This section gives you brief description of JDBC Steps for making connection with the database, executing the query and showing the data to the user. In this application we have connected to the MySQL database and retrieved the employee names from the dat
This section gives you brief description of JDBC Steps for making connection with the database, executing the query and showing the data to the user. In this application we have connected to the MySQL database and retrieved the employee names from the datThis section gives you brief description of JDBC Steps for making connection with the database, executing the query and showing the data to the user. In this application we have connected to the MySQL database and retrieved the employee names from the database. Here are the JDBC Steps to be followed while writing JDBC program:
Before explaining you the JDBC Steps for making connection to the database and retrieving the employee from the tables, we will provide you the structure of the database and sample data.
Here is the sql script to create table and populate the table with data:
-- Table structure for table `employee` CREATE TABLE `employee` ( `employee_name` varchar(50) NOT NULL, PRIMARY KEY (`employee_name`) ); INSERT INTO `employee` (`employee_name`) VALUES ('Deepak Kumar'), ('Harish Joshi'), ('Rinku roy'), ('Vinod Kumar'); |
Data inserting in MySQL database table:
mysql> insert into employee values('Deepak Kumar'); Query OK, 1 row affected (0.24 sec) mysql> insert into employee values('Harish Joshi'); Query OK, 1 row affected (0.05 sec) mysql> insert into employee values('Harish Joshi'); ERROR 1062 (23000): Duplicate entry 'Harish Joshi' for key 1 mysql> insert into employee values('Rinku roy'); Query OK, 1 row affected (0.03 sec) mysql> insert into employee values('Vinod Kumar'); Query OK, 1 row affected (0.04 sec) mysql> select *from employee; +---------------+ | employee_name | +---------------+ | Deepak Kumar | | Harish Joshi | | Rinku roy | | Vinod Kumar | +---------------+ 4 rows in set (0.04 sec) |
Here is the code of java program that retrieves all the employee data from database and displays on the console:
/* Import JDBC core packages. Following statement imports the java.sql package, which contains the JDBC core API. */ import java.sql.*; public class RetriveAllEmployees{ public static void main(String[] args) { System.out.println("Getting All Rows from employee table!"); Connection con = null; String url = "jdbc:mysql://localhost:3306/"; String db = "jdbc"; String driver = "com.mysql.jdbc.Driver"; String user = "root"; String pass = "root"; try{ Class.forName(driver); con = DriverManager.getConnection(url+db, user, pass); Statement st = con.createStatement(); ResultSet res = st.executeQuery("SELECT * FROM employee"); System.out.println("Employee Name: " ); while (res.next()) { String employeeName = res.getString("employee_name"); System.out.println(employeeName ); } con.close(); } catch (ClassNotFoundException e){ System.err.println("Could not load JDBC driver"); System.out.println("Exception: " + e); e.printStackTrace(); } catch(SQLException ex){ System.err.println("SQLException information"); while(ex!=null) { System.err.println ("Error msg: " + ex.getMessage()); System.err.println ("SQLSTATE: " + ex.getSQLState()); System.err.println ("Error code: " + ex.getErrorCode()); ex.printStackTrace(); ex = ex.getNextException(); // For drivers that support chained exceptions } } } }
Explanation of JDBC Steps:
In this section you learnt about the JDBC Steps necessary for performing database operations.
Output of program:
C:\vinod>javac RetriveAllEmployees.java C:\vinod>java RetriveAllEmployees Getting All Rows from employee table! Employee Name: Deepak Kumar Harish Joshi Rinku roy Vinod Kumar |
Download full code along with JDBC driver
Ads