Printable View
I am making a program to search the student detail by enterering the roll number.In this I want to do if the student of entered roll number doest not exist in databse then it should diaplay a dialogue box The student of that roll number does not exist.
I have used
if(rs.wasNull())
display the dialogue box
else
display the details
but in each case else is executing but if is not why it is?
Could you post the code relating to the assignment of the rs (ResultSet I assume)?
No need for the whole code block, just the bits relating to 'rs'.
Yes its result set
while(res.next())
{
String name=res.getString(1);
String city=res.getString(2);
String class1=res.getString(3);
if(res.wasNull())
{
tf1.setText("Does nOt EXist");
tf2.setText("Does nOt EXist");
tf3.setText("Does nOt EXist");
}
else
{
tf1.setText(name);
tf2.setText(city);
tf3.setText(class1);
}
}
Read the API documentation for the ResultSet.wasNull() method; it doesn't do what you hope it does; hint, if there is no ResultSet.next() element no student matched the criteria ...
kind regards,
Jos
@JosAH could u please tell me what should i use and i have read wasNull method but i can not get its use could u please tell me this also..
Thanx
If no row exists in the database for the given sql query, there doesn't exist a ResultSet.next() (i.e. that method returns false after the first call) so your while loop body is never entered; you should display your notification in that case.Quote:
Originally Posted by juhiswt
kind regards,
Jos
@JosAH thanx alot ...
I think your problem is quite similar to my problem:
http://www.java-forums.org/database/...return-same-i-
need-refresh.html
There is bug on resultset
Have you read this thread? What the OP described most certainly wasn't a bug on the ResultSet part. b.t.w. the bugbase is full of bugs that aren't bugs ...Quote:
Originally Posted by RichersooN
kind regards,
Jos