ADO.NET Disconnected Architecture

Fill in the method to load data from a DataSource into a DataSet. Update is to transfer data from a DataSet to a DataSource. DataAdapter is internally a collection of the following 4 methods:

When we call the Fill() method of Adapter, the following action takes place internally.

Siince a DataSet is updatable, changes can be made to data that is loaded into it, like adding, modifying and deleting records. After making all the changes to the data in a dataset if we want to send those changes back to the DataSource then call the Update() method on the DataAdapter that performed the following:

Accessing Data From DataSet DataReader provides us a pointer vases access to the data, so we can get data only in sequential order, whereas a dataset provides us index-based access to data so we can get the data from any location. Dataset is a collection of tables where each table is represented as a DataTable class and identified by the index position. DataTable DataTable is the collection of tables. The following syntax is used for a DataTable: <DataSet>.Tables[Index]/[Name] For example: Ds.Tables[0] Every DataTable is again a collection of Rows and Columns where each row is represented as a DataRow class and identified by its index position. Each column is represented as a DataColumn class and identified by index position or name. DataRow It is a collection of rows. Syntax: <datatable>.Rows[Index]. For example: Ds.tables[0].rows[0] DataColumns It is a collection of Columns. Syntax: <datatable>.Columns[Index] OR columns[Name] For example: Ds.Tables[0].Column[0] Ds.tables[0].rows[0] The following is the syntax for referring to a cell under a Data Table: <datatable>.Rows[row] [col] For example: Ds.Tables[0].Rows[0][0] Ds.Tables[0].Rows[0][“ENO”]

Ds.tables[0].rows[0] For more articles visit my blog: http://dotnetbyabhipatil.blogspot.in