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Thread: Ask about autocommit etc.

  1. #1
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    Default Ask about autocommit etc.

    Hello everybody, i am new in Java Programming language.. I have a confussion when i try to develop database on my application.. Oke, this is my confussion.

    public boolean updateBook(Book b){
            String query = "UPDATE BOOK SET "
            + "id=?, categori=?, title=?, date=?, source=?, number=?, "
            + "year=?, count=?"
            + "WHERE id=?";
            PreparedStatement statement=null;
            try {
                statement = connection.prepareStatement(query);
                for(int i=1;i<=8;i++)
                    statement.setObject(i, b.getObject(i));
                statement.setInt(9, b.getId());
                connection.setAutoCommit(false);
                if(statement.executeUpdate()==1)
                    connection.commit();
            } catch (SQLException ex) {
                JOptionPane.showMessageDialog(null, "Error when update data\n Error: "+ex.getMessage());
                try { connection.rollback(); } catch (SQLException exr) {}
                return false;
            }finally{try {if(statement != null)statement.close(); } catch (Exception e) { }}
            return true;
        }

    I want to know:
    1. Why the "connection.setAutoCommit()" is used?
    2. When should i set the "connection.setAutoCommit(false)" to "false" or set to "true"?
    3. Why the "connection.commit();" is used?
    4. Why in the try and catch, are used the "connection.rollback();" ? What is the meaning of this?

    I hope at least one of you can give me explanation about my trouble above.
    Please help me to solve it.. Thank you very much. GBU All..
    Last edited by Yoga Herawan; October 5th, 2011 at 07:27 PM.


  2. #2
    Super Moderator copeg's Avatar
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    Default Re: Ask about autocommit etc.


  3. The Following User Says Thank You to copeg For This Useful Post:

    Yoga Herawan (October 6th, 2011)

  4. #3
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    Default Re: Ask about autocommit etc.

    Quote Originally Posted by copeg View Post
    Thank you very much Mr copeg, i will read this.. If i still confuse, i hope You want to help me..