In this section we will discuss how addtime() function is used with select statement using java servlet.
Mysql SELECT ADDTIME() Function using Java Servlet
In this section we will discuss how addtime() function is used with select statement using java servlet.
ADDTIME function adds a time value with datetime into the pre existing datetime. Syntax of ADDTIME() function ADDTIME (expr1, expr2) where expr1 is a 'datetime' value and expr2 is a 'time' value. Now, since I have to use this function in java servlet program, therefore I have created a java servlet class named MysqlAddTimeServlet which extends the HttpServlet class. In the body of class I overridden the method doGet() and created an objects of HttpServletRequest and HttpServletResponse into its parameter. Inside the doGet() method first I set the mime type that in which format the browser will show the output. In the next line I used the getWriter() method of ServletResponse interface with the object of HttpServletResponse. HttpServletResponse interface extends this method from the ServletResponse. In continue we have to make a connection between java code and database system. So, since I am using Mysql in the example given below therefore, I am loading the driver of mysql and make a connection by using the getConnection() method of DriverManager class. It returns a Connection. Further I am passing the query "SELECT ADDTIME( '2010-07-27 4:41:34:2.30','1:30:34:2.30') AS time_after_adding" (This query will return a time after adding 1hr 30 mins and 2.30 seconds into the dateTime 2010-07-27 06:12:08 ) into the parameter of prepareStatement() method of Connection interface which gives an object of PreparedStatement interface. In the next line I used the executeQuery() method of PreparedStatement interface which returns a ResultSet object that holds the result of query. At last I have extracted the result from the ResultSet object.
Example :
MysqlAddTimeServlet.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 MysqlAddTimeServlet extends HttpServlet
{
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws IOException, ServletException
{
res.setContentType("text/html");
PrintWriter pw = res.getWriter();
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://192.168.10.13/data";
String uid = "root";
String psw = "root";
String sql = "SELECT ADDTIME('2010-07-27 4:41:34:2.30','1:30:34:2.30') AS time_after_adding";
Connection con;
PreparedStatement ps;
ResultSet rs;
try
{
Class.forName(driver);
con = DriverManager.getConnection(url,uid,psw);
ps = con.prepareStatement(sql);
rs= ps.executeQuery();
pw.println("<html><table><tr>");
pw.println("<td><b>time_after_adding</b></td>");
pw.println("<tr>");
while(rs.next())
{
String time = rs.getString(1);
pw.println("<tr><td>"+time+"</td></tr>");
}
}
catch(SQLException sx)
{
pw.println("sx");
}
catch(ClassNotFoundException cx)
{
pw.println(cx);
}
}
}
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>mysqlDate</display-name> <servlet> <servlet-name>MysqlAddTimeServlet</servlet-name> <servlet-class>MysqlAddTimeServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>MysqlAddTimeServlet</servlet-name> <url-pattern>/MysqlAddTimeServlet</url-pattern> </servlet-mapping> </web-app>
Output :
When you will execute the above example you will get the output as :
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