Re-using statement objects

Question

Hi,
I am new to jdbc and sql in Java. So this is my question.
If I want to to a select statement and depending on the result a second select, can I do this on the same statement object, or do I have to create a new one? And what about the resultset? Can you re-use this? And do you always close this statement after using it, or can you just close it when the program finishes?
My code is something like this :
Connection con = .....
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(blablabla...);
if (rs.next() = ...)
ResultSet rs = stmt.executeQuery(blablabla);
}

Answer 1

If I want to to a select statement and depending on
the result a second select, can I do this on the same
statement object, or do I have to create a new one?You can reuse your first statement and execute another query with it. But this would close your first resultset. If you want to use two resultsets at the same time, they must be created by different statements.
Note that not all combinations of DBMS / driver support different active statements in 1 connection. In that case you would use a second connection for the second statement.
And what about the resultset? Can you re-use this?You created a simple statement. So you can only position in it downwards by next() and retrieve values. If you execute another query by the same statement, your statement will close the first resultset and return a new one.
And do you always close this statement after using it, or
can you just close it when the program finishes?If you close it, you must create a new one if you need it again.
No problem to let it remain open.
At the end of your program then close them all in the right order:
1. resultset (if still remained unclosed)
2. statement (if still remained unclosed)
3. connection (if still remained unclosed)