ramanujam

• May 27th, 2005

 

A RowSet is a disconnected, serializable version of a JDBC ResultSet.  
The RowSet is different than other JDBC interfaces in that you can write a RowSet to be vendor neutral. A third party could write a RowSet implementation that could be used with any JDBC-compliant database. The standard implementation supplied by Sun uses a ResultSet to read the rows from a database and then stores those rows as Row objects in a Vector inside the RowSet. In fact, a RowSet implementation could be written to get its data from any source. The only requirement is that the RowSet acts as if it was a ResultSet. Of course, there is no reason that a vendor couldn't write a RowSet implementation that is vendor specific.  
 
The standard implementations have been designed to provide a fairly good range of functionality. The implementations provided are:  
CachedRowSetImpl - This is the implementation of the RowSet that is closest to the definition of RowSet functionality that we discussed earlier. There are two ways to load this RowSet. The execute( ) method will load the RowSet using a Connection object. The populate( ) method will load the RowSet from a previously loaded ResultSet.  
WebRowSetImpl - This is very similar to the CachedRowSetImpl (it is a child class) but it also includes methods for converting the rows into an XML document and loading the RowSet with an XML document. The XML document can come from any Stream or Reader/Writer object. This could be especially useful for Web Services.  
JdbcRowSetImpl - This is a different style of implementation that is probably less useful in normal circumstances. The purpose of this RowSet is to make a ResultSet look like a JavaBean. It is not serializable and it must maintain a connection to the database.  
The remaining two implementations are used with the first three implementations:  
FilteredRowSetImpl - This is used to filter data from an existing RowSet. The filter will skip records that don't match the criteria specified in the filter when a next() is used on the RowSet.  
JoinRowSetImpl - This is used to simulate a SQL join command between two or more RowSet objects.  

Sangram Keshari sahu

• Jul 16th, 2005

 

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PChal

• Aug 11th, 2005

 

A RowSet can be * connected * or *disconnected* 
 
A *disconnected* rowset gets a connection to a data source in order to fill itself with data or to propagate changes in data back to the data source, but most of the time it does not have a connection open. While it is disconnected, it does not need a JDBC driver or the full JDBC API, so its footprint is very small. Thus a rowset is an ideal format for sending data over a network to a thin client.  
 
A connected RowSet is like a wrapper around the ResultSet. 
 
Implementation: 
 
A CachedRowSet class?a disconnected rowset that caches its data in memory; not suitable for very large data sets, but an ideal way to provide thin Java clients, such as a Personal Digital Assistant (PDA) or Network Computer (NC), with tabular data  
 
 
A JDBCRowSet class?a connected rowset that serves mainly as a thin wrapper around a ResultSet object to make a JDBC driver look like a JavaBeans component  
 
 
A WebRowSet class?a connected rowset that uses the HTTP protocol internally to talk to a Java servlet that provides data access; used to make it possible for thin web clients to retrieve and possibly update a set of rows

satish

• Aug 23rd, 2005

 

FilteredRowSetImpl - This is used to filter data from an existing RowSet. The filter will skip records that don't match the criteria specified in the filter when a next() is used on the RowSet. 
 
As per my understanding, If the Rowset contains a set of rows. If we want to remove some of the rows from the existing Rowset then we may use this Filter concept. Is it correct? If not Could you please explain and provide one example

TRK

• Aug 24th, 2005

 

batch update is a set of multiple update statements that is submitted to the database for processing as a batch. Sending multiple update statements to the database together as a unit can, in some situations, be much more efficient than sending each update statement separately. This ability to send updates as a unit, referred to as the batch update facility, is one of the features provided with the JDBC 2.0 API.

Rama devi Avirneni

• Sep 5th, 2005

 

Result set is not serialized. 
Row set is serialized. 
 
we ca serialize any class by implementing serialize interface.

navnish.sharma@gmail.com

 Profile Answers by navnish.sharma@gmail.com 

• Sep 19th, 2005

 

RowSet

 

The interface that adds support to the JDBC API for the JavaBeans^TM component model. A rowset, which can be used as a JavaBeans component in a visual Bean development environment, can be created and configured at design time and executed at run time.

The RowSet interface provides a set of JavaBeans properties that allow a RowSet instance to be configured to connect to a JDBC data source and read some data from the data source. A group of setter methods (setInt, setBytes, setString, and so on) provide a way to pass input parameters to a rowset's command property. This command is the SQL query the rowset uses when it gets its data from a relational database, which is generally the case.

The RowSet interface supports JavaBeans events, allowing other components in an application to be notified when an event occurs on a rowset, such as a change in its value.

The RowSet interface is unique in that it is intended to be implemented using the rest of the JDBC API. In other words, a RowSet implementation is a layer of software that executes "on top" of a JDBC driver. Implementations of the RowSet interface can be provided by anyone, including JDBC driver vendors who want to provide a RowSet implementation as part of their JDBC products.

A RowSet object may make a connection with a data source and maintain that connection throughout its life cycle, in which case it is called a connected rowset. A rowset may also make a connection with a data source, get data from it, and then close the connection. Such a rowset is called a disconnected rowset. A disconnected rowset may make changes to its data while it is disconnected and then send the changes back to the original source of the data, but it must reestablish a connection to do so.

ResultSet

A table of data representing a database result set, which is usually generated by executing a statement that queries the database.

A ResultSet object maintains a cursor pointing to its current row of data. Initially the cursor is positioned before the first row. The next method moves the cursor to the next row, and because it returns false when there are no more rows in the ResultSet object, it can be used in a while loop to iterate through the result set.

A default ResultSet object is not updatable and has a cursor that moves forward only. Thus, you can iterate through it only once and only from the first row to the last row. It is possible to produce ResultSet objects that are scrollable and/or updatable. The following code fragment, in which con is a valid Connection object, illustrates how to make a result set that is scrollable and insensitive to updates by others, and that is updatable. See ResultSet fields for other options.

guptach

 Profile Answers by guptach 

• Sep 22nd, 2005

 

A ResultSet maintains a connection to a database and because of that it can't be serialized and also we cant pass the Resultset object from one class to other class across the network.

RowSet is a disconnected, serializable version of a JDBC ResultSet and also the RowSet extends the ResultSet interface so it has all the methods of ResultSet. The RowSet can be serialized because it doesn't have a connection to any database and also it can be sent from one class to another across the network.

From the above answer it seems that RowSet is far better than ResultSet. Ofcourse it is correct but there are some situations where we need to use ResultSet only.

For example when we are querying the database using the ResultSet object, as it is connected to the database until the object is open and it does not contain all the data from your query. Since it has a connection to the database, when you run the next() method if the ResultSet needs more data it can go to the database and get it. The RowSet can't do that since it isn't connected to the database so it must load and hold all the data from your query as soon as you run the execute() method. If your query returns a lot or rows you could encounter very slow processing and out of memory errors. However, if the number of rows to be returned is a reasonable number then a RowSet can be used.

sudhakar

• Oct 15th, 2005

 

If the connection is alive, then only the values remain in a ResultSet, where as in RowSet,once we get the results connection need not be alive. 

Sekhar

• Mar 15th, 2012

 

ResultSet rs; where rs is treat like a cursor to a database.if the connection is alive then only we can retrieve the information through resultset object.

RowSet rs;We can retrieve data through rowset object with out depending upon the connection is alive or not.