Re: Question regarding old post (ResultSet and DataTable)
create table mybean (id int primary key, name varchar, age int) bla bla
bla
//make a model
class MyBean implements Serializable {
private String name;
private int age;
}
//create your idataprovider
private class ResultSetDataProvider implements IDataProvider
{
private Connection c;
public ResultSetDataProvider (Connection _c){
c = _c;
}
public Iterator iterator(int start, int count) {
String query = SELECT name, age FROM mybean LIMIT + start + , + count;
PrepareStatement pq = c.createStatement(query );
ResultSet set = pq.executeQuery();
//make a list to carry your records via the bean to your datatable
ListMyBean dataList = new LinkedListMyBean();
while(set.next()){
//create your bean for each record, hopefully JDBC 4 should soon be here
MyBean bean = new MyBean();
bean.setName(set.getString(name));
bean.setAge(set.getInt(age));
dataList.add(bean);
}
return dataList.iterator();
}
public int size() {
String countQ = SELECT COUNT(ID) FROM TABLE;
PrepareStatement pq = c.createStatement(countQ);
ResultSet set = pq.executeQuery();
if(set.next())
return set.getInt(1);
else
return 0;
}
public IModel model(Object arg0) {
return new Model((MyBean)arg);
}
}
//i would not know if there is some other more efficient manner but this is
as simple enough
// and it works with DataView, Paging, DataTable
this should not be too hard, is it? or you need something else
On 8/23/07, dtoffe [EMAIL PROTECTED] wrote:
Uhh, well... yes, you are right.
Excuse me but I fail to see how that could help to solve the problem I
presented, please keep in mind that I'm not native english speaker and
perhaps I'm not using the proper words, I'll try to explain that more
precisely.
As I said in my previous post, I do my database queries in this way:
ResultSet rs = cs.executeQuery();
In fact, later I'll use a code generator to ease the task, but let's
assume for simplicity that I get the result in a java.sql.ResultSet. But,
as
stated in the Wicket Extension Javadoc, I must create the DataTable
instances in this way:
DataTable table = new DataTable(datatable, columns, new
UserProvider(), 10);
Specifically, the third parameter must implement
wicket.markup.repeater.data.IDataProvider; which ResultSet doesn't
implement, so I must provide for a means to overcome this.
I didn't intended to mean that ResultSets are more generic that
DataProviders. When I talked about a general way of handling ResultSet I
tried to mean independently of whether I'm querying a Database Table,
Stored
Porcedure, with read-only or read-write cursors, uni or bi-directional,
and
so. I'm concerned about how well this will go in regard of sortable and
pageable tables.
Perhaps there is a mean to do all that already in the Wicket library,
but I havent found it yet. In the examples I've seen so far the database
is represented by some kind of static list, like in the ContactsDatabase
and
ContactGenerator classes in the DataTable example, but I'm looking for a
way
of using data from queries to a database engine.
The way I see it, I'll have to develop a class which could perhaps
extends ResultSet, or one of the RowSet implementations, and implements
the
IDataProvider interface, am I right on this one ??
Thanks for your help !!
Daniel
igor.vaynberg wrote:
actually idataprovider is more generic then resultset :)
-igor
On 8/22/07, dtoffe [EMAIL PROTECTED] wrote:
Hi !!
I've found this old thread:
http://www.nabble.com/RE%3A-DataView-%28extensions%29-tf1287013.html#a3423281
If there are new or better ways to do this that came up after this
thread, I'm also interested in knowing. Having a way of easily handling
the database resultset and a list of the resultset headers (column
titles) would be great, the more generic, the better.
Thanks !!
Daniel
--
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Re: Question regarding old post (ResultSet and DataTable)
perhaps you can email frank and ask him, it is unfortunate he did not post his code on a wiki page somewhere. http://www.nabble.com/displaying-java.sql.Timestamp-tf1333211.html#a3561689 -igor On 8/22/07, dtoffe [EMAIL PROTECTED] wrote: Uhh, well... yes, you are right. Excuse me but I fail to see how that could help to solve the problem I presented, please keep in mind that I'm not native english speaker and perhaps I'm not using the proper words, I'll try to explain that more precisely. As I said in my previous post, I do my database queries in this way: ResultSet rs = cs.executeQuery(); In fact, later I'll use a code generator to ease the task, but let's assume for simplicity that I get the result in a java.sql.ResultSet. But, as stated in the Wicket Extension Javadoc, I must create the DataTable instances in this way: DataTable table = new DataTable(datatable, columns, new UserProvider(), 10); Specifically, the third parameter must implement wicket.markup.repeater.data.IDataProvider; which ResultSet doesn't implement, so I must provide for a means to overcome this. I didn't intended to mean that ResultSets are more generic that DataProviders. When I talked about a general way of handling ResultSet I tried to mean independently of whether I'm querying a Database Table, Stored Porcedure, with read-only or read-write cursors, uni or bi-directional, and so. I'm concerned about how well this will go in regard of sortable and pageable tables. Perhaps there is a mean to do all that already in the Wicket library, but I havent found it yet. In the examples I've seen so far the database is represented by some kind of static list, like in the ContactsDatabase and ContactGenerator classes in the DataTable example, but I'm looking for a way of using data from queries to a database engine. The way I see it, I'll have to develop a class which could perhaps extends ResultSet, or one of the RowSet implementations, and implements the IDataProvider interface, am I right on this one ?? Thanks for your help !! Daniel igor.vaynberg wrote: actually idataprovider is more generic then resultset :) -igor On 8/22/07, dtoffe [EMAIL PROTECTED] wrote: Hi !! I've found this old thread: http://www.nabble.com/RE%3A-DataView-%28extensions%29-tf1287013.html#a3423281 If there are new or better ways to do this that came up after this thread, I'm also interested in knowing. Having a way of easily handling the database resultset and a list of the resultset headers (column titles) would be great, the more generic, the better. Thanks !! Daniel -- View this message in context: http://www.nabble.com/Question-regarding-old-post-%28ResultSet-and-DataTable%29-tf4314874.html#a12287761 Sent from the Wicket - User mailing list archive at Nabble.com. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Question regarding old post (ResultSet and DataTable)
Hi !!!
Thanks for your reply, this solution is simple, easy to understand and
is not hard to code at all. My only objection would be the MyBean class, if
I understood it right, the DataProvider is tied to the bean in a way that
makes it not reusable:
String query = SELECT name, age FROM mybean LIMIT + start + , +
count;
bean.setName(set.getString(name));
bean.setAge(set.getInt(age));
What I mean is, what happens if I want to query another table, do I have
to change the ResultSetDataProvider implementation, or provide another
implementation for each table ??
I'm not sure if is it even possible to do what I want, surely it would
be more complex and hard to do, but if it saves from creating custom code
for each query, I guess it would justify the extra work.
In most web usages, this implementation is ok because you don't have
that much database queries, but at my work we have been asked to port a
desktop application to a web implementation, and it uses lots of queries
with flexible filtering criteria, for example (Visual Basic pseudocode):
recordset1 = ExecuteQuery(SELECT a, b, c FROM table1);
datagrid1.setColumns(a, b, c);
datagrid1.setRecordSet(recordset1);
datagrid1.refresh();
Perhaps this simplified Visual Basic example shows what I'm trying to
do, as you can see, I don't have to cast the recordset to any specific bean
type, it's just a bunch of cells. That's why I'm looking for that kind of
more abstract approach.
Thanks for your help !!!
Daniel
Ayodeji Aladejebi wrote:
create table mybean (id int primary key, name varchar, age int) bla bla
bla
//make a model
class MyBean implements Serializable {
private String name;
private int age;
}
//create your idataprovider
-
//i would not know if there is some other more efficient manner but this
is
as simple enough
// and it works with DataView, Paging, DataTable
this should not be too hard, is it? or you need something else
On 8/23/07, dtoffe [EMAIL PROTECTED] wrote:
Uhh, well... yes, you are right.
Excuse me but I fail to see how that could help to solve the problem
I
presented, please keep in mind that I'm not native english speaker and
perhaps I'm not using the proper words, I'll try to explain that more
precisely.
-
--
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http://www.nabble.com/Question-regarding-old-post-%28ResultSet-and-DataTable%29-tf4314874.html#a12295661
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Re: Question regarding old post (ResultSet and DataTable)
Done, I've offered to write some example of use for the wiki or example page. Thanks !! Daniel igor.vaynberg wrote: perhaps you can email frank and ask him, it is unfortunate he did not post his code on a wiki page somewhere. http://www.nabble.com/displaying-java.sql.Timestamp-tf1333211.html#a3561689 -igor -- View this message in context: http://www.nabble.com/Question-regarding-old-post-%28ResultSet-and-DataTable%29-tf4314874.html#a12297009 Sent from the Wicket - User mailing list archive at Nabble.com. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Question regarding old post (ResultSet and DataTable)
Hi Ayodeji ! I fully agree with you specially if you have few tables and adhere totally to ORM. But consider what happens when yo have to fill a DataTable with the result of three+ tables joined, with subselects, group by and dinamic where clauses... Would you consider correct to define one Bean-based DataProvider for each one of such resultsets ?? They are not domain entities, they are just rows !! I always had some problems with this side of ORM, sometimes you don't retrieve a list of entities, sometimes the result is more like a spreadsheet, and you don't have an easy way of dealing with that based on beans. What happens if you call a Stored Procedure and you just don't know how many columns are returned ?? This is the problem I would like to solve. Of course I want to do it the Wicket way, to be able to enjoy all the benefits already provided by the framework. I don't want to avoid IDataProvider, I just want to be less tied to the idea of retrieving beans from the database. This issue troubled me since the very first time I heard about ORM. Of course all your concepts regarding the size of the resultset etc. are completely valid and they must be dealt with. I'm sorry I haven't had time yet to explore the code you sent me, I'll see it over the weekend and post it again next week. Thanks for your help !! Daniel Ayodeji Aladejebi wrote: i think its proper to have a Dataprovider for each table. why i enjoy dataprovider in wicket is that it gives me this feeling that SELECT * FROM TABLE will not return 1 million records and crash my application, its gives you a simple way to fetch the data you want to display per time and you can create a many dataprovider as possible or even implement some internal session state logic to tell IDataprovider which table to fetch. its up to your implementation. you will also loose the flexibility you have with yur models if you avoid IDataProvider however actually i think i makes sense for someone to donate a robust JDBCDataProvider to wicket stuff because attempting to do this for criteria matter, you can only hope you are not dealing with complex data types -- View this message in context: http://www.nabble.com/Question-regarding-old-post-%28ResultSet-and-DataTable%29-tf4314874.html#a12306193 Sent from the Wicket - User mailing list archive at Nabble.com. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Question regarding old post (ResultSet and DataTable)
Hi !!
I've found this old thread:
http://www.nabble.com/RE%3A-DataView-%28extensions%29-tf1287013.html#a3423281
I hope this link works OK, just in case I quote here the relevant part:
I have come up with my own subclass of DataTable and implementation of
IDataProvider to display any arbitrary database java.sql.ResultSet.
-
The code is actually quite compact; when I'm finished I'll post it to the
list if there is any interest.
I'm trying to fill a DataTable with the ResultSet obtained from
executing a query:
cs = con.prepareCall({ call Region_SelectAll });
rs = cs.executeQuery();
After I while I discovered that there is no easy or evident way of
filling the DataTable from a ResultSet, I have to provide custom
DataProviders which implement IDataProvider. In case there is some work done
on a generic approach, even if incomplete or undocumented, I'm interested in
taking a look at it.
If there are new or better ways to do this that came up after this
thread, I'm also interested in knowing. Having a way of easily handling the
database resultset and a list of the resultset headers (column titles) would
be great, the more generic, the better.
Thanks !!
Daniel
--
View this message in context:
http://www.nabble.com/Question-regarding-old-post-%28ResultSet-and-DataTable%29-tf4314874.html#a12285785
Sent from the Wicket - User mailing list archive at Nabble.com.
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To unsubscribe, e-mail: [EMAIL PROTECTED]
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Re: Question regarding old post (ResultSet and DataTable)
actually idataprovider is more generic then resultset :)
-igor
On 8/22/07, dtoffe [EMAIL PROTECTED] wrote:
Hi !!
I've found this old thread:
http://www.nabble.com/RE%3A-DataView-%28extensions%29-tf1287013.html#a3423281
I hope this link works OK, just in case I quote here the relevant
part:
I have come up with my own subclass of DataTable and implementation of
IDataProvider to display any arbitrary database java.sql.ResultSet.
-
The code is actually quite compact; when I'm finished I'll post it to
the
list if there is any interest.
I'm trying to fill a DataTable with the ResultSet obtained from
executing a query:
cs = con.prepareCall({ call Region_SelectAll });
rs = cs.executeQuery();
After I while I discovered that there is no easy or evident way of
filling the DataTable from a ResultSet, I have to provide custom
DataProviders which implement IDataProvider. In case there is some work
done
on a generic approach, even if incomplete or undocumented, I'm interested
in
taking a look at it.
If there are new or better ways to do this that came up after this
thread, I'm also interested in knowing. Having a way of easily handling
the
database resultset and a list of the resultset headers (column titles)
would
be great, the more generic, the better.
Thanks !!
Daniel
--
View this message in context:
http://www.nabble.com/Question-regarding-old-post-%28ResultSet-and-DataTable%29-tf4314874.html#a12285785
Sent from the Wicket - User mailing list archive at Nabble.com.
-
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: Question regarding old post (ResultSet and DataTable)
Uhh, well... yes, you are right. Excuse me but I fail to see how that could help to solve the problem I presented, please keep in mind that I'm not native english speaker and perhaps I'm not using the proper words, I'll try to explain that more precisely. As I said in my previous post, I do my database queries in this way: ResultSet rs = cs.executeQuery(); In fact, later I'll use a code generator to ease the task, but let's assume for simplicity that I get the result in a java.sql.ResultSet. But, as stated in the Wicket Extension Javadoc, I must create the DataTable instances in this way: DataTable table = new DataTable(datatable, columns, new UserProvider(), 10); Specifically, the third parameter must implement wicket.markup.repeater.data.IDataProvider; which ResultSet doesn't implement, so I must provide for a means to overcome this. I didn't intended to mean that ResultSets are more generic that DataProviders. When I talked about a general way of handling ResultSet I tried to mean independently of whether I'm querying a Database Table, Stored Porcedure, with read-only or read-write cursors, uni or bi-directional, and so. I'm concerned about how well this will go in regard of sortable and pageable tables. Perhaps there is a mean to do all that already in the Wicket library, but I havent found it yet. In the examples I've seen so far the database is represented by some kind of static list, like in the ContactsDatabase and ContactGenerator classes in the DataTable example, but I'm looking for a way of using data from queries to a database engine. The way I see it, I'll have to develop a class which could perhaps extends ResultSet, or one of the RowSet implementations, and implements the IDataProvider interface, am I right on this one ?? Thanks for your help !! Daniel igor.vaynberg wrote: actually idataprovider is more generic then resultset :) -igor On 8/22/07, dtoffe [EMAIL PROTECTED] wrote: Hi !! I've found this old thread: http://www.nabble.com/RE%3A-DataView-%28extensions%29-tf1287013.html#a3423281 If there are new or better ways to do this that came up after this thread, I'm also interested in knowing. Having a way of easily handling the database resultset and a list of the resultset headers (column titles) would be great, the more generic, the better. Thanks !! Daniel -- View this message in context: http://www.nabble.com/Question-regarding-old-post-%28ResultSet-and-DataTable%29-tf4314874.html#a12287761 Sent from the Wicket - User mailing list archive at Nabble.com. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
