In this tutorial you will learn how mysql's like operator is used with servlet
LIKE Operator In MySql Servlet Example
In this tutorial you will learn how mysql's like operator is used with servlet
LIKE Operator comapres a specific character that a pattern matches into a string or not. To matches the specified pattern it uses the wildcards(%, ^, etc).
Example :
In this example first I created a table named userInfo for fetching the data. To use this mysql operator in servlet I created a class named MysqlLike.java which extends the class HttpServlet to support the http functionality to servlet, into which I defined the doGet() method into which the object's of HttpServeltRequest and HttpServletResponse are created. Since we have to use the mysql query so we are required to connect with a database package (here I am using MySql) that's why in further steps I perform the database connectivity with servlet using the java.sql package. In example to use the above operator I use the query "SELECT name FROM UserInfo WHERE name LIKE 'r%'". This query will return the value all the names from the table whose names are started from the character r doesn't matter what are the following characters.
MysqlLike.java
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.SQLException;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MysqlLike extends HttpServlet
{
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException
{
response.setContentType("text/html");
PrintWriter out= response.getWriter();
String className= "com.mysql.jdbc.Driver";
String url= "jdbc:mysql://192.168.10.13/data";
String user="root";
String password="root";
Connection con;
PreparedStatement ps;
ResultSet rs;
try
{
Class.forName(className);
con= DriverManager.getConnection(url, user, password);
String sql= "SELECT name FROM UserInfo WHERE name LIKE 'r%'";
ps= con.prepareStatement(sql);
rs= ps.executeQuery();
out.println("<html><table border=1>");
out.println("<tr><td align=left><b>name</b></td></tr>");
while(rs.next())
{
String nm= rs.getString("name");
out.println("<tr><td align=middle>"+nm+"</td>");
out.println("</tr>");
}
out.println("</table></html>");
rs.close();
ps.close();
con.close();
}
catch(ClassNotFoundException cx)
{
out.println(cx);
}
catch(SQLException sx)
{
out.println(sx);
}
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <display-name>mysqlComparisonFunctionAndOperator</display-name> <servlet> <servlet-name>MysqlLike</servlet-name> <servlet-class>MysqlLike</servlet-class> </servlet> <servlet-mapping> <servlet-name>MysqlLike</servlet-name> <url-pattern>/MysqlLike</url-pattern> </servlet-mapping> </web-app>
Output :
When you will execute the above example you will get the output as :
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