Develop Reference

Looking for the optimization of the below code

I have found below code buggy as it degrades the performance of extjs3 grid, i am looking for possibilities of optimization at query or code level, as per my analysis, if we extract out the query there are two nested inner queries which are responding slow, in addition, the code inside while loop trying to find the unique id, can't we have distinct in query, or joins rather than inner queries.
Please suggest me the best practice to follow in order to achieve optimization.
public boolean isSCACreditOverviewGridVisible(String sessionId) {
Connection conn = null;
ResultSet rs = null;
PreparedStatement ps = null;
boolean result = false;
try {
CommonUtility commUtil = new CommonUtility();
List<String> hmIds = new ArrayList<String>();
Map<String, String> tmStockMap = new TreeMap<String, String>();
Set<String> setRecentCertificate = new HashSet<String>();
String managerAccountId = sessionInfo.getMembershipAccount();
String stockQuery = " select memberId , RootCertficateId from stockposition sp where sp.stocktype = 'TR' and sp.memberId "
+ " IN ( select hm2.accountId from "
DATALINK
+ ".holdingmembers hm2 "
+ " where hm2.holdingId = ( select holdingId from "
DATALINK
+ ".holdingmembers hm1 where hm1.accountId = ? )) "
+ " order by sp.createdDate desc ";
conn = getChildDBConnection();
if (null != conn) {
ps = conn.prepareStatement(stockQuery);
ps.setString(1, managerAccountId);
rs = ps.executeQuery();
if (null != rs) {
while (rs.next()) {
String memberId = rs.getString("memberId");
String rootCertficateId = rs
.getString("RootCertficateId");
if (tmStockMap.containsKey(rootCertficateId)) {
continue;
}
hmIds.add(memberId);
tmStockMap.put(rootCertficateId, memberId);
}
}
rs.close();
ps.close();
if (null != hmIds && !hmIds.isEmpty()) {
String inIds = commUtil.getInStateParam(hmIds);
String mostRecentLicense = "Select RootCertificateId , memberaccountid from "
+ OctopusSchema.octopusSchema
+ ".certificate c where c.memberaccountid IN ("
+ inIds
+ ") and c.isrootcertificate=0 and c.certificationstatusid > 1 order by c.modifieddate desc";
ps = conn.prepareStatement(mostRecentLicense);
rs = ps.executeQuery();
if (null != rs) {
while (rs.next()) {
String rootCertficateId = rs
.getString("RootCertificateId");
String memberaccountid = rs
.getString("memberaccountid");
if (setRecentCertificate.contains(memberaccountid)) {
continue;
}
setRecentCertificate.add(memberaccountid);
if (tmStockMap.containsKey(rootCertficateId)) {
result = true;
break;
}
}
}
rs.close();
ps.close();
} else {
result = false;
}
}
} catch (Exception e) {
LOGGER.error(e);
} finally {
closeDBReferences(conn, ps, null, rs);
}
return result;
}
QUERY:
select RootCertficateId,memberId from stockposition sp where sp.stocktype = 'TR' and sp.memberId
IN ( select hm2.accountId from
DATALINK.holdingmembers hm2
where hm2.holdingId = ( select holdingId from
DATALINK.holdingmembers hm1 where hm1.accountId = '4937' ))
order by sp.createdDate DESC;

One quick approach would be a substition of your IN by EXISTS. If your inner queryes return a lot of rows, it would be a lot more efficient. It depends if your subquery returns a lot of results.
SQL Server IN vs. EXISTS Performance

Declaring Scalar variables on sql insert using java

I'm trying to insert into a database, but with the added bonus of checking if there is duplicate data based on 5 fields.
For example I want to insert a line of data but for every ID, it will check 4 other fields, if all 5 fields match I do not want to insert. Other than that, an insert.
So far I have made the sql statement. I tried my query on a database dummy to see if it works and it does but when I run it in java with all the prepared statements, it gives me an error that says "Must declare the scalar variable". Here is my code and I do not know where to declare or what I must declare. Does it depend on the configuration of the database?
System.out.println("connection created successfully using properties file");
PreparedStatement pstmt2 = null;
PreparedStatement pstmt3 = null;
PreparedStatement pstmt5 = null;
PreparedStatement pstmt6 = null;
ResultSet rs = null;
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(
"C:\\Users\\darroyo\\Documents\\pruebasx.txt"));
} catch (FileNotFoundException e1) {
logger.error(e1.getMessage());
}
String line = null;
try {
line = reader.readLine();
} catch (IOException e1) {
logger.error(e1.getMessage());
}
String query = " insert into FRONTMC.HECHO (folio_hecho, folio_orden,"
+ "clave_sentido, titulos_hecho, precio, importe, liquidacion, contraparte, id_estatus, isin, contrato,"
+ "secondary_exec_id, exec_id, F11_ClOrdID, fecha_recepcion, fecha_sentra,emisora,serie)"
+ " select ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,convert(varchar(30),cast(? as datetime),120),convert(varchar(30),cast(? as datetime),120),?,?"
+" from FRONTMC.HECHO WHERE NOT EXISTS (SELECT * FROM FRONTMC.HECHO WHERE ISIN = ?"
+ "AND EMISORA = ? AND SERIE = ? AND CLAVE_SENTIDO = ? AND SECONDARY_EXEC_ID =?";
PreparedStatement preparedStmt = null;
try {
preparedStmt = con.prepareStatement(query);
} catch (SQLException e1) {
logger.error(e1.getMessage());
}
Map<Integer,String> hm1 = new HashMap<Integer,String>();
try {
do {
try{
String[] tokens = line.split("");
for (int i = 0; i != tokens.length; i++) {
int dataIndex = tokens[i].indexOf('=') + 1;
String data = tokens[i].substring(dataIndex);
hm1.put(new Integer(i),data);
}
String query2 = "select emisora from FRONTMC.EMISORA_CUSTODIO_SIGLO where isin = ?";
String query5 = " insert into FRONTMC.HECHO (emisora)"
+ " values ( ?)";
pstmt2 = con.prepareStatement(query2);
pstmt5 = con.prepareStatement(query5);
String query3 = "select serie from FRONTMC.EMISORA_CUSTODIO_SIGLO where isin = ?";
String query6 = " insert into FRONTMC.HECHO (emisora)"
+ " values ( ?)";
pstmt3 = con.prepareStatement(query3); // create a statement
pstmt6 =con.prepareStatement(query6);
setParameterString(preparedStmt,1, hm1.get(23));
setParameterString(preparedStmt,2, hm1.get(19));
setParameterString(preparedStmt,3, hm1.get(15));
setParameterString(preparedStmt,4, hm1.get(30));
setParameterString(preparedStmt,5, hm1.get(16));
setParameterString(preparedStmt,6, hm1.get(18));
setParameterString(preparedStmt,7, hm1.get(8));
setParameterString(preparedStmt,8, hm1.get(33));
setParameterString(preparedStmt,9, hm1.get(27));
setParameterString(preparedStmt,10, hm1.get(17));
setParameterString(preparedStmt,11, hm1.get(26));
setParameterString(preparedStmt,12, hm1.get(23));
setParameterString(preparedStmt,13, hm1.get(10));
setParameterString(preparedStmt,14, hm1.get(14));
SimpleDateFormat sdf1 = new SimpleDateFormat("yyyyMMdd");
SimpleDateFormat sdf2 = new SimpleDateFormat("dd/MM/yyyy");
String ds2 = null;
ds2 = sdf2.format(sdf1.parse(hm1.get(6)));
String newfecha1 = ds2;
setParameterString(preparedStmt,15, newfecha1);
SimpleDateFormat sdf3 = new SimpleDateFormat("yyyyMMdd");
SimpleDateFormat sdf4 = new SimpleDateFormat("dd/MM/yyyy");
String ds4 = null;
ds4 = sdf4.format(sdf3.parse(hm1.get(6)));
String newfecha3 = ds4;
setParameterString(preparedStmt,16, newfecha3);
pstmt2.setString(1, hm1.get(17));
rs = pstmt2.executeQuery();
while (rs.next()) {
String emisora = rs.getString(1);
pstmt5.setString(1,emisora);
setParameterString(preparedStmt,17, emisora);
pstmt3.setString(1, hm1.get(17));
rs = pstmt3.executeQuery();
while (rs.next()) {
String serie = rs.getString(1);
pstmt6.setString(1,serie);
System.out.println(serie);
setParameterString(preparedStmt,18, serie);
setParameterString(preparedStmt,19, hm1.get(17));
setParameterString(preparedStmt,20, emisora);
setParameterString(preparedStmt,21, serie);
setParameterString(preparedStmt,22, hm1.get(15));
setParameterString(preparedStmt,23, hm1.get(23));
preparedStmt.execute();
}
}}catch(Exception ab){
new Thread(new Runnable(){
#Override
public void run(){
errorcon2();
}
}).start();
logger.error(ab.getMessage());
System.out.println(ab.getMessage());
ab.printStackTrace();
}
}while ((line = reader.readLine()) != null);}
catch(Exception a){
logger.error(a.getMessage());
}
new Thread(new Runnable(){
#Override
public void run(){
exitomsj();
}
}).start();
Here is the exception I get: Mistranslation it is not scalable, it is scalar.
com.microsoft.sqlserver.jdbc.SQLServerException: Debe declarar la variable escalar "#P18AND".
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(SQLServerException.java:217)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.getNextResult(SQLServerStatement.java:1655)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.doExecutePreparedStatement(SQLServerPreparedStatement.java:440)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement$PrepStmtExecCmd.doExecute(SQLServerPreparedStatement.java:385)
at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:7505)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLServerConnection.java:2445)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeCommand(SQLServerStatement.java:191)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeStatement(SQLServerStatement.java:166)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.execute(SQLServerPreparedStatement.java:367)
at swt.swtapp2$2.mouseDown(swtapp2.java:488)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:193)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4418)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1079)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4236)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3824)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:818)
at org.eclipse.jface.window.Window.open(Window.java:794)
at swt.swtapp2.main(swtapp2.java:610)

You are missing a space.
+ "AND EMISORA = ? AND ...
should be
+ " AND EMISORA = ? AND ...

how to insert object to h2

I've read H2 docs about storing objects in database. There is special SQL type OTHER and methods setObject and getObject. I've tried this code:
PreparedStatement statement = null;
try {
statement = connection.prepareStatement("CREATE TABLE PUBLIC.foo (name VARCHAR(64) NOT NULL, data OTHER NULL);");
statement.execute();
} finally {
statement.close();
}
statement = null;
try {
statement = connection.prepareStatement("INSERT INTO PUBLIC.foo (name, data) VALUES(?,?);");
statement.setString(1, "lololo");
statement.setObject(2, new String[]{"foo", "bar"});
statement.execute();
}finally {
statement.close();
}
But I've got the exception:
org.h2.jdbc.JdbcSQLException: Ше�тнадцатирична� �трока �одержит неше�тнадцатиричные �имволы: "(foo, bar)"
Hexadecimal string contains non-hex character: "(foo, bar)"; SQL statement:
INSERT INTO PUBLIC.foo (name, data) VALUES(?,?) -- (?1, ?2) [90004-191]
What is wrong?

I believe this is what you were look for (Even I was).
You just need to create a column in your table with type as 'other'.
See 'create table testobj2(obj other)'
Look at my Sample code :
static String DB_DRIVER = "org.h2.Driver";
static String DB_CONNECTION = "jdbc:h2:./test2";
static String DB_USER = "";
static String DB_PASSWORD = "";
public static void benchmarkH2Inserts() {
try {
Class.forName(DB_DRIVER);
Connection dbConnection = DriverManager.getConnection(DB_CONNECTION, DB_USER, DB_PASSWORD);
String createQry = "create table testobj2(obj other)";
String insertQuery = "insert into testobj2(obj) values(?)";
String selectQuery = "select * from testobj2";
// dbConnection.setAutoCommit(false);
dbConnection.prepareStatement(createQry).executeUpdate();
long lStartTime = System.nanoTime();
for(int i=0; i<10000; i++) {
dbConnection.setAutoCommit(false);
CloudElement_Circuit obj = new CloudElement_Circuit();
obj.setNrm8DesignId(1230L);
PreparedStatement preparedStatement = dbConnection.prepareStatement(insertQuery);
preparedStatement.setObject(1,obj);
preparedStatement.execute();
dbConnection.commit();
}
long lEndTime = System.nanoTime();
long output = lEndTime - lStartTime;
System.out.println("benchmarkH2Inserts() : Elapsed time in nanoseconds: " + output);
System.out.println("benchmarkH2Inserts() : Elapsed time in milliseconds: " + output / 1000000);
//Selecting
PreparedStatement preparedStatement = dbConnection.prepareStatement(selectQuery);
ResultSet rs = preparedStatement.executeQuery();
while(rs.next()) {
CloudElement_Circuit obj = (CloudElement_Circuit) rs.getObject("obj");
System.out.println("Fetched Object : " + obj.getNrm8DesignId());
}
dbConnection.close();
} catch (Exception e) {
e.printStackTrace();
}
}
Note that 'CloudElement_Circuit' is a Serialized class.
Look at 'OTHER Type' here : http://www.h2database.com/html/datatypes.html
H2 Example : https://www.javatips.net/blog/h2-database-example

Try this approach
List<String> genre = new ArrayList<String>();
String comma="";
StringBuilder allGenres = new StringBuilder();
for (String g: genre) {
allGenres.append(comma);
allGenres.append(g);
comma = ", ";
}
Then you can pass it like this
preparedStmt.setString (2, allGenres.toString());

How to generalize resultset queries?

at the moment I'm working on a script that reads several values from different tables of one database. Every time I start a request, I have to open a statement and create a new resultset which leads to horrible, repetative code. What would be a good way of generalizing this and how can this be done?
Some elements from my code. At the moment there's just one statement and the closing has to be inserted. One of the primary reasons I ask this question.
public static void main(String[] args) throws Exception
{
Connection c = null;
Statement stmt = null;
try
{
//set up database connection
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:/nfs/home/mals/p/pu2002/workspace/Database2");
c.setAutoCommit(false);
stmt = c.createStatement();
//end
//get task id to work with
String Task_id = null;
if(args.length != 0) //if an argument was passed, Task_id will be the first element of the array args (arguments)
{
Task_id = args[0];
}
else if(args.length == 0) //if no arguments were passed, the highest number in the column id from tasks_task will be selected and set as Task_id
{
ResultSet TTask_id = stmt.executeQuery("SELECT max(id) FROM tasks_task");
int t_id = TTask_id.getInt(1);
Task_id = String.valueOf(t_id);
TTask_id.close();
}
//end
//get solution IDs from taks_ids
ArrayList<Integer> List_solIDs = new ArrayList<Integer>(); //create an empty array list
ResultSet SSolution_task_id = stmt.executeQuery("SELECT id FROM solutions_solution WHERE task_id ="+Task_id + " AND final = 1;"); //Sqlite3-Ausdruck SELECT..., Task IDs verändern pro Aufgabe - "SELECT * FROM solutions_solution where task_id ="+Task_id +";"
while (SSolution_task_id.next()) //loops through all elements of SSolution_task_id
{
List_solIDs.add(SSolution_task_id.getInt("id")); //adds all elements of the resultset SSolution_task_id to the list List_solIDs
}
SSolution_task_id.close();
//end
//get logs according to content type
int count = List_solIDs.size();
String log_javaBuilder = null;
List<String> log_JunitChecker = new ArrayList<String>();
for (int i = 0; i < count; i++)
{
boolean sol_id_valid = false;
String solID = String.valueOf(List_solIDs.get(i));
try
{
ResultSet AAttestation_sol_id = stmt.executeQuery("SELECT * FROM attestation_attestation WHERE solution_id =" +solID+";");
int Returned = AAttestation_sol_id.getInt("final_grade_id");
}
catch(Exception e)
{
sol_id_valid = true;
}
if(sol_id_valid ==true)
{
try
{
ResultSet CCresult_javaBuilder = stmt.executeQuery("SELECT log FROM checker_checkerresult WHERE solution_id = " +solID+ " AND content_type_id = 22;"); //"SELECT id FROM checker_checkerresult where solution_id = " +List_solIDs.get(i)+ ";"
log_javaBuilder = CCresult_javaBuilder.getString("log");
CCresult_javaBuilder.close();
ResultSet CCresult_Junit_checker = stmt.executeQuery("SELECT log FROM checker_checkerresult WHERE solution_id = " +solID+ " AND content_type_id = 24;");
while (CCresult_Junit_checker.next())
{
log_JunitChecker.add(CCresult_Junit_checker.getString("log"));
}
CCresult_Junit_checker.close();
}
catch (Exception e)
{
log_JunitChecker.add(null);
}
//end
All types of potential improvements will be welcome.
P.S.: Tried googling.

Seems you want to look at using some ORM layer e.g. http://hibernate.org/orm/
What you're looking for is probably a higher-level layer which
abstracts you from the underlying lower-level JDBC type of coding.

Better than writing generic method by yourself it is always better to use some framework, There are many JPA implementations out there which solve not only this issue but also takes care of multiple persistence layer boiler plate code. Start JPA from Here. You can also use Spring JDBC template as well to solve problem mentioned above Spring JDBC Documentation.
Now, if you really don't want any framework dependency and finish this code quite fast, You can define your own JDBCTemplate class which takes query and parameter map and return ResultSet. This class can handle open connection, query execution and closing connection etc.

What if you try to use generics on methods? this is a quick example, just for illustration, you must improve all this :)
resource: official docs
public static <T> List<T> getSingleValueList(ResultSet rs, Class<T> clazz, String colName) throws Exception {
ArrayList<T> list = new ArrayList<T>();
while (rs.next()) {//loops through all elements of generic list
list.add((T) rs.getObject(colName)); //adds all elements of the resultset rs to the list
}
rs.close();
return list;
}
public static <T> T getSingleValue(ResultSet rs, Class<T> clazz, String colName) throws Exception {
try {
if (rs.next()) {//loops through all elements of generic list
return (T) rs.getObject(colName);
} else {
throw new Exception("no value found.");
}
} finally {
rs.close();
}
}
public static void main(String[] args) throws Exception {
Connection c = null;
Statement stmt = null;
try {
//set up database connection
Class.forName("org.sqlite.JDBC");
c = DriverManager.getConnection("jdbc:sqlite:/nfs/home/mals/p/pu2002/workspace/Database2");
c.setAutoCommit(false);
stmt = c.createStatement();
//end
//get task id to work with
String Task_id = null;
if (args.length != 0) //if an argument was passed, Task_id will be the first element of the array args (arguments)
{
Task_id = args[0];
} else if (args.length == 0) //if no arguments were passed, the highest number in the column id from tasks_task will be selected and set as Task_id
{
ResultSet TTask_id = stmt.executeQuery("SELECT max(id) FROM tasks_task");
int t_id = TTask_id.getInt(1);
Task_id = String.valueOf(t_id);
TTask_id.close();
}
//end
//get solution IDs from taks_ids
ResultSet SSolution_task_id = stmt.executeQuery("SELECT id FROM solutions_solution WHERE task_id =" + Task_id + " AND final = 1;"); //Sqlite3-Ausdruck SELECT..., Task IDs verändern pro Aufgabe - "SELECT * FROM solutions_solution where task_id ="+Task_id +";"
List<Integer> List_solIDs = getSingleValueList(SSolution_task_id, Integer.class, "id"); //create an empty array list
//end
//get logs according to content type
int count = List_solIDs.size();
String log_javaBuilder = null;
List<String> log_JunitChecker = new ArrayList<String>();
List<String> tmplog_JunitChecker;
for (int i = 0; i < count; i++) {
boolean sol_id_valid = false;
String solID = String.valueOf(List_solIDs.get(i));
try {
ResultSet AAttestation_sol_id = stmt.executeQuery("SELECT * FROM attestation_attestation WHERE solution_id =" + solID + ";");
Integer Returned = getSingleValue(AAttestation_sol_id, Integer.class, "final_grade_id");
} catch (Exception e) {
sol_id_valid = true;
}
if (sol_id_valid == true) {
try {
ResultSet CCresult_javaBuilder = stmt.executeQuery("SELECT log FROM checker_checkerresult WHERE solution_id = " + solID + " AND content_type_id = 22;"); //"SELECT id FROM checker_checkerresult where solution_id = " +List_solIDs.get(i)+ ";"
log_javaBuilder = getSingleValue(CCresult_javaBuilder, String.class, "log");
ResultSet CCresult_Junit_checker = stmt.executeQuery("SELECT log FROM checker_checkerresult WHERE solution_id = " + solID + " AND content_type_id = 24;");
tmplog_JunitChecker = getSingleValueList(CCresult_Junit_checker, String.class, "log");
log_JunitChecker.addAll(tmplog_JunitChecker);
} catch (Exception e) {
log_JunitChecker.add(null);
}
//end
}
}
} catch (Exception eeee) {
//handle it
}
}
I hope I gave you a light.
Anyway, frameworks in almost all cases help a lot.

Result set returns 3 rows but i am only able to print 2?

The code below gets the information i require from my database but is not printing out all of the information. Firstly i know it is getting all of the correct information from the table because i have tried the query in sql developer.
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
conn = getConnection();
String query = "SELECT menu.menu_id, menu_title, dish.dish_id, dish_name, dish_description, dish_price, menu.week_no "
+ "FROM menu, dish, menu_allocation "
+ "WHERE menu.active = '1' "
+ "AND menu.menu_id = menu_allocation.menu_id "
+ "AND dish.dish_id = menu_allocation.dish_id "
+ "AND menu.week_no IN (09, 10, 11)";
stmt = conn.createStatement();
rs = stmt.executeQuery(query);
MenuList list = null;
while (rs.next()) {
list = new MenuList(rs);
System.out.println(rs.getRow());
}
for (int pos = 0; pos < list.size(); pos++) {
Menu menu = list.getMenuAt(pos);
System.out.println(menu.getDescription());
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
rs.close();
stmt.close();
conn.close();
} catch (SQLException e) {
}
}
}
The output from the terminal is as follows:
3 //Number of rows
Fish and Chips //3rd row
Chocolate Cake //2nd row
//Here should be 1st row
BUILD SUCCESSFUL (total time: 2 seconds)
Even though it says there are three rows it has only printed the two. Can anybody see if there is a problem with the above?

It's hard to be sure without seeing the code for the MenuList class but I don't think you need to loop over the ResultSet as MenuList does that for you.
As the MenuList constructor takes the ResultSet in rs as a parameter it probably loops over the ResultSet to create its entries. As you've already called rs.next() in the while of your loop the MenuList misses the first result.
I think you should replace all this:
MenuList list = null;
while (rs.next()) {
list = new MenuList(rs);
System.out.println(rs.getRow());
}
With:
MenuList list = new MenuList(rs);

I would suggest you use a debugger so you understand what your progam is doing.
You appear to be only keeping the last row loaded, so while you have 3 rows, you only keep the last. It appears you are getting two values from the last row.

public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
conn = getConnection();
String query = "SELECT menu.menu_id, menu_title, dish.dish_id, dish_name, dish_description, dish_price, menu.week_no "
+ "FROM menu, dish, menu_allocation "
+ "WHERE menu.active = '1' "
+ "AND menu.menu_id = menu_allocation.menu_id "
+ "AND dish.dish_id = menu_allocation.dish_id "
+ "AND menu.week_no IN (09, 10, 11)";
stmt = conn.createStatement();
rs = stmt.executeQuery(query);
MenuList[3] list = null;
int idx = 0; //Add index
while (rs.next()) {
list[idx] = new MenuList(rs); //use index
idx++; //increment index
System.out.println(rs.getRow());
}
for (int pos = 0; pos < list.size(); pos++) {
Menu menu = list.getMenuAt(pos);//Don't know that
//get menu by index
System.out.println(menu.getDescription());
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
rs.close();
stmt.close();
conn.close();
} catch (SQLException e) {
}
}
}