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Updating a Table
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Updating a Table
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Updating a Table |
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#1 |
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Hi,
I have three datatables, the last of which represents a many-to-many relationship. Here's how it looks: Table #1 attID (autoincrement) Attribute Name ProdNumber Table #2 valID (autoincrement) Text Number Department Table #3 attID valID Here's the scenario. I have an empty database that I'm using. I'm retrieving data from a web service and placing it in my datatables. I can easily place the desired data into the first two tables, but not the third one. For that matter, I wouldn't know how to save the data for the third table. I'm certain that some ADO.NET guru out there can help me as you've helped many others. Anyone have any ideas? Thanks, Roshawn |
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#2 |
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The design here is flawed. Table3 serves no purpose. If however this was a
DataRelation then it would provide a constraint where entries in the many side may not exist without an entry in the one side. I think this is what you are looking for. Furthermore, the DataRelation does not need to be saved as it acts as your referential intrgrity cop inside the DataSet -- ( OHM ) - One Handed Man AKA Terry Burns - http://TrainingOn.net "Roshawn Dawson" <udrago@bellsouth.net> wrote in message news:unSAZCFXGHA.3660@TK2MSFTNGP04.phx.gbl... > Hi, > > I have three datatables, the last of which represents a many-to-many > relationship. Here's how it looks: > > Table #1 > attID (autoincrement) > Attribute > Name > ProdNumber > > Table #2 > valID (autoincrement) > Text > Number > Department > > Table #3 > attID > valID > > > Here's the scenario. I have an empty database that I'm using. I'm > retrieving data from a web service and placing it in my datatables. I can > easily place the desired data into the first two tables, but not the third > one. For that matter, I wouldn't know how to save the data for the third > table. > > I'm certain that some ADO.NET guru out there can help me as you've helped > many others. Anyone have any ideas? > > Thanks, > Roshawn |
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#3 |
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Are you trying t get the automatically created value for attID and
valID? If so, David Sceppa has some code that works to return the values for autogenerated PKs. Search for his name here. |
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#4 |
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On Sun, 09 Apr 2006 22:41:01 -0500, Roshawn Dawson <udrago@bellsouth.net> wrote:
>Hi, > >I have three datatables, the last of which represents a many-to-many relationship. Here's how it looks: > >Table #1 >attID (autoincrement) >Attribute >Name >ProdNumber > >Table #2 >valID (autoincrement) >Text >Number >Department > >Table #3 >attID >valID > > >Here's the scenario. I have an empty database that I'm using. I'm retrieving data from a web >service and placing it in my datatables. I can easily place the desired data into the first two >tables, but not the third one. For that matter, I wouldn't know how to save the data for the third >table. > >I'm certain that some ADO.NET guru out there can help me as you've helped many others. Anyone have >any ideas? > >Thanks, >Roshawn I believe your third table is a many to many link table. Is that correct? If so you may have to write code to do the inserts. I don't think the wizards are smart enough to do that. I'm on the way to work now, but will work up some code for you this evening, if some one else hasn't already done that. Basically, to will need to do it like this: 1. Insert to Table1 and get the primary key (Row id?) for the row. 2. Insert to Table2 and get the primary key (Row id?) for the row. 3. Insert the two primary keys (Row ids?) into the third table. Good luck with your project, Otis Mukinfus http://www.arltex.com http://www.tomchilders.com |
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#5 |
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Guest
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OHM: great advice
Aziz: appreciate the resource Otis: it appears that you have just what I'm looking for. Table #3 definitely represents a many-to-many relationship. The difficulty is inserting the correct data into the table itself (inserting into the other two tables are simple enough). Sadly, I haven't found any code using ADO.NET to handle this scenario. However, I am attempting to restructure the tables to see if I can omit the need for a many-to-many relationship. Might not prove fruitful, but I'll try anyway. Thanks, Roshawn |
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#6 |
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You know what, I misread your post. I thought you were trying to add a
constraint. If you are using table3 threre should be no problem. provided that the two keys are a composite PK then it should not be any issue at all. -- ( OHM ) - One Handed Man AKA Terry Burns - http://TrainingOn.net "Roshawn Dawson" <udrago@bellsouth.net> wrote in message news:On1U1KMXGHA.3656@TK2MSFTNGP05.phx.gbl... > OHM: great advice > > Aziz: appreciate the resource > > Otis: it appears that you have just what I'm looking for. Table #3 > definitely represents a many-to-many relationship. The difficulty is > inserting the correct data into the table itself (inserting into the other > two tables are simple enough). > > Sadly, I haven't found any code using ADO.NET to handle this scenario. > However, I am attempting to restructure the tables to see if I can omit > the need for a many-to-many relationship. Might not prove fruitful, but > I'll try anyway. > > Thanks, > Roshawn |
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