The JDBC Connection
A Connection object represents a connection with a database. An application may have one or more than one connections with a single database or
many connections with the different databases also.
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.
While making a JDBC connection we go through the following steps :
Step 1 : Register the database driver by using :
Class.forName(\" driver classs for that specific database\" );
Class.forName("com.mysql.jdbc.Driver");
Step 2 : Now create a database connection using :
Connection con = DriverManager.getConnection(url,username,password);
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/art1",art1,art1);
Step 3: Now Create a query using :
Statement stmt = Connection.Statement("select EMP_NAME from EMP");
Step 4 : Exceute the query :
ResultSet rs = stmt.exceuteQuery();
while(rs.next()){
System.out.println(rs.getString(EMP_NAME));
}
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