Detecting if a record has changed

[Ryan How]

Hi, I notice internally that JOOQ stores whether there have been changes to a record. Is there a way to access this. I want to use it to detect if a record is dirty and needs committing. I can't find any public methods that expose the functionality. eg record.hasChanges(), or record.isDirty()

Additionally it would be great to have the original values accessible also, but I can just fetch again from the database, so that's not a biggy :). Would also mean a lot more memory overhead I guess if you are updating a large recordset.

Thanks! Ryan

[Lukas Eder]

Hello,

> Hi, I notice internally that JOOQ stores whether there have been changes to
> a record. Is there a way to access this. I want to use it to detect if a
> record is dirty and needs committing. I can't find any public methods that
> expose the functionality. eg record.hasChanges(), or record.isDirty()

So far, I tried to avoid exposing these internals. But there's no
general reason why this shouldn't be exposed (I think). I'll evaluate
this as feature request #1848:
https://github.com/jOOQ/jOOQ/issues/1848

In the mean time, note that you can just store() any record. If there
are no changes, no SQL statement will be executed, and the result
should be 0:

record.setValue(VALUE, "changed value");
assertEquals(1, record.store());
assertEquals(0, record.store());

> Additionally it would be great to have the original values accessible also,
> but I can just fetch again from the database, so that's not a biggy :).
> Would also mean a lot more memory overhead I guess if you are updating a
> large recordset.

Original values are referenced in UpdatableRecords already, as can be seen here:
https://github.com/jOOQ/jOOQ/blob/master/jOOQ/src/main/java/org/jooq/impl/Value.java

This was necessary to implement the optimistic locking feature. I'll
consider exposing them as well.

Cheers
Lukas

[Ryan How]

Thanks,

I wanted to use it to detect if the record is dirty, so then it can
prompt the user to save or not before actually saving.
I'll use a bit of reflection and hope the internals don't change to much :)

Thanks, Ryan

[Lukas Eder]

> I wanted to use it to detect if the record is dirty, so then it can prompt
> the user to save or not before actually saving.

OK, I'll see what I can do. It shouldn't be hard to add.

> I'll use a bit of reflection and hope the internals don't change to much :)

Chances are, that the next version will have this feature implemented.
So don't worry about changing internals.
Or, you could hook an ExecuteListener into the Factory, detecting if a
store() *would* execute an UPDATE or not, and then abort the UPDATE
;-)

Cheers
Lukas

[Lukas Eder]

I have implemented #1849:
https://github.com/jOOQ/jOOQ/issues/1849

// This has been added to Record
Record original()

// ... and it is overridden for increased type-safety in TableRecord<R
extends Record> as
R original()

I'll see what can be done about the isChanged flags in a bit...

[Lukas Eder]

#1848 is implemented, too
https://github.com/jOOQ/jOOQ/issues/1848

// This has been added to Record

boolean changed()

If you want to discover the concrete changed value(s), you can compare
Record with Record.original()

Cheers
Lukas

[Ryan How]

Wow, you are efficient!

Thanks!

I couldn't pay for support that good :)

[Lukas Eder]

> I couldn't pay for support that good :)

Yes you can! Here:
http://sourceforge.net/project/project_donations.php?group_id=283484

;-)

[Ryan How]

;)

[Lukas Eder]

Thank you very much, Ryan. I really appreciate your donation!

Am Montag, 1. Oktober 2012 schrieb Ryan How <rh...@exemail.com.au>:
> ;)
>
>