Connection Objects in ADO.NET

Connection Object in ADO.NET:

The connection object is the way ADO.NET's built in data providers to a data source. There are two connection objects that ship with the ADO.NET. The First OleDbConnection object is used to Create connection to any valid OLE DB data source and Second SqlConnection Object  is used connect to Microsoft Sql Sever. just as in ADO.NET use the connection strings to connect to various data sources.

Connection String:

A Connection string is a semicolon delimited set of name value pairs that define the various properties of data base connection. Connection String Specify a wide verity of information, Such as the type of OLE DB provider you are using for your connection to the database.

Syntax of OLE DB Connection String:

"Provider=Microsoft.jet.OLEDB.4.0;Data Source=FilePath;Jet OLEDB;Useri=admin;password= ;"

Connection Object Methods:

There are mainly two methods use in connection Object:

  • The Open() Method

  • The Close() Method

OLEDB Connection Syntax:

Dim Conn As OleDbConnection = New OleDbConnection("Provider=Microsoft.jet.OLEDB.4.0;"+                                                                    "data source=C:\path;"+"Userid=;"+   "password= ;")

Conn.Open()
Conn.Close()

Sql Server Connection Syntax:

Dim Conn As SqlConnection = New
SqlConnection("Initial Catalog-NorthWind;"
                  "Server=   (Local);"+"Uid=sa;"+   "password= ;")                                                                                                           

Conn.Open()
Conn.Close()