updating & deleted records in rms

[jselvakumar26071988]

public void update_function(String add_name,String add_no,String blood,String delete_id)
{
try{
recordstore=RecordStore.openRecordStore("bloodbank",false);
byte outputrecord[]= recordstore.getRecord(Integer.parseInt(delete_id));
ByteArrayOutputStream outputstream_bytearray=new ByteArrayOutputStream();
DataOutputStream outputstream_data=new DataOutputStream(outputstream_bytearray);
outputstream_data.writeUTF(blood);
outputstream_data.writeUTF(add_name);
outputstream_data.writeUTF(add_no);
outputstream_data.flush();
outputrecord=outputstream_bytearray.toByteArray();
recordstore.setRecord(Integer.parseInt(delete_id), outputrecord, 0, outputrecord.length);
outputstream_bytearray.close();
outputstream_data.close();
}
catch(Exception e)
{

}
finally
{
try{
recordstore.closeRecordStore();


}
catch(Exception e)
{

}
}
}
public void delete_function(String delete_id)
{
try{
recordstore=RecordStore.openRecordStore("bloodbank",false);
recordstore.deleteRecord(Integer.parseInt(delete_id));
}
catch(Exception e)
{

}
finally
{
try{
recordstore.closeRecordStore();


}
catch(Exception e)
{

}
}
}




i have prob in updating and deleting.....no changes is seen.....

[grahamhughes]

What device are you doing this on?

I'd recommend you pass the ID around as an int, not a String.

Also, you are silently ignoring any and all exceptions... if the runtime is trying to tell you what went wrong, you won't find out.

Avoid using a non-local variable to hold the record store reference.

Code like this is much easier to work with:

void deleteRecord(int id) throws RecordStoreException {
    RecordStore rs = RecordStore.openRecordStore(RECORD_STORE_NAME);
    try {
        rs.deleteRecord(id);
    } finally {
        rs.closeRecordStore();
    }
}

[jselvakumar26071988]

im geeting id from text field...so it possible to do with string and den converting to int.....whats wrong with the above code

[grahamhughes]

I don't have a magic power to tell you what's wrong. You need to give me some clues.

What device are you using?

Why is recordstore not local? I suggest you use local variables for this.

Don't pass the String ID to this code. Validate the ID on input, and convert it to an int then.

[raj_J2ME]

im geeting id from text field...so it possible to do with string and den converting to int.....whats wrong with the above code

Hi,
Well thats a problem, most of the time developers has to face...
However its not too tuff that it cant be done...there are so many demo on google ..you can find the same..
Have you read some tutorials on it..

Updating a particular record involves getting a handle for that record and setting new information.

public int getRecord(int recordId, byte[] buffer, int offset) returns the data stored in the given record in the byte array represented by buffer. public byte[] getRecord(int recorded) returns a copy of the data represented by recordId. public void setRecord(int recordId, byte[] newData, int offset, int numBytes) sets new information, a stream of bytes (newData) with offset as its starting index and numBytes as its length, at the record location represented by recordId.

Listing 5. Update a record

String newappt = "update record";
Byte data = newappt.getBytes();
Rs.setRecord(1, data, 0, data.length());


Deleting records

The MIDlet invokes the deleteRecord() method to delete a record from the record store.

public void deleteRecord(int recordId) deletes the record represented by recordId. The recordId for this record is not subsequently reused.


Rs.deleteRecord(1);

Here are some link
http://developers.sun.com/mobility/m...s/databaserms/
Hope this helps you,

[jselvakumar26071988]

i tried.....its mixed data type....dunno how to delete and update....can anyone rectify my code........

[jselvakumar26071988]

both working...thanks guys

[grahamhughes]

I can't help you if you won't give me any more information.

[jselvakumar26071988]

now the prob again arises.....adding/deleting is not synchronised.....though after deletion if add new values i get the deleted values too...i know record enumeration is the prob.i tried keptupdated()...

[jselvakumar26071988]

now the prob again arises.....adding/deleting is not synchronised.....though after deletion if add new values i get the deleted values too...i know record enumeration is the prob.i tried keptupdated()...

[raj_J2ME]

Hi,
Well, can you share that what exactly you are looking for??
Which functionalities you want o implement..like this no one can help you,
Now nothing is clear that what is happening and what not..
Thanks,

[jselvakumar26071988]

same rms searching complete reference code....but its i/p are dynamic.for eg
1.selva
operation:deleted record(1);
o/p:no record


operation:added surya
o/p:1.selva
2.surya

i have used recordenmeration...i think ,it doesn't rebuild its internal id.

[jselvakumar26071988]

In reference to "j2me complete reference:rms mixed datatype"
writeutf is used for strings.

now the prob is,if i have two strings(dynamic) whether i have to use writeutf & readutf two times ?

[grahamhughes]

Yes you do.

[raj_J2ME]

Hi,
You have the two string variables ..to write in RMS...These must be having some values...

Just use simple method of the data writing--

-------------------- Writing -------------------------
@ open the RMS
@ have the string..
@ convert the same in bytes ..
@ add the bytes in RMS using addRecord().

try
{
recordstore = RecordStore.openRecordStore(
"myRecordStore", true );
}
catch (Exception error)
{
alert = new Alert("Error Creating",
error.toString(), null, AlertType.WARNING);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);
}
try
{
String outputData = "First Record";
byte[] byteOutputData = outputData.getBytes();
recordstore.addRecord(byteOutputData, 0,
byteOutputData.length);
}
catch ( Exception error)
{
alert = new Alert("Error Writing",
error.toString(), null, AlertType.WARNING);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);

------------------------- Reading -----------------------------
try
{
byte[] byteInputData = new byte[1];
int length = 0;
for (int x = 1; x <= recordstore.getNumRecords(); x++)
{
if (recordstore.getRecordSize(x) > byteInputData.length)
{
byteInputData = new byte[recordstore.getRecordSize(x)];
}
length = recordstore.getRecord(x, byteInputData, 0);
}
alert = new Alert("Reading", new String(byteInputData, 0,
length), null, AlertType.WARNING);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);


}
catch (Exception error)
{
alert = new Alert("Error Reading", error.toString(),
null, AlertType.WARNING);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);
}
try
{
recordstore.closeRecordStore();
}
catch (Exception error)
{
alert = new Alert("Error Closing", error.toString(),
null, AlertType.WARNING);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);
}
if (RecordStore.listRecordStores() != null)
{
try
{
RecordStore.deleteRecordStore("myRecordStore");
}
catch (Exception error)
{
alert = new Alert("Error Removing", error.toString(),
null, AlertType.WARNING);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);
}
}
}
Hope that these liens can help you,
Thanks,