke@NOekcim.SPAMnet> wrote in message news:eXcMPR6iGHA.1208@TK2MSFTNGP02.phx.gbl... > Sorry about the crosspost; not sure in which it belongs. > > I tried making a simple UDT comprising of a few integers that are closely > related, and the user designed type seemed perfect (using visual studio > 2005). Easily made and easily installed, and from T-SQL it works as > expected. > > However .. I fail to be able to use this UDT from within the environment? > In order to use the data, I usually create a dataset and work with that, > but the dataset designed doesn't support UDT. If the designed - which > creates the datarow classes and so on - isn't able to handle UDT's, how > would you go about using this from within for example C#? > > foreach (CustomerRow row in ds.Customers) { > // How would I use an UDT field here? > } > > > Micke Andersson, Sweden. > > "Dan Guzman" <guzmanda@nospam-online.sbcglobal.net> wrote in message Thanks. I'd already included the assembly in the GUI project, of course, but news:uhyTes7iGHA.1940@TK2MSFTNGP02.phx.gbl... > To add to Neil's response, the assembly needs to be available to the > client so that the underlying data can be serialized and desterilized. > You can find more information in the SQL Server 2005 Books Online > (ms-help://MS.SQLCC.v9/MS.SQLSVR.v9.en/denet9/html/4b0d876c-8066-490e-8e18-327c0e942b19.htm). > > -- > Hope this helps. then I found out that the designer choked on UDT's, and that with VS2005 I found no other reasonable way to do databinding than to use datasets, which can't be used with UDT's - definitions or no definitions included. Yes it works with datareaders, but that's of little real use in my projects anyway, so I'll do things The Old Way for now. Thanks for helping :) /Micke The Books Online contains a Dataset/DataAdapter example using UDTs.
However, this isn't a typed dataset which I guess is the VS 2005 designer issue you are referring to. Like the SqlDataReader, an cast to the UDT is required, AFAIK. -- Show quoteHope this helps. Dan Guzman SQL Server MVP "Mikael Andersson" <iptrix@nogmailspam.com> wrote in message news:%23dDuZy7iGHA.5036@TK2MSFTNGP04.phx.gbl... > > "Dan Guzman" <guzmanda@nospam-online.sbcglobal.net> wrote in message > news:uhyTes7iGHA.1940@TK2MSFTNGP02.phx.gbl... >> To add to Neil's response, the assembly needs to be available to the >> client so that the underlying data can be serialized and desterilized. >> You can find more information in the SQL Server 2005 Books Online >> (ms-help://MS.SQLCC.v9/MS.SQLSVR.v9.en/denet9/html/4b0d876c-8066-490e-8e18-327c0e942b19.htm). >> >> -- >> Hope this helps. > > Thanks. I'd already included the assembly in the GUI project, of course, > but then I found out that the designer choked on UDT's, and that with > VS2005 I found no other reasonable way to do databinding than to use > datasets, which can't be used with UDT's - definitions or no definitions > included. > > Yes it works with datareaders, but that's of little real use in my > projects anyway, so I'll do things The Old Way for now. Thanks for helping > :) > > /Micke > >  |
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