JDBC ConnectionUrl
The JDBC Connection Url is the mean of connecting a front end application made in java platform to backend database. An object of Connection enables your application to connect database. This all requires a SQL queries to execute and return the result over that connection object. Simlararly,In this Tutorial we want to describe you an example that helps you to understand JDBC Connection url. The code describe you the JDBC Connection between url and a database.
Understand with Example
The package java.sql.* is to be imported, that include all the set of defined classes provides you a network interface between url and database. Here we have a class JdbcConnectionUrl. Inside this class, we have a main method( ) contains a declared list of objects and variable. Now you can see the uses of declared variable in the given below code -
Loading Database Driver: loading of a driver class that invokes Class.forName( ) with the Driver class name passed as an argument. Once the driver is loaded ,you can connect the Java front end application to the backend database. In case the exception occurred in loading a database inside the try block. The catch block handle the exception and println print the exception.
Driver Manager.getConnection ( ) :This method return you a connection object that built your path between url and database.
The Println print the connection url from the variable string url and db.
st = con.createconnection( ) :This method return you an sql object. Once connection is established ,your front-end application is able to interact with backend database. A connection object enables you to send and execute SQL Statement to a backend database.
rs = st.executequery(sql) : This method return you result set object that accept sql query as parameter.The value retrieved from it is assigned in result set rs.The retrieved table row contain a element in sequence.
next( ) :The next method is used to retrieve successively element through the rows from a result set.
Finally the JDBC Connection url is built and println print the url and db,first name and last name from the result set obtained from database.
JdbcConnectionUrl .java
import java.sql.*; public class JdbcConnectionUrl { public static void main(String args[]) { Connection con = null; Statement st = null; ResultSet rs = null; String url = "jdbc:mysql://localhost:3306/"; String db = "komal"; String driver = "com.mysql.jdbc.Driver"; String user = "root"; String pass = "root"; try { Class.forName(driver); con = DriverManager.getConnection(url + db, user, pass); System.out.println("Connection url : "+url + db); st = con.createStatement(); String sql = "select * from customer"; rs = st.executeQuery(sql); System.out.println("First Name \tLast Name"); while (rs.next()) { System.out.print(rs.getString("First_Name") + " \t"); System.out.println(rs.getString("Last_Name")); } } catch (Exception e) { System.out.println(e); } } } |
Output
Connection url : jdbc:mysql://localhost:3306/komal First Name Last Name girish tewari mahendra singh komal singh yogesh pandey pinku tripathi deepak tripathi |