Connecting to database is language dependent. if we are using Java
A Connection object represents a connection with a database. When we connect to a database by
using connection method, we create a Connection Object, which represents theconnection to the
database. An application may have one or more than one connections with a single database or
many connections with different databases.
We can use the Connection object for the following things:
1). It creates the Statement, PreparedStatement and CallableStatement objects for executing the
SQL statements.
2). It helps us to Commit or roll back a jdbc transactionn.
3). If you want to know about the database or data source to which you are connected then
the Connection object gathers information about the database or data source by the use of
DatabaseMetaData.
4). It helps us to close the data source. The Connection.isClosed() method returns true only if the
Connection.close() has been called. This method is used to close all the connection.
Firstly we need to to establish the connection with the database. This is done by using the
method DriverManager.getConnection(). This method takes a string containing a URL. The
DriverManager class, attempts to locate a driver that can connect to the database represented by
the string URL. Whenever the getConnection() method is called the DriverManager class checks
the list of all registered Driver classes that can connect to the database specified in the URL.
Syntax:
String url = “jdbc: odbc: makeConnection”;
Connection con = DriverManager.getConnection(url, “userID”, “password”);