JDBC drivers:
Types:
1. JDBC-ODBC bridge:
The JDBC type 1 driver, also known as the JDBC-ODBC bridge, is a database driver implementation that employs the ODBC driver to connect to the database. The driver converts JDBC method calls into ODBC function calls.
Advantages:
- Almost any database for which an ODBC driver is installed can be accessed, and data can be retrieved.
Disadvantages:
2. Native-API Driver
The JDBC type 2 driver, also known as the Native-API driver, is a database driver implementation that uses the client-side libraries of the database. The driver converts JDBC method calls into native calls of the database API.For example: Oracle OCI driver is a Type 2 Driver.
Advantages:
As there is no implementation of jdbc-odbc bridge, its considerably faster than a type 1 driver.
Disadvantages:
The vendor client library needs to be installed on the client machine.
3 . Network-Protocol Driver(MiddleWare Driver)
Advantages:
Disadvantages:
4. Database-Protocol Driver(Pure Java Driver)
Schematic of the Native-Protocol driver.The JDBC type 4 driver, also known as the Direct to Database Pure Java Driver, is a database driver implementation that converts JDBC calls directly into a vendor-specific database protocol.
Advantages:
Disadvantages:
- Drivers are database dependent, as different database vendors use widely different (and usually proprietary) network protocols.
JDBC Basics – Java Database Connectivity Steps:
Step 1: Loading a database driver: The first thing you need to do before you can open a database connection is to load the JDBC driver for the database.
Class.forName(”sun.jdbc.odbc.JdbcOdbcDriver”);
Step 2: Opening the Connection
To open a database connection you use the java.sql.DriverManager class.
String url = "jdbc:h2:~/test";
String user = "sa";
String password = "";
Connection connection =
DriverManager.getConnection(url, user, password);
Step 3: Creating a jdbc Statement object: Once a connection is obtained we can interact with the database.
Statement statement = connection.createStatement();
A statement object is used to send and execute SQL statements to a database.
Statement: Execute simple sql queries without parameters.
Statement createStatement()
Creates an SQL Statement object.
Prepared Statement: Execute precompiled sql queries with or without parameters.
PreparedStatement prepareStatement(String sql)
returns a new PreparedStatement object. PreparedStatement objects are precompiled
SQL statements.
Callable Statement: Execute a call to a database stored procedure.
CallableStatement prepareCall(String sql)
returns a new CallableStatement object. CallableStatement objects are SQL stored procedure call statements.
Step 4: Closing the Connection
Once you are done using the database connection you should close it. This is done by calling the Connection.close() method, like this:
connection.close();
Example-
import java.sql.*;
class TestRetrieve
{
public static void main(String[] args)
{
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection c=DriverManager.getConnection("Jdbc:Odbc:mydsn");
Statement s=c.createStatement();
ResultSet result1=s.executeQuery("select * from emp");
while(result1.next())
{
System.out.println(result1.getString(1));
System.out.println(result1.getString(2));
}
}catch(SQLException e)
{
System.out.println(e);
}
catch(Exception i)
{
System.out.println(i);
}
}
}
Hello Dinesh
i m new in java and i m working on project that is voice based email system in java.i used ur codes these are perfectly working.i want some help from u bec i hava a problm that is when an email has an attachment then how can show file on the frame that can be downloaded when we recieve it.if u can help then plz do.
simple and good
Where is model here and where is loose coupling???
I want registration example in which action class,dao class and model
Class must exist separetly.I.e registration action, registration dao , user model class exist. plz send
Thanks alot for contents
Thanks Surjeet for learning with us!!!