Want to fetch first two row from database

i'm having a database with multiple rows. I want to fetch first two rows form it dynamically, what should i have to do???.plz help....

the data comes from external source and updating the database, at the same time i've to read only first two rows, plz explain.

Similar Messages

How to fetch first 4 records from database.

hi experts.i am inexperience in this field.
please tell me suppose i want to extract only 4 records from the database ,
what is the select statement for this .
best regards.
subhasis.

Hi
use this program as example.
u wil get solution.
REPORT ZSEN_ABAP_TABLE                         .
Tables : mara.
data : wa_mara type mara,
       it_mara type table of mara.
SELECT * UP TO 4 ROWS FROM MARA INTO TABLE it_mara.
loop at it_mara into wa_mara.
Write : / wa_mara-MATNR,
         wa_mara-MTART,
         wa_mara-BISMT.
endloop.
Thanks
Senthil

Does using "fetch first N rows only" make /*+ FIRST_ROWS([N]) */ hint redundant?

I know the FIRST_ROWS hint tells the optimizer to minimize time to first row. I know the new 12c functionality for "FETCH [FIRST|NEXT] [N] ROWS [ONLY|WITH TIES]"fetch first/next N rows only/with ties" will implement the query using ROW_NUMBER(). Should I leave hint in case it improves performance, or does the FETCH FIRST clause make this hint redundant?

maybe the answer to this question is more complicated then I assumed at first: as Randolf Geist wrote in his presentation Everything You Wanted To Know About FIRST_ROWS_n But Were Afraid To Ask a rownum predicate implicitly defines a first rows n optimization. So I guessed that the fetch first clause would trigger a similar optimization. But a rownum predicate and a fetch first clause are not transformed into the same operation:
create table t
as
select rownum id
from dual
connect by level <= 1000000;
select id
from t
where rownum <= 5;
   ID
    1
    2
    3
    4
    5
| Id | Operation          | Name | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT   |      |     5 |    25 |     2   (0)| 00:00:01 |
|* 1 | COUNT STOPKEY     |      |       |       |            |          |
|   2 |   TABLE ACCESS FULL| T    |     5 |    25 |     2   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   1 - filter(ROWNUM<=5)
select id
from t
fetch first 5 rows only;
   ID
    1
    2
    3
    4
    5
| Id | Operation              | Name | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT       |      | 1000K|    24M|   427   (1)| 00:00:01 |
|* 1 | VIEW                  |      | 1000K|    24M|   427   (1)| 00:00:01 |
|* 2 |   WINDOW NOSORT STOPKEY|      | 1000K| 4882K|   427   (1)| 00:00:01 |
|   3 |    TABLE ACCESS FULL   | T    | 1000K| 4882K|   427   (1)| 00:00:01 |
Predicate Information (identified by operation id):
   1 - filter("from$_subquery$_002"."rowlimit_$$_rownumber"<=5)
   2 - filter(ROW_NUMBER() OVER ( ORDER BY NULL )<=5)
Looking at a CBO trace for the two operations I see signs of a first rows optimization only for the query with the rownum predicate:
Final query after transformations:******* UNPARSED QUERY IS *******
SELECT "T"."ID" "ID" FROM "C##TEST"."T" "T" WHERE ROWNUM<=5
First K Rows: Setup begin
And so I think there is no first rows optimization for the fetch first clause. Of course the analytics would make an optimization for fast response almost impossible if there is an order in the query since in this case the analytics have to read the complete set before the filtering takes place.
Regards
Martin Preiss

How to select rows from database like 10 to 20 etc

Hi Experts,
I want to select rows from database like row number 10 to row number 20.How could it be done?

HI,
   First get the data into the INTERNAL TABLE from the FLAT FILE and read the internal table using the index.
    ex: 1) Read table ITAB index 10.
          2) Read table ITAB index 20.
or use as said by Srinivas Gurram, to get the range of records using where condition to the loop.
<REMOVED BY MODERATOR>
Edited by: Ravi Kumar on Jun 9, 2008 4:01 PM
Edited by: Alvaro Tejada Galindo on Jun 9, 2008 3:16 PM

HOW TO DELETE THE ROW FROM DATABASE

hI,
Iam pasting my code below.My problem isi retrieve rows from database and display them in jsp page in rows.For each row there is delete hyperlink.Now when i click that link i should only delete the row corresponding to that delete link temporarily but it should not delete the row from database now.It should only delete the row from database when i click the save button.How can i do this can any one give some code.
thanks
naveen
[email protected]
<%@ page language="java" import="Utils.*,java.sql.*,SQLCon.ConnectionPool,java.util.Vector,java.util.StringTokenizer" %>
<html>
<head>
<meta http-equiv="Content-Language" content="en-us">
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<title>Item Details</title>
<script>
function submitPage()
document.details.action = "itemdetails.jsp" ;
document.details.submit();
</script>
</head>
<body>
<form name="details" action="itemdetails.jsp" method="post">
<%
ConnectionPool pool;
Connection con = null;
Statement st;
ResultSet rs =null;
%>
<table border="0" cellpadding="0" cellspacing="0" width="328">
<tr>
<td width="323" colspan="4"><b>Reference No :</b> <input type="text" name="txt_refno" size="14">
<input type="submit" value="search" name="search" ></td>
</tr>
<tr>
<td width="81" bgcolor="#000099"><font color="#FFFFFF"><b>Item Code</b></font></td>
<td width="81" bgcolor="#000099"><font color="#FFFFFF"><b>Item No</b></font></td>
<td width="81" bgcolor="#000099"><font color="#FFFFFF"><b>Amount </b></font></td>
<td width="80" bgcolor="#000099"> </td>
</tr>
<%
pool= new ConnectionPool();
Utils utils = new Utils();
double total =0.00;
String search =utils.returnString(request.getParameter("search"));
if(search.equals("search"))
try
String ref_no =utils.returnString(request.getParameter("txt_refno"));
String strSQL="select * from ref_table where refno='" + ref_no + "' ";
con = pool.getConnection();
st=con.createStatement();
rs = st.executeQuery(strSQL);
while(rs.next())
String itemcode=rs.getString(2);
int item_no=rs.getInt(3);
double amount= rs.getDouble(4);
total= total + amount;
%>
<tr>
<td width="81"><input type=hidden name=hitem value=<%=itemcode%>><%=itemcode%></td>
<td width="81"><input type=hidden name=hitemno value=<%=item_no%>><%=item_no%></td>
<td width="81"><input type=hidden name=hamount value=<%=amount%>><%=amount%></td>
<td width="80"><a href="delete</td>
</tr>
<%
}catch(Exception e){}
finally {
if (con != null) pool.returnConnection(con);
%>
<tr>
<td width="323" colspan="4">
<p align="right"><b>Total:</b><input type="text" name="txt_total" size="10" value="<%=total%>"></td>
</tr>
<tr>
<td width="323" colspan="4">
<input type="button" value="save" name="save"></td>
</tr>
</table>
</form>
</body>
</html>

You mean when you click on the hyperlink you want that row to disappear from the page, but not delete the row from the database until a commit/submit button is pressed?
Personally, I think I'd prefer that you have a delete checkbox next to every row and NOT remove them from the display if I was a user. You give your users a chance to change their mind about their choice, and when they're done they can see exactly which rows will be deleted before they commit.
You know your problem, of course, so you might have a good reason for designing it this way. But I'd prefer not removing them from the display. JMO - MOD

Problem in deleting row from database in table component

Hi,
I have a table component that its content change by diffrent links.
in this table i have a hyperlink in each row to deleting that row from dataBase.
so i must get the current row .
i do it like this:
define a rowset in the page that have a delete query :
delete from response where responseID=?
in action of delete hyperlink ,i have:
Integer responseId=(Integer)responseDataProvider.
getValue("#{currentRow.value['responseID']}") ;
getSessionBean1().getResponseRowSet().setObject(1,responseId);
getSessionBean1().getResponseRowSet().execute();
but in first line occure a exception:
illigalArgument #{currentRow.value['responseID']}
thanks.

by using data table
first you should get current record (row that recived action)
then delete it by using data provider.
I do not think that you could execute delete statement using rowSets because they just can provide Select statements.
btw , following code will retrive clicked row from data table and
delete that row
try {
RowKey rk = getTableRowGroup1().getRowKey();
if (rk != null) {
testDataProvider.removeRow(rk);
testDataProvider.commitChanges();
} catch (Exception ex) {
log("ErrorDescription", ex);
error(ex.getMessage());
hth
masoud

Use Preparedstatement to delete several rows from database

Hello everyone,
I am trying to delete multiple rows from database at one time using Preparedstatement.
It works well when I tried in SQL directly,the sql query is as follows:
delete from planners_offices where planner ='somename' and office in ( 'officeone', 'officetwo', 'officethree')
I want to delete those 3 rows at one time.
But when I am using preparedstatement to implement this function, it does not work. It did not throw any exception, but just does not work for me, the updated rows value always returns "0".
Here is my simplified code:
PreparedStatement ps = null;
sqlStr = " delete from PLANNERS_OFFICES where planner = ? and office in (?) "
Connection con = this.getConnection(dbname);
try
//set the sql statement into the preparedstatement
ps = con.prepareStatement(sqlStr);
ps.setString(1,"somename");
ps.setString(2,"'officeone','officetwo','officethree'");
int rowsUpdated =ps.executeUpdate();
System.out.println(rowsUpdated);
//catch exception
catch (SQLException e)
System.out.println("SQL Error: " + sqlStr);
e.printStackTrace();
catch (Exception e) {
e.printStackTrace();
} finally {
this.releaseConnection(dbname, con);
try{
ps.close();
}catch (SQLException e){
e.printStackTrace();
rowsUpdated always give me "0".
I tried only delete one record at one time, "ps.setString(2, "officeone");", it works fine.
I am guessing the second value I want to bind to the preparedstatement is not right, I tried several formats of that string, it does not work either.
Can anyone give me a clue?
Thanks in advance !
Rachel

the setString function in a preparedStatement doesn't just do a replace with the question mark. It is doing some internal mumbojumbo(technical term) to assign your variable to the ?.
If you are looking to do your statement, then you will need to put in the correct of # of question marks as you need for the in clause.
delete from PLANNERS_OFFICES WHERE PLANNER = ? and office in (?,?,?)
If you need to allow for one or more parameters in your in clause, then you will need to build your SQL dynamically before creating your prepared statement.
ArrayList listOfOfficesToDelete ;
StringBuffer buffer = new StringBuffer("DELETE FROM PLANNERS_OFFICES WHERE PLANNER = ? AND OFFICE IN (");
for(int i = 0; i < listOfOfficesToDelete.size(); i++ )
   if( i != 0 )
       buffer.append(",");
   buffer.append("?");
buffer.append(")");
cursor = conn.prepareStatement( buffer.toString() );
cursor.setString(1, plannerObj);
for(int i = 0; i < listOfOfficesToDelete().size(); i++ )
    cursor.setString(i+1, listOfOfficesToDelete.get(i) );
cursor.executeUpdate() ;

When using private browsing to view image results in Safari 5.1.3, only the first two rows of results are visible, the following four or so rows display greyed out place holders, and the safe search button is inoperable. Suggestions?

When using private browsing to view image results in Safari 5.1.3, only the first two rows of results are visible, the following four or so rows display greyed out place holders, the remainder of the results page is blank, and the safe search button is inoperable. When I turn off private browsing and refresh the page, everything works again.
Anyone else having this problem?

I have got the same behaviour after the last Safari Update to 5.1.3. It seems that Safari now handles some scripts in a new way. If you debug the Google Website, you will see, that there is some Javascript Error, that seems to prevent to write into local cache. After some searching I wasn't able to finde a solution for this problem, other then disabling Javascript while private browsing to prevent the script loading. You then are able to use Google with the old layout. The option to disable JavaScript can be found in the Menu "Developer", wich has to be enabled in Safari in the options first.
In my opinion this is a bug that is now occuring, because Apple changed something in private browsing and that has to be fixed by Google now, to run again. Or we will have to wait for 5.1.4, as you can read online Apple will change and bugfix the javascript engine in that version, perhaps this fixes the problem as well. I hope so!
If anyone is in the developer program perhaps you could test this with the beta of 5.1.4 and tell us if it works.

I want to delete the transactional record from database table

Hai,
I want to delete the transactional data from database table with out using the dialog programming is it there any trancation for this.
for master data we have the transaction code for delete the records. The t.code is 'OBR2'.
Plz help in that cse.
Thanks and regards,
P.Naganjana Reddy

Hai,
Plz help me urgent.
I am asking i want to delete transactional data from database table without using the dialog programming.
Thanks and Regards,
P.Naganjana

Regarding ssis - Filter first 5 rows from flat file

Hi,
i have a requirement like this every day we receive 10-15 Flat files , we need to load these data into SQL Table ,here nothing is complex for this we need to use foreachloop Container,Dataflowtask..etc. here the issue is each flat file have top 5 rows has
Client information like ( We need to delete First 5 rows) and then insert into SQL Table . please suggest me how to develope the package..

You need to use a script task to read file one by one and remove the first 5 rows from the file. The file name/path can be stored as a variable and read it from the script code. Insert the script task inside the foreach loop container just before importing
the file.
Refer the link to remove a line in .net
http://stackoverflow.com/questions/7008542/removing-the-first-line-of-a-text-file-in-c-sharp
Regards, RSingh

How to compare two rows from two table with different data

how to compare two rows from two table with different data
e.g.
Table 1
ID   DESC
1     aaa
2     bbb
3     ccc
Table 2
ID   DESC
1     aaa
2     xxx
3     ccc
Result
2

Create
table tab1(ID
int ,DE char(10))
Create
table tab2(ID
int ,DE char(10))
Insert
into tab1 Values
(1,'aaa')
Insert
into tab1 Values
(2,'bbb')
Insert
into tab1 Values(3,'ccc')
Insert
into tab1 Values(4,'dfe')
Insert
into tab2 Values
(1,'aaa')
Insert
into tab2 Values
(2,'xx')
Insert
into tab2 Values(3,'ccc')
Insert
into tab2 Values(6,'wdr')
SELECT
tab1.ID,tab2.ID
As T2 from tab1
FULL
join tab2 on tab1.ID
= tab2.ID
WHERE
BINARY_CHECKSUM(tab1.ID,tab1.DE)
<> BINARY_CHECKSUM(tab2.ID,tab2.DE)
OR tab1.ID
IS NULL
OR
tab2.ID IS
NULL
ID column considered as a primary Key
Apart from different record,Above query populate missing record in both tables.
Result Set
ID ID
2 2
4 NULL
NULL 6
ganeshk

How can i fetch the city name from database according the state name

If you have any example of Dyamic List box.
How can i fetch the city name from database according the state name when i select the state name in a dynamic list box.
Thanks

When i run the this code it is giving the an exception
org.apache.jasper.JasperException: javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.faces.el.EvaluationException: javax.faces.FacesException: javax.faces.FacesException: Can't instantiate class: 'com.mypackage.MyBean'.. class com.mypackage.MyBean : java.lang.NullPointerException
     org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:541)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:417)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:346)
     com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:152)
     org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
     org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:233)
     com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:107)
     com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
     com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:137)
     javax.faces.webapp.FacesServlet.service(FacesServlet.java:214)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:127)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:277)
root cause
javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.faces.el.EvaluationException: javax.faces.FacesException: javax.faces.FacesException: Can't instantiate class: 'com.mypackage.MyBean'.. class com.mypackage.MyBean : java.lang.NullPointerException
     org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:846)
     org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:779)
     org.apache.jsp.test_jsp._jspService(test_jsp.java:95)
     org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:346)
     com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:152)
     org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
     org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:233)
     com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:107)
     com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
     com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:137)
     javax.faces.webapp.FacesServlet.service(FacesServlet.java:214)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:127)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:277)
root cause
javax.faces.el.EvaluationException: javax.faces.FacesException: javax.faces.FacesException: Can't instantiate class: 'com.mypackage.MyBean'.. class com.mypackage.MyBean : java.lang.NullPointerException
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:190)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:143)
     com.sun.faces.application.ApplicationImpl.createComponent(ApplicationImpl.java:406)
     javax.faces.webapp.UIComponentTag.createComponent(UIComponentTag.java:1019)
     javax.faces.webapp.UIComponentTag.createChild(UIComponentTag.java:1046)
     javax.faces.webapp.UIComponentTag.findComponent(UIComponentTag.java:761)
     javax.faces.webapp.UIComponentTag.doStartTag(UIComponentTag.java:451)
     com.sun.faces.taglib.html_basic.SelectOneMenuTag.doStartTag(SelectOneMenuTag.java:487)
     org.apache.jsp.test_jsp._jspx_meth_h_005fselectOneMenu_005f0(test_jsp.java:259)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGroup_005f0(test_jsp.java:219)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGrid_005f0(test_jsp.java:189)
     org.apache.jsp.test_jsp._jspx_meth_h_005fform_005f0(test_jsp.java:160)
     org.apache.jsp.test_jsp._jspx_meth_f_005fview_005f0(test_jsp.java:127)
     org.apache.jsp.test_jsp._jspService(test_jsp.java:86)
     org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:346)
     com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:152)
     org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
     org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:233)
     com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:107)
     com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
     com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:137)
     javax.faces.webapp.FacesServlet.service(FacesServlet.java:214)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:127)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:277)
root cause
javax.faces.FacesException: javax.faces.FacesException: Can't instantiate class: 'com.mypackage.MyBean'.. class com.mypackage.MyBean : java.lang.NullPointerException
     com.sun.faces.application.ApplicationAssociate.createAndMaybeStoreManagedBeans(ApplicationAssociate.java:292)
     com.sun.faces.el.VariableResolverImpl.resolveVariable(VariableResolverImpl.java:97)
     com.sun.faces.el.impl.NamedValue.evaluate(NamedValue.java:145)
     com.sun.faces.el.impl.ComplexValue.evaluate(ComplexValue.java:166)
     com.sun.faces.el.impl.ExpressionEvaluatorImpl.evaluate(ExpressionEvaluatorImpl.java:263)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:160)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:143)
     com.sun.faces.application.ApplicationImpl.createComponent(ApplicationImpl.java:406)
     javax.faces.webapp.UIComponentTag.createComponent(UIComponentTag.java:1019)
     javax.faces.webapp.UIComponentTag.createChild(UIComponentTag.java:1046)
     javax.faces.webapp.UIComponentTag.findComponent(UIComponentTag.java:761)
     javax.faces.webapp.UIComponentTag.doStartTag(UIComponentTag.java:451)
     com.sun.faces.taglib.html_basic.SelectOneMenuTag.doStartTag(SelectOneMenuTag.java:487)
     org.apache.jsp.test_jsp._jspx_meth_h_005fselectOneMenu_005f0(test_jsp.java:259)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGroup_005f0(test_jsp.java:219)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGrid_005f0(test_jsp.java:189)
     org.apache.jsp.test_jsp._jspx_meth_h_005fform_005f0(test_jsp.java:160)
     org.apache.jsp.test_jsp._jspx_meth_f_005fview_005f0(test_jsp.java:127)
     org.apache.jsp.test_jsp._jspService(test_jsp.java:86)
     org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:346)
     com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:152)
     org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
     org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:233)
     com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:107)
     com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
     com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:137)
     javax.faces.webapp.FacesServlet.service(FacesServlet.java:214)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:127)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:277)
root cause
javax.faces.FacesException: Can't instantiate class: 'com.mypackage.MyBean'.. class com.mypackage.MyBean : java.lang.NullPointerException
     com.sun.faces.config.ManagedBeanFactory.newInstance(ManagedBeanFactory.java:229)
     com.sun.faces.application.ApplicationAssociate.createAndMaybeStoreManagedBeans(ApplicationAssociate.java:282)
     com.sun.faces.el.VariableResolverImpl.resolveVariable(VariableResolverImpl.java:97)
     com.sun.faces.el.impl.NamedValue.evaluate(NamedValue.java:145)
     com.sun.faces.el.impl.ComplexValue.evaluate(ComplexValue.java:166)
     com.sun.faces.el.impl.ExpressionEvaluatorImpl.evaluate(ExpressionEvaluatorImpl.java:263)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:160)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:143)
     com.sun.faces.application.ApplicationImpl.createComponent(ApplicationImpl.java:406)
     javax.faces.webapp.UIComponentTag.createComponent(UIComponentTag.java:1019)
     javax.faces.webapp.UIComponentTag.createChild(UIComponentTag.java:1046)
     javax.faces.webapp.UIComponentTag.findComponent(UIComponentTag.java:761)
     javax.faces.webapp.UIComponentTag.doStartTag(UIComponentTag.java:451)
     com.sun.faces.taglib.html_basic.SelectOneMenuTag.doStartTag(SelectOneMenuTag.java:487)
     org.apache.jsp.test_jsp._jspx_meth_h_005fselectOneMenu_005f0(test_jsp.java:259)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGroup_005f0(test_jsp.java:219)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGrid_005f0(test_jsp.java:189)
     org.apache.jsp.test_jsp._jspx_meth_h_005fform_005f0(test_jsp.java:160)
     org.apache.jsp.test_jsp._jspx_meth_f_005fview_005f0(test_jsp.java:127)
     org.apache.jsp.test_jsp._jspService(test_jsp.java:86)
     org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:346)
     com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:152)
     org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
     org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:233)
     com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:107)
     com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
     com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:137)
     javax.faces.webapp.FacesServlet.service(FacesServlet.java:214)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:127)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:277)
root cause
java.lang.ClassNotFoundException: class com.mypackage.MyBean : java.lang.NullPointerException
     java.beans.Beans.instantiate(Unknown Source)
     java.beans.Beans.instantiate(Unknown Source)
     com.sun.faces.config.ManagedBeanFactory.newInstance(ManagedBeanFactory.java:223)
     com.sun.faces.application.ApplicationAssociate.createAndMaybeStoreManagedBeans(ApplicationAssociate.java:282)
     com.sun.faces.el.VariableResolverImpl.resolveVariable(VariableResolverImpl.java:97)
     com.sun.faces.el.impl.NamedValue.evaluate(NamedValue.java:145)
     com.sun.faces.el.impl.ComplexValue.evaluate(ComplexValue.java:166)
     com.sun.faces.el.impl.ExpressionEvaluatorImpl.evaluate(ExpressionEvaluatorImpl.java:263)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:160)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:143)
     com.sun.faces.application.ApplicationImpl.createComponent(ApplicationImpl.java:406)
     javax.faces.webapp.UIComponentTag.createComponent(UIComponentTag.java:1019)
     javax.faces.webapp.UIComponentTag.createChild(UIComponentTag.java:1046)
     javax.faces.webapp.UIComponentTag.findComponent(UIComponentTag.java:761)
     javax.faces.webapp.UIComponentTag.doStartTag(UIComponentTag.java:451)
     com.sun.faces.taglib.html_basic.SelectOneMenuTag.doStartTag(SelectOneMenuTag.java:487)
     org.apache.jsp.test_jsp._jspx_meth_h_005fselectOneMenu_005f0(test_jsp.java:259)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGroup_005f0(test_jsp.java:219)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGrid_005f0(test_jsp.java:189)
     org.apache.jsp.test_jsp._jspx_meth_h_005fform_005f0(test_jsp.java:160)
     org.apache.jsp.test_jsp._jspx_meth_f_005fview_005f0(test_jsp.java:127)
     org.apache.jsp.test_jsp._jspService(test_jsp.java:86)
     org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:346)
     com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:152)
     org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
     org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:233)
     com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:107)
     com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
     com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:137)
     javax.faces.webapp.FacesServlet.service(FacesServlet.java:214)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:127)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:277)
root cause
java.lang.NullPointerException
     javax.faces.model.SelectItem.setValue(SelectItem.java:254)
     javax.faces.model.SelectItem.<init>(SelectItem.java:138)
     javax.faces.model.SelectItem.<init>(SelectItem.java:96)
     com.mypackage.MyBean.fillCountryItems(MyBean.java:80)
     com.mypackage.MyBean.<init>(MyBean.java:28)
     sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
     sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
     sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
     java.lang.reflect.Constructor.newInstance(Unknown Source)
     java.lang.Class.newInstance0(Unknown Source)
     java.lang.Class.newInstance(Unknown Source)
     java.beans.Beans.instantiate(Unknown Source)
     java.beans.Beans.instantiate(Unknown Source)
     com.sun.faces.config.ManagedBeanFactory.newInstance(ManagedBeanFactory.java:223)
     com.sun.faces.application.ApplicationAssociate.createAndMaybeStoreManagedBeans(ApplicationAssociate.java:282)
     com.sun.faces.el.VariableResolverImpl.resolveVariable(VariableResolverImpl.java:97)
     com.sun.faces.el.impl.NamedValue.evaluate(NamedValue.java:145)
     com.sun.faces.el.impl.ComplexValue.evaluate(ComplexValue.java:166)
     com.sun.faces.el.impl.ExpressionEvaluatorImpl.evaluate(ExpressionEvaluatorImpl.java:263)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:160)
     com.sun.faces.el.ValueBindingImpl.getValue(ValueBindingImpl.java:143)
     com.sun.faces.application.ApplicationImpl.createComponent(ApplicationImpl.java:406)
     javax.faces.webapp.UIComponentTag.createComponent(UIComponentTag.java:1019)
     javax.faces.webapp.UIComponentTag.createChild(UIComponentTag.java:1046)
     javax.faces.webapp.UIComponentTag.findComponent(UIComponentTag.java:761)
     javax.faces.webapp.UIComponentTag.doStartTag(UIComponentTag.java:451)
     com.sun.faces.taglib.html_basic.SelectOneMenuTag.doStartTag(SelectOneMenuTag.java:487)
     org.apache.jsp.test_jsp._jspx_meth_h_005fselectOneMenu_005f0(test_jsp.java:259)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGroup_005f0(test_jsp.java:219)
     org.apache.jsp.test_jsp._jspx_meth_h_005fpanelGrid_005f0(test_jsp.java:189)
     org.apache.jsp.test_jsp._jspx_meth_h_005fform_005f0(test_jsp.java:160)
     org.apache.jsp.test_jsp._jspx_meth_f_005fview_005f0(test_jsp.java:127)
     org.apache.jsp.test_jsp._jspService(test_jsp.java:86)
     org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
     com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:346)
     com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:152)
     org.ajax4jsf.framework.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)
     org.ajax4jsf.framework.ajax.AjaxViewHandler.renderView(AjaxViewHandler.java:233)
     com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:107)
     com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:245)
     com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:137)
     javax.faces.webapp.FacesServlet.service(FacesServlet.java:214)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:127)
     org.ajax4jsf.framework.ajax.xmlfilter.BaseFilter.doFilter(BaseFilter.java:277)

What is the best approach to fetch more than 10,000 rows from database ?

Hi Experts,
I am new to JDBC. I have a table containing more than 10,000 rows. I don't want to fetch all of them at one shot, because it takes too much time and consumes too much memory. I want to fetch 500 rows first to return to end user. When end user wants more, I fetch subsequent 500 rows until all 10,000 rows are fetched. But how to do this in JDBC? The most difficult thing to me is how to remember the fetched position so that I can fetch each 500 rows subsequently. Could someone help me on that? Sample code is better. Thank you very much.
Regards,
Skeeter

When you instantiate your (prepared) statement, specify a scrollable resultset --
PreparedStatement stat= connection.prepareStatement(query,
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ResultSet rs= stat.executeQuery();The following method reads 'size' rows, starting at position 'pos' --
void read(int pos, int size) {
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}kind regards,
Jos

Fetching required num of rows from database

i have a database and table in it stores around 256 values it has three fields (channel number,Value,Date&Time) i just need the value ie; second column and that to the first 64 values in database pls can i have a valuable solution from anybody it will be a great help and i need it urgently.Thanks in advance......

In order to provide a more direct answer you will need to provide more details. What kind of database? What do you mean by the "first 64 values"? Is this the first 64 ordered a certain way, or the first 64 that happened to have been entered into the database?
In general you can use LabSQL to access databases. You will need to specify a query string to get your values. Something like (for SQL) "SELECT TOP 64 Value FROM MyTable ORDER BY ..."

How To Question: Can I fetch a row from database and show it as link,on click of thi

Hi:
I am trying to get a row set from database, display it as link/ hotspot then upon clicking of this link to delete that particular row from the database.
I would appreciate if someone there could give some pointers.
Thanks in Advance
Ajith
null

In each row of your table, you need to construct a HREF that submits to a servlet (or JSP) with a GET parameter that references the primary key for that row, e.g.
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