Ado.Net Tutorial
- 1. Presentation Created By : Prabhu R .Net ADO.Net
- 2. Introduction to Ado.net Ado stand for Active Database Object. Before Ado.net we use Ado to access data from database. Basically Ado has automatic driver detection technique and its has only one drawback that it only provide a connected environment so efficiency of system may decrease. ADO.NET is a new database technology used by .NET platform (introduced in 2002). In fact it is a set of classes used to communicate between an application front end and a database. It supports both connected & disconnection mode of data access.
- 3. Difference between ADO and ADO.NET ADO ADO.NET 1.It is a COM based library. 1.It is a CLR based library. 2.Classic ADO requires active connection with the data store. 2.ADO.NET architecture works while the data store is disconnected. 3.Locking feature is available. 3.Locking feature is not available. 4.Data is stored in binary format. 4.Data is stored in XML. 5.XML integration is not possible. 5.XML integration is possible. 6.It uses the object named Recordset to reference data from the data store. 6.It uses Dataset Object for data access and representation. 7.Using Classic ADO, we can obtain information from one table or set of tables through join. We cannot fetch records from multiple tables independently. 7.Dataset object of ADO.NET includes collection of DataTables wherein each DataTable will contain records fetched from a particular table. Hence multiple table records are maintained independently. 8.Firewall might prevent execution of Classic ADO. 8.ADO.NET has firewall proof and its execution will never be interrupted. 9.Classic ADO architecture includes client side cursor and server side cursor. 9.ADO.NET architecture doesn't include such cursors. 10.We cannot send multiple transactions using a single connection instance. 10.We can send multiple transactions using a single connection instance.
- 4. Namespaces used in ADO. Net System.Data It contains the common classes for connecting, fetching data from database. Classes are like as DataTable, DataSet, DataView etc. System.Data.SqlClient It contains classes for connecting, fetching data from Sql Server database. Classes are like as SqlDataAdapter,SqlDataReader etc. System.Data.OracleClient It contains classes for connecting, fetching data from Oracle database. Classes are like as OracleDataAdapter,OracleDataReader etc. System.Data.OleDb It contains classes for connecting, fetching data from any database(like msaccess, db2, oracle, sqlserver, mysql). Classes are like as OleDbDataAdapter,OleDbDataReader etc. System.Data.Odbc It contains classes for connecting, fetching data from any
- 6. Component of ADO.NET architecture The two key components of ADO.NET are Data Providers DataSet
- 7. DataSet Basically it is a small Data structure that may contain multiple datatables from multiple sources. The information in dataset is created inform of XML and is stored with .xsd extention. It support disconnected mode of data access.It has both scrolling mode means forward and backward scrolling mode (fetching of data). DataSet can have multiple Datatable from multiple sources but DataReader is able toread only single Datatable.
- 8. Creating and using a DataSet The typical steps in creating and using a DataSet are: (i)Create a DataSet object (ii) Connect to a database (iii)Fill the DataSet with one or more tables or views (iv)Disconnect from the database (v)Use the DataSet in the application
- 9. Data Provider Data provider is a set of ADO.Net classes that allow us to access a database. Basically, it is a bridge between our application (We can say front-end) and data source. There are following Data Provider : SqlServer Data Provider:-It is used to access data from SqlServer database (for version 7.0 or later). Oracle Data Provider:-It is used to access data from oracle database (for version 8i or later). OleDb Data Provider:-It is used to access data from any database (msaccess, mysql, db2). Odbc Data Provider :-It is used to access data from any database (msaccess, mysql, db2).
- 10. The four Objects from the .Net Framework provides the functionality of Data Providers in the ADO.NET. They are Connection Object Command Object Data Reader Object Data Adapter Object.
- 11. The SQLCONNECTION OBJECT The Connection :-The Connection object which provides a connection to the database
- 12. Command Object The Command :-The Command object which is used to execute a command It provide three methods which are used to execute commands on the database: ExecuteNonQuery: Executes commands that have no return values such as INSERT, UPDATE or DELETE ExecuteScalar : Returns a single value from a database query ExecuteReader: Returns a result set by way of a DataReader object
- 13. Data Adapter Object. data adapter : The DataAdapter serve as a bridge between a DataSet and data source for retrieving and saving data. The DataAdapter provides this bridge by using Fill to load data from the data source into the DataSet and using Update to send changes made in the DataSet back to the data source. The data adapter objects connect a command objects to a Dataset object. They provide the means for the exchange of data between the data store and the tables in the DataSet. An OleDbDataAdapter object is used with an OLE-DB provider A SqlDataAdapter object uses Tabular Data Services with MS SQL Server.
- 14. Data Reader Object The DataReader:- The DataReader object which provides a forward-only, read only, connected recordset Limitations of the DataReader There is not possible to sort, filter, or manipulate the data while using a DataReader, since it is read-only and forward-only.
- 15. Differences between DataSet and DataReader DataSet DataReader DataSet object can contain multiple rowsets from the same data source as well as from the relationships between them. DataReader provides forward-only and read-only access to data. Dataset is a disconnected architecture. Datareader is connected architecture. Dataset can persist data. Datareader can not persist data. A DataSet is well suited for data that needs to be retrieved from multiple tables. It has live connection while reading data DatsSet is slower than DataReader ,Due to overhead. Speed performance is better in DataReader