by Dinesh Thakur Category: Servlet with MySql Database

This is known To Logical operator, which checks the condition, and then execute.

I made a table named 'org' into a database named 'dbase' within the reference of mySql(php myAdmin). Now, i import all the java packages required by user. After calling all the packages i make a class named 'MySqlOROperater' extends the 'HttpServlet'. Now to use serviceMethod() which will getting the request from doGet() for output. After then load all the required Drivers. Some mandatory variable also to define like resultset this variable will responsible for getting the value from desired Columns and rows. Connection variable, which will establish the link between the database and actual code (frontEnd and backEnd).  And the PreparedStatement this variable does execute the given query like executeQuery() as (SELECT emp_id, last_name,salary,job_id FROM org WHERE salary >=10000 OR job_id LIKE '%man%').and in the end the doGet() method has to be used while getting the Output on the web Browser.

For getting value in a manner way, i use 'HTML' code tags which will present the Output on the Web Browser in a tabular form.

import java.io.IOException;

import java.io.PrintWriter;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MySqlOROperater extends HttpServlet
   {
       public void service(HttpServletRequest rq, HttpServletResponse rp)throws IOException, ServletException
         {
              rp.setContentType("text/html");
              PrintWriter disp = rp.getWriter();
              String driver = "com.mysql.jdbc.Driver";
              String url = "jdbc:mysql://localhost/dbase";
              String uid = "root";
              String psw = "root";
              Connection con=null;
              PreparedStatement ps = null;
              ResultSet rs;
              try
               {
                    Class.forName(driver);
                    con = DriverManager.getConnection(url,uid,psw);
                    ps=con.prepareStatement("SELECT emp_id, last_name,salary,job_id FROM org WHERE salary >=10000 OR job_id LIKE '%man%'");
                    rs = ps.executeQuery();
                                String title = "Employee's Info With Using of OR Query";
                    String docType ="<!doctype html public \"-//w3c//dtd html 4.0 " + "transitional//en\">\n";
                                disp.println(docType + "<html>\n" + "<head><title>" + title + "</title></head>\n" +
                    "<body bgcolor=\"#f4efef\">\n" + "<h3 align=\"center\">" + title + "</h3>\n" + "<ul>\n" +
                                "<table width=\"50%\" border=\"1\" align=\"center\">\n" + "<th>Employee Id</th><th>Last Name</th><th>Salary</th><th>Job Id</th>\n"+ "</body> </html>");
                    while(rs.next())
                         {
                                int e_id = rs.getInt("emp_id");
                                    String l_name = rs.getString("last_name");
                                    int sal = rs.getInt("salary");
                                    String j_id=rs.getString("job_id");
                                    disp.println("<tr><td align=\"center\">" + e_id +  "<td align=\"center\">" + l_name +"<td align=\"center\">" + sal +"<td align=\"center\">" + j_id +"</td></tr>" );        
                         }     
               }          
                                            catch(Exception e) 
                                          {
                                               e.printStackTrace();
                                          }
                                               disp.close();
          }
                                       public void doPost(HttpServletRequest rq,HttpServletResponse rp)throws IOException,ServletException
                                                 {
                                                 doGet(rq,rp);
                                                 }
   }
WEB.XML
 
<servlet>
   <servlet-name>MySqlOROperater</servlet-name>
   <servlet-class>MySqlOROperater</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlOROperater</servlet-name>
   <url-pattern>/MySqlOROperater</url-pattern>
</servlet-mapping>




About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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