Retrieve limited rows from single column from mysql database
Question
I am trying to retrieve only last 3 recently added rows from single column from MySql database. Please help in this--
my jsp code:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ page import="java.sql.* "%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title></title>
</head>
<body>
<% Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/eco", "root", "vicky");
PreparedStatement ps = con.prepareStatement("select * from registration");
ResultSet rs=ps.executeQuery();
rs.afterLast();
while(rs.previous()){ %>
<p> <%= rs.getString(2) %> </p>
<%} %>
</body>
</html>
my database structure:
ID username email password
1 vikas vikas5@gmail.com 44
2 Aravind Aravind@gmail.com 12
3 rakesh rakesh@gmail.com 123
4 chandra chnadra@gmail.com 123
5 shiva chinthala@gmail.com 12345
6 sai sai@gmail.com 4321
7 ravi ravi@gmail.com 987654
The ouput getting for me
ravi
sai
shiva
chandra
rakesh
Aravind
vikas
but i want output as
ravi sai shiva
chandra rakesh Aravind
vikas
2 answers
solution1
0 2018-09-24 17:29:20
You need to use Order By with Limit .
-
Order by ID DESCsorts the data in descending order based onIDcolumn. -
LIMIT 3gets the first 3 rows in the sorted data.
Change the following:
PreparedStatement ps = con.prepareStatement("select * from registration");
to
PreparedStatement ps = con.prepareStatement("select * from registration order by ID desc limit 3");
solution2
0 2018-09-24 18:38:47
If you want to get only the last 3 records, then you need to change your query.
You have to write a nested query like this:
SELECT * FROM (select * from registration ORDER BY ID) registration WHERE rownum <= 3 ORDER BY rownum DESC;
Please refer to the following link for further information:
https://www.techonthenet.com/oracle/questions/bottom_records.php
this is very nice and very helpfull site to learn Database and other technology.
i hope it will help you
and also you can do it this query is also work
SELECT * FROM registration ORDER BY ID DESC LIMIT 3;
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