Robert,
That is how I had originally understood the configuration parameters to work. Thanks.
BTW, Michael sent a reply that I interpreted his meaning to be that the CM configuration could conflict with itself. Your explanation seems to be consistent with how I would expect it to work.
Unless I am off track with Michael's response, I feel I understand yours a bit better.
Thanks,
Joe
On Apr 20, 2010, at 4:24 PM, Robert Zeigler wrote:
> Cayenne generates the appropriat AUTO_PK_SUPPORT table regardless of the pk
> generation strategy, but if your pk generation strategy is "Database
> Generated" (AND if your db + driver support auto-pk generation), it won't
> actually use it; it will allow the database to generate the id and use the
> generated id.
>
> Robert
>
> On Tue, Apr 20, 2010 at 9:15 AM, Joe Baldwin <jfbaldwi..arthlink.net>wrote:
>
>> Michael,
>>
>> I need a simple verification (because the webhost tech person is very
>> confused).
>>
>> To explain further: I am using Cayenne Modeler to design the entities, and
>> to create the database tables in MySQL. (i.e. Tools - Generate Database
>> Schema). My understanding, and my tests have proved, if you set [PK
>> Generation Strategy] to "Database-Generated", and [Auto Incremented] to "oid
>> (INTEGER)" then Cayenne Modeler will "request/instruct/ask " MySQL to create
>> a table, then set the oid as the primary key, and set auto_increment to
>> "true" for that field.
>>
>> The following code was generated by the Cayenne Modeler (I deleted
>> everything not having to do with the table or key)
>>
>> CREATE TABLE pickers.product (PRIMARY KEY (oid)) ENGINE=InnoDB;
>> CREATE TABLE AUTO_PK_SUPPORT ( TABLE_NAME CHAR(100) NOT NULL,
>> NEXT_ID BIGINT NOT NULL, UNIQUE (TABLE_NAME));
>> DELETE FROM AUTO_PK_SUPPORT WHERE TABLE_NAME IN ('product');
>> INSERT INTO AUTO_PK_SUPPORT (TABLE_NAME, NEXT_ID) VALUES ('product',
>> 200);
>>
>>
>> The question now is: Has Cayenne Modeler generated SQL that creates a table
>> named "product", with a primary key "oid", whose value is automatically
>> created by MySQL's InnoDB engine, using auto_increment, at the time of the
>> INSERT? Another way of asking this is: In this scenario, does Cayenne
>> generate the key, or does MySQL generate the key?
>>
>> I would like to forward a brief response to the webhost.
>>
>> Thanks,
>> Joe
>>
>>
>>
>>
>> On Apr 20, 2010, at 9:25 AM, Michael Gentry wrote:
>>
>>> Hi Joe,
>>>
>>> Your wording on #2 and #3 was a little curious to me. I don't know if
>>> you used Cayenne Modeler to generate your schema or if you are using
>>> an existing schema. Cayenne (at runtime) doesn't really instruct the
>>> database (MySQL) to auto-generate keys. Cayenne will nont provide a
>>> value for "oid" when inserting the record and that essentially
>>> instructs MySQL to auto-generate a key. You set this up when you
>>> create your product table, for example. The database needs to know
>>> that it is responsible for auto-generating the keys -- Cayenne won't
>>> tell it at runtime (other than leaving the key out on insert).
>>>
>>> Maybe I'm a bit off on what you were asking, but it seems like you are
>>> expecting Cayenne to tell MySQL to generate the keys when it actually
>>> works the other way around: MySQL is supposed to know to generate the
>>> key and Cayenne then asks it for the key it generated.
>>>
>>> mrg
>>>
>>> PS. BTW, your settings are correct to use the auto-generated key
>>> feature in MySQL, just be sure the table was created to auto-generate
>>> on your "oid" column.
>>>
>>>
>>> On Mon, Apr 19, 2010 at 8:03 PM, Joe Baldwin <jfbaldwi..arthlink.net>
>> wrote:
>>>> I apologize for this, but I am being forced to verify a configuration
>> that is pretty obvious.
>>>>
>>>> Please refer to the attached CM configuration panel for an Entity.
>>>>
>>>> 1. The Primary Key "PK Generation Strategy" is set to
>> "Database-Generated". Please verify that this means that the PK Generation
>> Strategy is Database Generated.
>>>> 2. The Primary Key "Auto Increment" is set to "oid (INTEGER)". Please
>> verify that the field being auto-incremented is "oid".
>>>> 3. Please verify that (with the DBMS set to MySQL) that the two previous
>> parameters instruct MySQL to use its auto_increment feature to create a new
>> "oid" value for inserted records.
>>>>
>>>> Thanks
>>>> Joe
>>>>
>>>>
>>>>
>>
>>
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