class design w/DAAB RSS

• • Reply
  

  dave_m

  Member

  65 Points

  13 Posts

  class design w/DAAB

  Jul 18, 2003 04:09 PM|LINK

  I, too, have been using this for quite a while now and it does save a lot of code writing. I have developed a usage pattern that seems to work, although I'm not sure if it's such a great pattern in terms of maintenence. I usually design classes representing a persisted object to pretty much replicate the schema of a table, and I give the classes methods such as Load, Save and a static List method. Each method has a corresponding stored procedure. So, within my Load method, for example, I set up an array of Output parameters, call SqlHelper.ExecuteNonQuery(...) and then set my object's properties to the the values of the output params. If I need to make a change to the table schema, I then have to rework the code that builds the parameters, and usually have to change all the indices of the params array to make it match the sproc. I have thought about using the cached parameters functionality, but then - since the parameters are dynamically determined, I lose the ability to assign their values to class members explicitly, don't I? The other option is using DataSets instead of objects with properties that match columns. But that seems like going back to the old RecordSet("columnName") days - I really like having strongly typed properties instead. Comments? Regards, David
• • Reply
  

  krome

  Member

  190 Points

  38 Posts

  Re: class design w/DAAB

  Jul 19, 2003 11:14 PM|LINK

  If you use a typed dataset instead of plain-vanilla dataset, there is strong typing of fields. It will "feel" much like you custom data interface classes since the typed dataset essentially is just a hierarchical series of classes that mimic the underlying database structures. Object instances are defined for rows, with typed properties for the columns. Basically the same thing you are coding by hand now from the sound of it...
  Keith Rome
  
  
  MCSD, MCDBA, MCAD, CIC
  
  
• • Reply
  

  ghan

  Participant

  1440 Points

  288 Posts

  Re: class design w/DAAB

  Aug 07, 2003 04:37 PM|LINK

  This is good idea. I did it in this way sometime, but didn't think in this way. But, do you suggest that with using DataSet associated with DataTable, DataColumn and Rows could replace the custom object created by ourselves in BLL, somehow like using the MS DAL in different applications to replace the own developed DAL that is probably different for each application? Or, how about to address the question: when it is suitable to use strong typed DataSet and when to use custom objects?
  MCAD.NET (C#)
  
  
  MCP on: SQL Server 2k Design&Iimplementation, Web Development (VI 6.0) and VB 5.0