Enthuware

For this question,

"Assuming that the table student2 does not have any row, how many rows will be present in this table after the following code is executed? "


"Assuming that the table student2 does not have any row"

does this statement have any relevance on the choice to select?

Well, if the table already has rows, then none of the options can be valid.

So, 'setAutoCommit(true)' saves all previously pending 'inserts'? (this sounds strange...)

leorbarbosa wrote:So, 'setAutoCommit(true)' saves all previously pending 'inserts'? (this sounds strange...)

Yes, but only if the auto commit mode was false before. You should go through this JavaDoc description: http://docs.oracle.com/javase/7/docs/ap ... t(boolean)

I am having some issues with MySQL otherwise I would try this myself but here is my question....

Does calling conn.rollback() (w/o a savepoint passed in) roll all statements in the transaction back or does it rollback statements up until it encounters and unnamed savepoint?

pseudocode:
autocommit(off)
stmt.executeupdate(1)
savepoint unnamed
stmt.executeupdate(2)
savepoint named
rollback - no savepoint given
commit

Does this sequence rollback back to the unnamed savepoint and then commit update1 or does it rollback everything and commit nothing?

A call to rollback() will roll back all the changes done in this transaction (irrespective of any save points).
A call to rollback(SavePoint) will roll back only those changes made after the given save point.
So in your example everything (after setting autocommit(off) ) will be rolled back.
HTH,
Paul.

I agree with rollback and savepoint logic for 2 rows.

But database will not be updated unless:
Statement stmt = c.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);

NOT Statement stmt = c.createStatement();