Get one record instead of List of records

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teser3@hotmail.com - 10 Dec 2007 00:57 GMT

I have a class that fetches a record but dont think I need to use List
object because I am fetching one record and not an array of records.
Please advise the best way to change the below class where I assume I
should use something different instead of List? Maybe HashMap? Not
sure how to do this?

public List getRecords(){
ResultSet rs = null;
Statement stmt = null;
Connection connection = null;

List rows = new ArrayList();

try
{
Class.forName("org.gjt.mm.mysql.Driver");
connection = DriverManager.getConnection("jdbc:mysql://
localhost/dbase?user=myname&password=thepassword");
stmt = connection.createStatement();
rs = stmt.executeQuery("SELECT * from user where userid =
10");

while(rs.next()){
RowBean row = new RowBean();
row.setFirstname(rs.getString("firstname"));
row.setLastname( rs.getString("lastname"));
rows.add(row);
.....

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Arne Vajhøj - 10 Dec 2007 01:07 GMT

> I have a class that fetches a record but dont think I need to use List
> object because I am fetching one record and not an array of records.
[quoted text clipped - 3 lines]
>
> public List getRecords(){

> List rows = new ArrayList();
> try
> {

> rs = stmt.executeQuery("SELECT * from user where userid = 10");
> while(rs.next()){
[quoted text clipped - 3 lines]
> rows.add(row);
> .....

Why not just return a RowBean ?

Arne

Reply to this Message

teser3@hotmail.com - 10 Dec 2007 01:37 GMT

> tes...@hotmail.com wrote:
> > I have a class that fetches a record but dont think I need to use List
[quoted text clipped - 20 lines]
>
> - Show quoted text -

Thanks,

It would be like this?

public RowBean getRecord(){
ResultSet rs = null;
Statement stmt = null;
Connection connection = null;

//List rows = new ArrayList();
RowBean row = new RowBean();

try
{
Class.forName("org.gjt.mm.mysql.Driver");
connection = DriverManager.getConnection("jdbc:mysql://
localhost/dbase?user=myname&password=thepassword");
stmt = connection.createStatement();
rs = stmt.executeQuery("SELECT * from user where userid =
10");

while(rs.next()){

row.setFirstname(rs.getString("firstname"));
row.setLastname( rs.getString("lastname"));
//rows.add(row);
}
.....

return row;

Reply to this Message

teser3@hotmail.com - 10 Dec 2007 01:40 GMT

Thanks,

Would it be like this?

public List getRecord(){
ResultSet rs = null;
Statement stmt = null;
Connection connection = null;

//List rows = new ArrayList();
RowBean row = new RowBean();

try
{
Class.forName("org.gjt.mm.mysql.Driver");
connection = DriverManager.getConnection("jdbc:mysql://
localhost/dbase?user=myname&password=thepassword");
stmt = connection.createStatement();
rs = stmt.executeQuery("SELECT * from user where userid =
10");

while(rs.next()){

row.setFirstname(rs.getString("firstname"));
row.setLastname( rs.getString("lastname"));
//rows.add(row);
}
.....
//after end of try block
return row;

Reply to this Message

Arne Vajhøj - 10 Dec 2007 02:15 GMT

> Would it be like this?
>
> public List getRecord(){

> RowBean row = new RowBean();

> rs = stmt.executeQuery("SELECT * from user where userid = 10");
>
> while(rs.next()){
> row.setFirstname(rs.getString("firstname"));
> row.setLastname( rs.getString("lastname"));
> }

> return row;

Yes. Except that you could use if instead of while when
you know there will be one row.

Arne

Reply to this Message

Lew - 10 Dec 2007 03:18 GMT

>> Would it be like this?
>>
[quoted text clipped - 14 lines]
> Yes. Except that you could use if instead of while when
> you know there will be one row.

Make sure to close the connection. A finally{} block is the place to do that.

It's also unnecessary to initialize every variable to null at the top of the
method. Just declare it and initialize it to its value in the moment when the
value becomes available.

You do not need to load the JDBC driver but once, not every time you run the
method. A static initializer is a good place for that.

Signature

Lew

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Arne Vajhøj - 10 Dec 2007 03:34 GMT

>>> Would it be like this?
>>>
[quoted text clipped - 24 lines]
> You do not need to load the JDBC driver but once, not every time you run
> the method. A static initializer is a good place for that.

That is some very good points !

Arne

Reply to this Message

teser3@hotmail.com - 12 Dec 2007 00:39 GMT

Thanks, is this an example of DTO (Data Transfer Object)??

public RowBean getRecord(){

...
RowBean row = new RowBean();

try
{
....

if(rs.next()){
row.setFirstname(rs.getString("firstname"));
row.setLastname( rs.getString("lastname"));
//rows.add(row);
}
//catch and finally blocks here

return row;

Reply to this Message

Get one record instead of List of records

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