Varun Arya:
i have custom table having primary key with autoincrement. As of now i know there are these ways to insert records to table.
Well, no, you know of the one right way to do it (using createXxx(0)) and two incorrect ways of doing it (using CounterLocalServiceUtil, doubly wrong because your instance will have a counterLocalService reference that you're not using and you're violating the rule of using the LocalServiceUtil classes inside of the service layer).
When you use autoincrement, you're deferring to Liferay to assign the primary key. When you pass in the special value 0, Liferay uses this as a flag that the new value should be assigned.
In first if i want to get promary key value i gets 0, second long value, third incremented value wrt table name. I am using thid one. Now if i re-deploy the service or portlet counter value will be incresed 101,201,... And this can be handled by setting counter.increment.xxx.Class=1 or counter.increment=1.
That is an artifact of the counter local service handling. The normal "block" of next sequence numbers are retrieved in 100s. So the first deployment the block starting from 101 through 200 is retrieved and cached. As new records are entered, they will get the next value from the block so you will find records assigned as 101, 102, 103, ...
On the next deployment (or app server restart), the counter local service doesn't know which ids from the previous block were used, so it starts with a new block, 201 through 300, to assign from there. Each new redeploy or restart will result in a new block.
But i just want to get database table incremented value from "xxx". So there is any way to do this. Like this:
XXX xxx = new XXXImpl();
xxx.setValue(value);
XXXLocalServiceUtil.addXXX(xxx);
Here i can get the value which i want from database table.
First you should never, ever be doing new XXXImpl() directly. You never know if Liferay might change the underlying code to create a new instance and your code would all of a sudden break with no clear reason why.
Just stick with the "Xxx xxx = createXXX(0);" form.
Now it sounds like you're actually asking about the ID type "sequence" which defers to a database assigned key value. Start by checking the Liferay service builder DTD file to get the details on the sequence assignment and what databases are supported by sequences.
You still use the "createXXX(0)" form to create a new instance, but your problem is that you are not using the value returned by the addXXX() call.
When you do "xxx = addXXX(xxx);", xxx will be reassigned the value from the add call where the sequence value would be assigned and returned.
Also with the continuing use of XxxLocalServiceUtil, it looks like you are doing this kind of thing outside of the service layer.
The purpose of your service layer is to encapsulate (hide) service implementation details. Like this one for example. Outside code shouldn't care whether you need to use a zero, assign by a counter or are relying on a sequence value to assign the ids. Outside code just needs to insert a new record given a list of parameters.
That's why you'll see that Liferay code commonly has some sort of addXxx() method in the XxxLocalServiceImpl class that takes a list of parameters as arguments. Inside the body of the addXxx() method, that is where the createXxx(0) followed by the setter calls and finishing with a "return addXxx(xxx);" to complete the addition of the new object.
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Devcon 2017 or
2017 LSNA!
Thank you so much.