Balaguru Krish

In order to know the column name which is the primary key , we can use
USER_CONS_COLUMNS table.

Example:

SELECT COLUMN_NAME FROM USER_CONS_COLUMNS WHERE CONSTRAINT_NAME = 'EMP_PRIMARY_KEY'

Originally posted by Shobana Sukumar:
which table can i refer to find the primary key of a table?i need a tablename to be refered other than the desc command as i hav to access the table name's primary key value from a code....

In order to know the primary keys of a table,we have a table called USER_CONSTRAINTS.

Example :

select * from user_constraints where table_name = 'EMP' and constraint_type = 'P'

For iterating a resultset , why there is a need for a connection object after the resultset is being returned by executeQuery(sqlQuery) ?

ResultSet rs = stmt.executeQuery("select * from emp");
con.close();
while( rs.next() )
{

}

It throws an Exception .
Why?

I do'nt want the browser to remember the values.
Can we do it progrmmatically ?

I have a set of text fields in a html page.After entering values in the text fields , i submit it . After doing certain operations , The page is logged out.

If we go to the same page again , if we enter starting with alphabet which we previously entered , the value entered previously is shown.

Similar to the username being retained in the case of rediff or yahoo pages.

Do we have any solution for this progrmmatically?
[ November 22, 2005: Message edited by: Bear Bibeault ]

What is the difference between Comparable and Comparator interfaces?
At what situation these interfaces are used?

I am preparing for SCJP and i have the following doubt.

Consider the following code :

public class Test
{
public static void main(String [] args)
{
SuperTest st = new SubTest();
st.testMethod(10);
}
}

class SuperTest
{
public void testMethod(int a)
{
System.out.println("\n Test Method in Super Test Class ");
}
}

class SubTest extends SuperTest
{
public void testMethod(final int a)
{
System.out.println("\n Test Method in SubTest Class ");
}
}

Whether the testMethod in SuperTest is overloaded or overriden in SubTest ?

Sorry For Previous Reply, I did not add my reply to it.

Problem lies with statement -> this(f);

The problem is we cannot refer to an instance while invoking explicit
constructor.

Hence it must be replaced with this(<constant-value> ;

Originally posted by bhadule bhadule:
Hello Ranchies,
can anybody plz explain me why this bellow code is not getting compile?


public class Test19 {
float f;
Test19(){
this(f);
f = 3;
}
Test19(float f){
System.out.println(f);
}
public static void main(String args[]) {
Test19 t = new Test19();
}
}


Regards
Hrushi

Originally posted by bhadule bhadule:
Hello Ranchies,
can anybody plz explain me why this bellow code is not getting compile?


public class Test19 {
float f;
Test19(){
this(f);
f = 3;
}
Test19(float f){
System.out.println(f);
}
public static void main(String args[]) {
Test19 t = new Test19();
}
}


Regards
Hrushi