Programming with ADO'NET By Sam Nasr April 27, 2004

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Programming with ADO.NETBySam NasrApril
27, 2004
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What is ADO.Net?

• ADO.NET ActiveX Data Objects
• A set of libraries included within the .NET
  Framework
• ADO.NET objects are contained in the System.Data
  namespace.

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ADO.Net Terminology

• Data Store an object containing data.
• Data Provider Classes designed to communicate
  with a data store.

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Advantages of ADO.NET

• Built for CLR environment to maximize
  performance.
• Greater Extensibility results can be retrieved
  in XML.
• Allows the use of the Disconnected Objects
  (DataSet)
• Allows multiple dataset objects for a join query.
• Allows update logic when using a Disconnected
  Object.

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• All ADO.NET objects can be separated into 2
  categories
• 1. Connected Objects that communicate directly
  with the database.
• 2. Disconnected Objects that allow the user to
  work with the data offline.

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Connected Objects

• Connection
• Transaction
• DataAdapter
• Command
• Parameter
• DataReader

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Disconnected Objects

• DataSet
• DataTable
• DataView
• DataRow
• DataColumn
• Constraint
• DataRelation

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Syntax for a single query statement

• SqlCommand cmd new
• Sqlcommand(select from customers, _ conn)
• Adapter.fill(ds) to fill a single dataset
• Adapter.fill(ds, customers) to fill a single
  dataset and name it.

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Syntax for a multiple query statement

• SqlCommand cmd new _
• Sqlcommand(select from customers select
  from orders, conn)
• Adapter.fill(ds)
• Ds.tables0.TableName Customers
• Ds.tables1.TableName Orders

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Using .UDL files

• .UDL Universal Data Link
• UDL files store a connection string for any data
  connectivity task.
• Interface is identical to the Data Adapter.