Mysql, transactions and connections

Hi,
I have two problems:
1. I am using mysql 3.23 and JBuilder 6 and I would like to use transactions.
I created a database and a table InnoDb and when I try from my application to setautocommit(false) I get the following error:
See com.borland.dx.dataset.DataSetException error code: BASE+66
com.borland.dx.dataset.DataSetException: Cannot disable AUTO_COMMIT
I tried lots of things in the mysql server and in my application and I don't know wether it's a configuration of the server, something I need to set first in the WinMySqlAdmin or something I have to do in my application.
I would really use some help.. If anyone could also provide a small example please..
2. It's also related to Mysql
I have a server that opens a connection to the database. I want to know what I have to set in the mysql server so that the connection is not lost if the server is not active a long time.. I thought that if I set the interactive_timeout and the wait_timeout at a high level the problems would be solved but when I did some testing by setting the values to 30 seconds the connection persisted. Does anyone know why?
Please help
Thanks

"MySql does not support transactions" is correct.
Basically there are no commit or rollback statements
available in MySql. This is I am talking about
version 3.2.3 I believe. I have used it long back.incorrect.
if you use the default myISAM tables than there is no transaction support. however, if you use INNODB then there is transaction support available in versions of 3 etc. for sure.
however, you need a driver that knows this and supports this. i believe the newer versions of the mysql driver support them i know the older org.gjt.mm driver does NOT.
what driver are you using? some borland one? look at the support there.

Similar Messages

Distributed transactions and connection pooling

Hi,
We have a problem with the enlistment of connections in distributed transactions.
The following very simple C# program does not work correctly (a simple form with one button and a class hosted in COM+). If you put a breakpoint on "cnOraTx.Close();" you will see that the inserted record is already visible in the database although the transaction has not commited yet.
If you comment out the lines between //START and //END everything works as expected.
Also, if we use "Pooling=false" in the connection string, everything works fine again, but since we are writing a web application, we really need the connection pooling.
We are using ODP.NET 9.2.0.2.102 (I also tried with the ODP.NET 9.2.0.4.0 BETA) and an oracle 8.1.7 database.
Best Regards,
Piet
private void button1_Click(object sender, System.EventArgs e)
//When commenting the following lines the connection is enlisted in the distributed transaction
//START
OracleConnection cnOraTx;
cnOraTx = new Oracle.DataAccess.Client.OracleConnection("Data Source=ECOMP532;User ID=USER;Password=PWD");
cnOraTx.Open();
cnOraTx.Close();
cnOraTx.Dispose();
//END
OpenOraTransConn obj = new OpenOraTransConn();
obj.Connect();
//This class is going to be hosted within COM+
[Transaction(TransactionOption.Required)]
public class OpenOraTransConn: ServicedComponent
private OracleConnection cnOraTx;
private OracleCommand cmd;
internal void Connect()
cnOraTx = new OracleConnection("Data Source=ECOMP532;User ID=USER;Password=PWD");
cnOraTx.Open();
cmd = new OracleCommand();
cmd.Connection = cnOraTx;
cmd.CommandText = "INSERT INTO SYSADM.PERSON (PE_KEY) VALUES(130000)";
cmd.ExecuteNonQuery();
cnOraTx.Close();
cnOraTx.Dispose();
ContextUtil.SetComplete();

Hello:
We are experiencing the exact same problem. INSERT, UPDATE or DELETE statements that should roll back because an exception is being thrown from inside our ServicedComponent-derived class (which is set to TransactionOption.Required and uses AutoComplete) are not -- and instead are being committed to the database.
Were you able to figure out why this is happening, and what can be done to get around it? We too were able to avoid the problem by setting Pooling=False to our connect string, but for a variety of reasons we want to use connection pooling ...!

Problem with transacted JMS connection factory and transaction timeouts

          We encountered an interesting problem using transacted JMS connection factories.
          An EJB starts a container managed transaction and tries to validate a credit card
          before creating some information to a database for the user, in case of success
          an SMS is sent to the user via the transacted JMS queue. If the credit card authentications
          duration is about the same as the transactions timeout (in this case the default
          30 seconds) sometimes the database inserts is committed but the JMS insert is
          rollbacked. How can this be?
          If the authorization duration is much longer than 30 seconds everything works
          fine (both database and JMS inserts rollbacked), the same is true if a rollback
          is insured by calling EJBContext.setRollbackOnly(). The problem thus occurs only
          if the duration is approximately the same as the transaction timeout, it appears
          that the database insert is not timeouted but the JMS insert is. How can this
          be if they are both participating in the same transaction.
          The JMSConnectionFactory used is a Connection factory with XA-enabled. The result
          is the same also with the default "javax.jms.QueueConnectionFactory" and if we
          configure our own factory with user transactions enabled.
          Any help appreciated!


Tomas Granö wrote:
          > We encountered an interesting problem using transacted JMS connection factories.
          > An EJB starts a container managed transaction and tries to validate a credit card
          > before creating some information to a database for the user, in case of success
          > an SMS is sent to the user via the transacted JMS queue. If the credit card authentications
          > duration is about the same as the transactions timeout (in this case the default
          > 30 seconds) sometimes the database inserts is committed but the JMS insert is
          > rollbacked. How can this be?
          It should not be.
          >
          > If the authorization duration is much longer than 30 seconds everything works
          > fine (both database and JMS inserts rollbacked), the same is true if a rollback
          > is insured by calling EJBContext.setRollbackOnly(). The problem thus occurs only
          > if the duration is approximately the same as the transaction timeout, it appears
          > that the database insert is not timeouted but the JMS insert is. How can this
          > be if they are both participating in the same transaction.
          >
          > The JMSConnectionFactory used is a Connection factory with XA-enabled. The result
          > is the same also with the default "javax.jms.QueueConnectionFactory" and if we
          > configure our own factory with user transactions enabled.
          >
          > Any help appreciated!
          Make sure that your session is not "transacted". In other words,
          the first parameter to createSession() must be false. There is an
          unfortunate name re-use here. If a session is "transacted", it
          maintains an independent "inner transaction" independent of the
          outer transaction. From the above description, it seems unlikely
          that your application has this wrong, as you say that
          "setRollbackOnly" works - but please check anyway.
          Make sure that you are using a true XA capable driver and database
          (XA "emulation" may not suffice)
          Beyond the above, I do not see what can be going wrong. You
          may want to try posting to the transactions and jdbc newsgroups. Note
          that JMS is appears to be exhibiting the correct behavior, but the
          JDBC operation is not. The JDBC operation appears to have
          its timeout independent of the transaction monitor's timeout.
          Tom

MySQL - Transactions without locks?

Hi , I am using the native transaction support of mysql innodb ( setautocommit(false) etc etc).
I also want to have multiple connections to the database which are able to update the same rows etc. - -now the error I'm getting is 'lock wait timeout'.
Probably this forum is not the exact place for this question, but is there any way of unlocking the rows? ie i start a transaction, insert some row, then want another connection/transaction to be able to update that row - and then commit or rollback either transaction I feel like. Timeout is not a solution as i want overlapping transactions.
This might sound mad/bad but please don't reply telling me its dangerous etc etc
Any help much appreciated,
thanks

Hi , I am using the native transaction support of
mysql innodb ( setautocommit(false) etc etc).
I also want to have multiple connections to the
database which are able to update the same rows etc.
- -now the error I'm getting is 'lock wait timeout'.
Probably this forum is not the exact place for this
question, but is there any way of unlocking the rows?
ie i start a transaction, insert some row, then want
another connection/transaction to be able to update
that row - and then commit or rollback either
transaction I feel like. Timeout is not a solution
n as i want overlapping transactions.
As far as I know, no database does overlapping transactions. (I suspect that either it is not feasible or it would have a huge performance impact. Or both.)
So your choice is either to live with the locks or stop using explicit transactions and write one row at a time.

Connection pool and Connection factory difference?

Hi,
Can someone clarify the difference between connection pool and connection factory.
I know connection pool is some thing like a pool of database connection manitained at one place so that an application or client can use it when it requires.
Then wat exactly is connection factory..say in 10g we always put a connection factory name in all adapters and acces the data sources like DB ,FTP,AQ ..etc
can someone clarify??
regards,

To conserve system resources and to improve the performance of transactional applications, WebLogic allows you to define a pool of client connections (generally database but may be a FTP,FILE etc. as well)
A Connection Factory object encapsulates a set of connection configuration parameters that has been defined by an administrator. A client uses it to create a connection with a service provider (generally JMS).
Regards,
Anuj

Re: Transactions and Locking Rows for Update

Dale,
Sounds like you either need an "optimistic locking" scheme, usually
implemented with timestamps at the database level, or a concurrency manager.
A concurrency manager registers objects that may be of interest to multiple
users in a central location. It takes care of notifying interested parties
(i.e., clients,) of changes made to those objects, using a "notifier" pattern.
The optimistic locking scheme is relatively easy to implement at the
database level, but introduces several problems. One problem is that the
first person to save their changes "wins" - every one else has to discard
their changes. Also, you now have business policy effectively embedded in
the database.
The concurrency manager is much more flexible, and keeps the policy where
it probably belongs. However, it is more complex, and there are some
implications to performance when you get to the multiple-thousand-user
range because of its event-based nature.
Another pattern of lock management that has been implemented is a
"key-based" lock manager that does not use events, and may be more
effective at managing this type of concurrency for large numbers of users.
There are too many details to go into here, but I may be able to give you
more ideas in a separate note, if you want.
Don
At 04:48 PM 6/5/97 PDT, Dale "V." Georg wrote:
I have a problem in the application I am currently working on, which it
seems to me should be easily solvable via appropriate use of transactions
and database locking, but I'm having trouble figuring out exactly how to
do it. The database we are using is Oracle 7.2.
The scenario is as follows: We have a window where the user picks an
object from a dropdown list. Some of the object's attributes are then
displayed in that window, and the user then has the option of editing
those attributes, and at some point hitting the equivalent of a 'save'button
to write the changes back to the database. So far, so good. Now
introduce a second user. If user #1 and user #2 both happen to pull up
the same object and start making changes to it, user #1 could write back
to the database and then 15 seconds later user #2 could write back to the
database, completely overlaying user #1's changes without ever knowing
they had happened. This is not good, particularly for our application
where editing the object causes it to progress from one state to the next,
and multiple users trying to edit it at the same time spells disaster.
The first thing that came to mind was to do a select with intent to update,
i.e. 'select * from table where key = 'somevalue' with update'. This way
the next user to try to select from the table using the same key would not
be able to get it. This would prevent multiple users from being able to
pull the same object up on their screens at the same time. Unfortunately,
I can think of a number of problems with this approach.
For one thing, the lock is only held for the duration of the transaction, so
I would have to open a Forte transaction, do the select with intent to
update, let the user modify the object, then when they saved it back again
end the transaction. Since a window is driven by the event loop I can't
think of any way to start a transaction, let the user interact with the
window, then end the transaction, short of closing and re-opening the
window. This would imply having a separate window specifically for
updating the object, and then wrapping the whole of that window's event
loop in a transaction. This would be a different interface than we wanted
to present to the users, but it might still work if not for the next issue.
The second problem is that we are using a pooled DBSession approach
to connecting to the database. There is a single Oracle login account
which none of the users know the password to, and thus the users
simply share DBSession resources. If one user starts a transaction
and does a select with intent to update on one DBSession, then another
user starts a transaction and tries to do the same thing on the same
DBSession, then the second user will get an error out of Oracle because
there's already an open transaction on that DBSession.
At this point, I am still tossing ideas around in my head, but after
speaking with our Oracle/Forte admin here, we came to the conclusion
that somebody must have had to address these issues before, so I
thought I'd toss it out and see what came back.
Thanks in advance for any ideas!
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, Inc. [email protected]
>
>
>
>
====================================
Don Nelson
Senior Consultant
Forte Software, Inc.
Denver, CO
Corporate voice mail: 510-986-3810
aka: [email protected]
====================================
"I think nighttime is dark so you can imagine your fears with less
distraction." - Calvin

We have taken an optimistic data locking approach. Retrieved values are
stored as initial values; changes are stored seperately. During update, key
value(s) or the entire retieved set is used in a where criteria to validate
that the data set is still in the initial state. This allows good decoupling
of the data access layer. However, optimistic locking allows multiple users
to access the same data set at the same time, but then only one can save
changes, the rest would get an error message that the data had changed. We
haven't had any need to use a pessimistic lock.
Pessimistic locking usually involves some form of open session or DBMS level
lock, which we haven't implemented for performance reasons. If we do find the
need for a pessimistic lock, we will probably use cached data sets that are
checked first, and returned as read-only if already in the cache.
-DFR
Dale V. Georg <[email protected]> on 06/05/97 03:25:02 PM
To: Forte User Group <[email protected]> @ INTERNET
cc: Richards* Debbie <[email protected]> @ INTERNET, Gardner*
Steve <[email protected]> @ INTERNET
Subject: Transactions and Locking Rows for Update
I have a problem in the application I am currently working on, which it
seems to me should be easily solvable via appropriate use of transactions
and database locking, but I'm having trouble figuring out exactly how to
do it. The database we are using is Oracle 7.2.
The scenario is as follows: We have a window where the user picks an
object from a dropdown list. Some of the object's attributes are then
displayed in that window, and the user then has the option of editing
those attributes, and at some point hitting the equivalent of a 'save' button
to write the changes back to the database. So far, so good. Now
introduce a second user. If user #1 and user #2 both happen to pull up
the same object and start making changes to it, user #1 could write back
to the database and then 15 seconds later user #2 could write back to the
database, completely overlaying user #1's changes without ever knowing
they had happened. This is not good, particularly for our application
where editing the object causes it to progress from one state to the next,
and multiple users trying to edit it at the same time spells disaster.
The first thing that came to mind was to do a select with intent to update,
i.e. 'select * from table where key = 'somevalue' with update'. This way
the next user to try to select from the table using the same key would not
be able to get it. This would prevent multiple users from being able to
pull the same object up on their screens at the same time. Unfortunately,
I can think of a number of problems with this approach.
For one thing, the lock is only held for the duration of the transaction, so
I would have to open a Forte transaction, do the select with intent to
update, let the user modify the object, then when they saved it back again
end the transaction. Since a window is driven by the event loop I can't
think of any way to start a transaction, let the user interact with the
window, then end the transaction, short of closing and re-opening the
window. This would imply having a separate window specifically for
updating the object, and then wrapping the whole of that window's event
loop in a transaction. This would be a different interface than we wanted
to present to the users, but it might still work if not for the next issue.
The second problem is that we are using a pooled DBSession approach
to connecting to the database. There is a single Oracle login account
which none of the users know the password to, and thus the users
simply share DBSession resources. If one user starts a transaction
and does a select with intent to update on one DBSession, then another
user starts a transaction and tries to do the same thing on the same
DBSession, then the second user will get an error out of Oracle because
there's already an open transaction on that DBSession.
At this point, I am still tossing ideas around in my head, but after
speaking with our Oracle/Forte admin here, we came to the conclusion
that somebody must have had to address these issues before, so I
thought I'd toss it out and see what came back.
Thanks in advance for
any
ideas!
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, Inc. [email protected]
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To: Forte User Group <[email protected]>
Cc: "Richards," Debbie <[email protected]>,
"Gardner," Steve <[email protected]>
MIME-Version: 1.0
From: Dale "V." Georg <[email protected]>
Subject: Transactions and Locking Rows for Update
Date: Thu, 05 Jun 97 16:48:37 PDT
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Reply-To: Dale "V." Georg <[email protected]>

Transactions and Locking Rows for Update

I have a problem in the application I am currently working on, which it
seems to me should be easily solvable via appropriate use of transactions
and database locking, but I'm having trouble figuring out exactly how to
do it. The database we are using is Oracle 7.2.
The scenario is as follows: We have a window where the user picks an
object from a dropdown list. Some of the object's attributes are then
displayed in that window, and the user then has the option of editing
those attributes, and at some point hitting the equivalent of a 'save' button
to write the changes back to the database. So far, so good. Now
introduce a second user. If user #1 and user #2 both happen to pull up
the same object and start making changes to it, user #1 could write back
to the database and then 15 seconds later user #2 could write back to the
database, completely overlaying user #1's changes without ever knowing
they had happened. This is not good, particularly for our application
where editing the object causes it to progress from one state to the next,
and multiple users trying to edit it at the same time spells disaster.
The first thing that came to mind was to do a select with intent to update,
i.e. 'select * from table where key = 'somevalue' with update'. This way
the next user to try to select from the table using the same key would not
be able to get it. This would prevent multiple users from being able to
pull the same object up on their screens at the same time. Unfortunately,
I can think of a number of problems with this approach.
For one thing, the lock is only held for the duration of the transaction, so
I would have to open a Forte transaction, do the select with intent to
update, let the user modify the object, then when they saved it back again
end the transaction. Since a window is driven by the event loop I can't
think of any way to start a transaction, let the user interact with the
window, then end the transaction, short of closing and re-opening the
window. This would imply having a separate window specifically for
updating the object, and then wrapping the whole of that window's event
loop in a transaction. This would be a different interface than we wanted
to present to the users, but it might still work if not for the next issue.
The second problem is that we are using a pooled DBSession approach
to connecting to the database. There is a single Oracle login account
which none of the users know the password to, and thus the users
simply share DBSession resources. If one user starts a transaction
and does a select with intent to update on one DBSession, then another
user starts a transaction and tries to do the same thing on the same
DBSession, then the second user will get an error out of Oracle because
there's already an open transaction on that DBSession.
At this point, I am still tossing ideas around in my head, but after
speaking with our Oracle/Forte admin here, we came to the conclusion
that somebody must have had to address these issues before, so I
thought I'd toss it out and see what came back.
Thanks in advance for any ideas!
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, Inc. [email protected]
[email protected]------------------

I have a problem in the application I am currently working on, which it
seems to me should be easily solvable via appropriate use of transactions
and database locking, but I'm having trouble figuring out exactly how to
do it. The database we are using is Oracle 7.2.
The scenario is as follows: We have a window where the user picks an
object from a dropdown list. Some of the object's attributes are then
displayed in that window, and the user then has the option of editing
those attributes, and at some point hitting the equivalent of a 'save' button
to write the changes back to the database. So far, so good. Now
introduce a second user. If user #1 and user #2 both happen to pull up
the same object and start making changes to it, user #1 could write back
to the database and then 15 seconds later user #2 could write back to the
database, completely overlaying user #1's changes without ever knowing
they had happened. This is not good, particularly for our application
where editing the object causes it to progress from one state to the next,
and multiple users trying to edit it at the same time spells disaster.
The first thing that came to mind was to do a select with intent to update,
i.e. 'select * from table where key = 'somevalue' with update'. This way
the next user to try to select from the table using the same key would not
be able to get it. This would prevent multiple users from being able to
pull the same object up on their screens at the same time. Unfortunately,
I can think of a number of problems with this approach.
For one thing, the lock is only held for the duration of the transaction, so
I would have to open a Forte transaction, do the select with intent to
update, let the user modify the object, then when they saved it back again
end the transaction. Since a window is driven by the event loop I can't
think of any way to start a transaction, let the user interact with the
window, then end the transaction, short of closing and re-opening the
window. This would imply having a separate window specifically for
updating the object, and then wrapping the whole of that window's event
loop in a transaction. This would be a different interface than we wanted
to present to the users, but it might still work if not for the next issue.
The second problem is that we are using a pooled DBSession approach
to connecting to the database. There is a single Oracle login account
which none of the users know the password to, and thus the users
simply share DBSession resources. If one user starts a transaction
and does a select with intent to update on one DBSession, then another
user starts a transaction and tries to do the same thing on the same
DBSession, then the second user will get an error out of Oracle because
there's already an open transaction on that DBSession.
At this point, I am still tossing ideas around in my head, but after
speaking with our Oracle/Forte admin here, we came to the conclusion
that somebody must have had to address these issues before, so I
thought I'd toss it out and see what came back.
Thanks in advance for any ideas!
Dale V. Georg
Indus Consultancy Services [email protected]
Mack Trucks, Inc. [email protected]
[email protected]------------------

How can I include a MySQL table and records with the PUT of my Dreamweaver site?

I am using .php to validate a user code against one of four codes that I am providing to potential clients. They enter that code, along with a default user id and the appropriate page is then displayed for them. Everything is working fine on the desktop. I need to have this table and the records created on my remote server. I tried saving the table in the Connections folder, but that didn't help. Everytime I enter a code (valid or invalid) on the live site, I get the following message: "Table 'boundsauctions_com.promocode' doesn't exist". Is there someway to include the table and records in my Dreamweaver folders for the site?
Thanks for any help that you can offer.

You can't. Dreamweaver, or FTP for that matter has no connection to the MySQL database. If you have created a MySQL database locally and now wish to move/copy it to your server you'll need to create a back up of your local database and then log into your database on the server and then restore that back up.
An even easier way to do this, and if you are working with MySQL much at all a good investement is to get the commercial version of Navicat MySQL - this is the best MySQL administrator I've found to date and is well worth the few bucks to buy it. With Navicat you can connect to your local MySQL database and also create a connection to your remote database, then literally drag and drop your local database contents to copy them to your server. This function alone justifies buying Navicat. A huge time saver. And no I do not work for or have any share or ties to Navicat. I'd recommend something else if I knew of anything better, but so far I don't.
Hope this helps. If you need any more details let me know.
Lawrence Cramer - *Adobe Community Professional*
http://www.Cartweaver.com
Shopping Cart for Adobe Dreamweaver
available in PHP, ColdFusion
Stay updated - http://blog.cartweaver.com

Problem with use of COM+ Transaction and DB Transaction

Problem with use of COM+ Transaction and DB Transaction
We build a Web site that use sometime COM+ Transaction and sometime DB
Transaction. If we use a COM+ Transaction and a few seconds later we try to use
a Database Transaction (OracleConnection.BeginTransaction), we get the error
Connection is already part of a local or a distributed transaction
Of course the error does not produce everytime; it takes some try before we get
the problem. And of course, if i use pooling=false on the connection string,
the problem does not appear.
i run the Web page
and push the COM+ Transaction and DB Transaction one after the other for some
times and the problem should appear.
Environment: Windows server 2003, .Net Framework 1.1, ODP.Net 9.2.0.401,
Database Server 9.2.0.4

> Why in form builder can't I...
Is this happening at runtime or at buildtime? You'll need to provide more info on what you are actually doing that's causing the problem.
Regards,
Robin Zimmermann
Forms Product Management

Bean Managed Transactions and rollback

Hi Everybody,
I am using Bean Managed Transactions in a Message Bean which is called every some time by an EJB3 timer. This Message Bean subsequently calls a Session Bean which uses Container Managed Transactions and uses the default transaction attribute which is SUPPORTS. The Session Bean methods might sometime throw a System Exception(inheriting from RuntimeException) which will rollback the Bean Managed Transaction which was started from the Message Bean.
When this happens and I try to invoke userTransaction.rollback() I get invalid transaction state exception and I suppose this means that is already rolled back.
Is there a way to get another transaction or set the transaction back to a valid state so I can carry on with some persistence tasks or the only way to do that is by suppressing the RuntimeException and throwing an Application Exception having the *@ApplicationException(rollback=false)* annotation? Can I suppress a System Exception though?
Thank you in advance!

Saroj wrote:
Hi All,
I would like to know whether we can use JDBC Connection Object's commit and rollback
methods to control Transaction in Bean Managed Transactions or not.You may use the JDBC connection's transaction support from an EJB. That being said, you
need to understand that it won't be the transaction that started declaratively by the
EJB container nor would it be a bean-managed transaction started through
UserTransaction.
FWIW, I question why you'd want to do this though. I'd use container-managed
transactions and let the container handle this for you. The transaction manager
includes a 1PC optimization so it's not going to do an XA/2PC tx if you only have a
single resource in the tx. Also, the EJB container includes all the logic to properly
handle rollbacks when exceptions are thrown etc.
Finally, your code will more maintainable and reusable if you use the container-managed
tx + JTA resources. If I later wanted to call another EJB or another JTA resource (eg
JMS perhaps) I could do it without having to rewrite all of your code.
-- Rob
>
>
Why is it required that we should use Java Transaction API to control the Transaction
in Our Beans?
I understand that if we are using Multiple Resources and need to use Transaction
then going for JTA makes sense. If I am using only Resource,for example, Only One
Connection then we should be able to use Connection's Transaction control.
I understand that other way to do the transaction is to use Container's transaction
services.
Please respond at the earliest.
Thanks in Advance,
Saroj

Confused, which MySQL database to connect to: local (WAMP), or remote?

Hello, new to dynamic sites, have successfully installed WAMP and set up my local/testing/remote sites in DW CS4. Most tutorials I've found recommend making the "MySQL Connection" in Dreamweaver to the local (WAMP) installation of MySQL, which I am able to do. But my remote site already has an existing MySQL database and tables. So should I be making the MySQL Connection to the remote database instead? Or exporting the remote server's database and importing it locally for development purposes? What's the best practice?
If making the connection to my local database is recommended, how do I transfer any changes that I make on my local db to the remote database? Do I need to export locally & import to the remote db, using phpmyadmin, every time I make changes to the local database?
If making the connection to my remote database is recommended, I have 2 questions: 1) do I even need my local WAMP MySQL database for anything? and 2) I was able to connect to my remote MySQL, (first got "MySQL ERROR 1045 Access Denied", but then went into my remote server via CPanel, found the "Remote MySQL" function, and entered my long current domain name as a new Access Host), but since I'm at a home office without a static IP, will I have to keep going into CPanel and entering in a new Access Host every time my IP address changes?
Apologies for the confusion. Any pointers to recommended best practices would be much appreciated.
- Frank

> 2) I was able to connect to my remote MySQL, (first got "MySQL ERROR 1045
> Access Denied", but then went into my remote server via CPanel, found the
> "Remote MySQL" function, and entered my long current domain name as a new
> Access Host), but since I'm at a home office without a static IP,
> will I have to keep going into CPanel and entering in a new Access Host every time
> my IP address changes?
Update: my IP address changed slightly yesterday and I was denied remote MySQL access again. Went back to CPanel and modified my Access Host domain with a few wildcard characters (blah-blah-blah-%%%%.dsl.bell.ca). That got me back in. Is this what most people who want remote MySQL access do? Is it a (significant) security risk?
Or do most people without static IPs just not bother with remote MySQL access?

Distributed Transactions and Linked Servers

I'm somewhat of a novice with SQL Server but I'm learning rapidly from an application I'm developing that uses SQL Server very heavily. In conjunction with the development of this application, I have 3-4 systems set up running SQL Server and I am using those
systems to develop the database that will ultimately support the application. I decided to try to use linked servers because I am moving data back-and-forth among the different servers frequently and I ran into some consequences that I wasn't expecting.
I was doing a simple delete query on one of the servers (Delete from TableName Where ...) and I was expecting, of course, that it would only impact the server I was running it on; however, when the query finished after running for a long time, it was apparent
that SQL Server had automatically escalated that simple delete query into a distributed transaction and applied it to all four of the linked servers I had defined. I was totally surprised by that and it took some time to recover the data that was inadvertently
lost on the other servers.
I want to ensure that this doesn't happen again without me expecting it - I think the right way to prevent this from happening is to run the following stored procedure:
EXEC sp_serveroption 'servername', 'remote proc transaction promotion', 'false';
Can someone please verify that this assumption is correct and will prevent SQL Server from automatically creating distributed transactions impacting multiple servers?
Thanks,
Chuck

Hello,
Based on your description, it seems that when you connect to a SQL Server database and execute a DELETE statement to delete a recode on a table, and then the same recode were delete in the linked server which has the same table.
As pre my understand, the statement executed on one server will not apply to the linked servers unless you specify the logic yourself in the application. For example, you use dynamic query and exec the query synchronously on linked servers.
What's more, did you specify replication between this linked server?
If I have any misunderstanding, please let me know.
Regards,
Fanny Liu
If you have any feedback on our support, please click here.
Fanny Liu
TechNet Community Support

MySql database and php code on different servers

I created a table on a MySql database on server A. Now I'm
trying to create
a page to display the contents of the table. I know that the
html code ( and
php) is on a different server (server B). I managed to create
a database
connection however when I try this connection I cannot see
the table I
created. When I click on the Connection name I get the Stored
Procedures,
Tables and View list. I click on the Tables and although I
get a connection
to the server A, no table is displayed.
Am I trying to do something silly here?
any help will be appreciated.
Twanny

> Am I trying to do something silly here?
I do it this way all the time. My testing server is local to
my development
LAN, but the MySQL server and database is remote (on the
remote site). To
make this work, you would have to make sure that the remote
server permits
an external connection. If it does, you should be golden.
Murray --- ICQ 71997575
Adobe Community Expert
(If you *MUST* email me, don't LAUGH when you do so!)
==================
http://www.projectseven.com/go
- DW FAQs, Tutorials & Resources
http://www.dwfaq.com - DW FAQs,
Tutorials & Resources
==================
"Twanny" <[email protected]> wrote in message
news:gabbu1$ngv$[email protected]..
>I created a table on a MySql database on server A. Now
I'm trying to create
>a page to display the contents of the table. I know that
the html code (
>and php) is on a different server (server B). I managed
to create a
>database connection however when I try this connection I
cannot see the
>table I created. When I click on the Connection name I
get the Stored
>Procedures, Tables and View list. I click on the Tables
and although I get
>a connection to the server A, no table is displayed.
>
> Am I trying to do something silly here?
>
> any help will be appreciated.
>
>
>
>
> --
> Twanny
>

Managed datasources, Global transactions and XA

I have a question regarding the use of managed datasources and global transactions with oc4j 10.1.3.
From the documentation at:
http://download-west.oracle.com/docs/cd/B25221_04/web.1013/b14428/servdats.htm#CHDGJECC
I conclude that managed datasources by default support global transactions.
I have tested the following scenario:
A stateless session bean starts a container managed transaction. The bean updates data in two different databases through two different
managed datasources. The transaction is atomic.
What surprises me is that this works. I would think that I would need to configure the datasources to make use of XA.
Can someone explain why this works, wat is the difference between XA transactions and global transactions in this context?

Further to give more info the error users are facing is
Could not connect to 'oracle.jdbc.xa.client.OracleXADataSource'.

How to conncet mysql database and oracle database 11g2 on linux 5.4

Hi,
Can anyone help me to connect mysql server database to Oracle
database on Linux OS?
I have done all things, but I am getting a problem in installing dg4odbc
driver on Oracle database. In a simple word, I don't know how to create
listener between mysql database and Oracle database.
If anyone knows that please help me in configuring dg4odbc for Oracle. OS
-Linux 5.4 and refer any doc or link.
oracle 11g2 11.2.0.1
i follow the metalink id - 466228.1 ( but cant successed).
Thanks and regards,
pritesh ranjan

hi pl z clear me it is required to install manully the dg4odbc driver for oracle to connect MySQL server database. because in my $ORACLE_HOME/hs/admin/initdg4odbc.ora is present automatically.
details of the initdg4odbc.ora
# This is a sample agent init file that contains the HS parameters that are
# needed for the Database Gateway for ODBC
# HS init parameters
HS_FDS_CONNECT_INFO = mysql_odbc
HS_FDS_TRACE_LEVEL = off
HS_FDS_SHAREABLE_NAME = /usr/lib/libmyodbc5w.so
# ODBC specific environment variables
set ODBCINI=/etc/odbc.ini
set LD_LIBRARY_PATH=/usr/lib
# Environment variables required for the non-Oracle system
#set HOME=/home/oracle
~
~
~
"initdg4odbc.ora" 20L, 437C
details of the listener.ora file
DG4ODBC =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA=(SID=dg4odbc))
(HS=OK)
SID_LIST_ORCL =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = orcl)
(ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1)
(SID_NAME = ORCL)
ADR_BASE_DG4ODBC = /u01/app/oracle
ORCL =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = pritesh11gprim.oracle.com)(PORT = 1521))
ADR_BASE_ORCL = /u01/app/oracle
"listener.ora" [readonly] 37L, 779C 35,0-1 85%
details of tnsname.ora file
# tnsnames.ora Network Configuration File: /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
ORCL =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.132)(PORT = 1521))
(CONNECT_DATA =
(SERVICE_NAME = ORCL)
DG4ODBC =
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521))
(CONNECT_DATA=(SID=DG4ODBC))
(HS=OK)
MYSQL =
(DESCRIPTION=
(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521))
(CONNECT_DATA=(SID=MYSQL))
(HS=OK)
when i m going to start the listener it could not be started..
details of the mysql server database
[root@pritesh11gprim ~]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.6.10 MySQL Community Server (GPL)
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
mysql> show databases;
| Database |
| information_schema |
| demo |
| mysql |
| performance_schema |
| pritesh |
| test |
6 rows in set (0.01 sec)
if any where i m wrong then plz suggest me......
thanks & regards
pritesh ranjan

Mysql, transactions and connections

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