- Does closing statement close connection?
- Can we commit inside a trigger?
- What happens if you don’t commit a transaction?
- How do you commit a transaction in Java?
- Can we rollback to savepoint after commit?
- What is the difference between commit and savepoint?
- Do you need to close ResultSet?
- Which statement is used to turn off auto commit mode of a connection?
- What is the difference between commit and rollback?
- What is the correct order to close database resources?
- Can we rollback after commit?
- Can we rollback after commit in MySQL?
- Does delete need commit?
- Which is better truncate or delete?
- Do I need to close PreparedStatement?
Does closing statement close connection?
Closing Connection will close any Statement s that connection has created.
Closing any Statement will close all ResultSet s that were created by that Statement .
Doesn’t matter if Connection is poolable or not.
Even poolable connection has to clean before returning to the pool..
Can we commit inside a trigger?
Trigger should not commit and cannot commit. Committing in a trigger usually raises an exception unless it happens into autonomous transaction. When you open connection, Oracle creates session for it.
What happens if you don’t commit a transaction?
As long as you don’t COMMIT or ROLLBACK a transaction, it’s still “running” and potentially holding locks. If your client (application or user) closes the connection to the database before committing, any still running transactions will be rolled back and terminated.
How do you commit a transaction in Java?
Commit/Rollback transaction exampleLoad the JDBC driver, using the forName(String className) API method of the Class. … Create a Connection to the database. … Disable auto commit, with the setAutoCommit(boolean autoCommit) API method of the Connection. … Do SQL updates and commit each one of them, with the commit() API method of the Connection.More items…•
Can we rollback to savepoint after commit?
You can only roll back to the most recently marked savepoint. An implicit savepoint is marked before executing an INSERT , UPDATE , or DELETE statement. If the statement fails, a rollback to the implicit savepoint is done.
What is the difference between commit and savepoint?
COMMIT − to save the changes. ROLLBACK − to roll back the changes. SAVEPOINT − creates points within the groups of transactions in which to ROLLBACK.
Do you need to close ResultSet?
You should close ResultSet and Statement explicitly because Oracle has problems previously with keeping the cursors open even after closing the connection. If you don’t close the ResultSet (cursor) it will throw an error like Maximum open cursors exceeded.
Which statement is used to turn off auto commit mode of a connection?
You can turn off/on the auto-commit using the setAutoCommit() method of the Connection interface.
What is the difference between commit and rollback?
COMMIT permanently saves the changes made by current transaction. ROLLBACK undo the changes made by current transaction. Transaction can not undo changes after COMMIT execution. Transaction reaches its previous state after ROLLBACK.
What is the correct order to close database resources?
If you want to explicitly close them in a row then you need to close them in the reverse order of creation: ResultSet, Statement, Connection. Also you need to wrap each close into try/catch, since they throw an exception as far as I remember.
Can we rollback after commit?
A transaction is a sequence of SQL statements that Oracle Database treats as a single unit. … After you commit the transaction, the changes are visible to other users’ statements that execute after the commit. You can roll back (undo) any changes made during the transaction with the ROLLBACK statement (see ROLLBACK.
Can we rollback after commit in MySQL?
No, there’s no query that will “undo” a committed data-modifying query. If you have a backup of the database, you can restore the backup and use DBA tools (in MySQL’s case, it’s mysqlbinlog) to “replay” all data-modifying queries from the logs since the backup back to the database, but skip over the problem query.
Does delete need commit?
And a key point – although TRUNCATE TABLE seems like a DELETE with no WHERE clause, TRUNCATE is not DML, it is DDL. DELETE requires a COMMIT, but TRUNCATE does not.
Which is better truncate or delete?
Truncate reseeds identity values, whereas delete doesn’t. Truncate removes all records and doesn’t fire triggers. Truncate is faster compared to delete as it makes less use of the transaction log.
Do I need to close PreparedStatement?
Even though every Statement and PreparedStatement is specified to be implicitly closed when the Connection object is closed, you can’t be guaranteed when (or if) this happens, especially if it’s used with connection pooling. You should explicitly close your Statement and PreparedStatement objects to be sure.