Hi Angelo,
There is something you and I are both missing.
1) There should be nothing magic about GenericRecord versus CustomObject. All
of my EOModels have CustomObjects for the reasons you noted (you want to add
helper methods, etc.). They also have both derived attributes but more often
regular attributes that use read / write format. I’ve never received the error
you encountered.
2) Maybe you are using a special MySQLPlugin that has some issue. I tried
searching for bits and pieces of the error message that was generated for you
but I can’t find it in my code base.
3) It looks like your ReadFormat test was on the cusp of working. An
“IllegalStateException” is a java error meaning it never got to the point of
talking to the Database before throwing up its hands. A “JDBCAdaptorException”
means that the java knew what you were asking so went ahead to query the DB but
then had a problem. Double check that you had the correct prototype (varchar)
for the attribute in your EOModel. Double check that the raw SQL would work.
Turn on “EOAdaptor Debug” so you can see the generated SQL and verify by hand
that it makes sense.
log4j.logger.er.transaction.adaptor.EOAdaptorDebugEnabled=DEBUG
Sorry you’re having trouble with this.
AARON ROSENZWEIG / Chat 'n Bike
e: aa...@chatnbike.com t: (301) 956-2319
On Mar 23, 2014, at 11:58 AM, Ângelo Andrade Cirino <aacir...@gmail.com> wrote:
> Hi Aaron,
>
> Thank you for your prompt answer. Unfortunately none of the suggestions
> worked.
>
> 1) I can't find any combination of double or single apostrophe that will
> work. A similar MySQL SELECT statement is as simple as this
>
> select Party.id as partyID, (case status
> when 0 then 'Active'
> when 1 then 'Inactive'
> end) as fullStatus from Party;
>
> Even this simple derived attribute that returns a constant won't work (from
> the plist entity file):
>
> {
> columnName = fullStatus;
> definition = "'Full Status'";
> name = fullStatus;
> prototypeName = varchar16;
> },
>
> with the following error:
>
> IllegalStateException: sqlStringForAttribute: attempt to generate SQL for
> attribute 'fullStatus' on entity 'Party' with undefined column name. You must
> define a column name for this attribute before attempting a database
> operation.
>
> 2) The read format option didn't work either since the attribute is an
> integer number and the return value is a string. I attempted this format:
>
> if(%P,'Active','Inactive')
>
> and it resulted in this error:
>
> JDBCAdaptorException: Invalid value for getInt() - 'Inactive'
>
> However, this works just fine as a read format:
>
> if(%P,2*%P,5*%P)
>
> But I am stubborn and think that a derived attribute is a desirable
> attribute. I would like to use it for more complex operations, for example
> involving concatenation of strings in related entities.
>
> Anyway, trying to figure out what is happening, it occurred to me that my
> Party entity is a custom class, so I tried a non-custom class with a simple
> entity to see if the derived attribute would work. And it worked. My simple
> tentative entity is this:
>
> {
> attributes = (
> {columnName = code; name = code; prototypeName = intNumber; },
> {
> columnName = fullStatus;
> definition = "case code when 0 then 'Active' when 1 then
> 'Inactive' end";
> isReadOnly = Y;
> name = fullStatus;
> prototypeName = varchar16;
> userInfo = {"_EntityModeler" = {generateSource = NO; }; };
> },
> {allowsNull = N; name = id; prototypeName = id; }
> );
> attributesUsedForLocking = (code, id);
> className = "er.extensions.eof.ERXGenericRecord";
> classProperties = (code, fullStatus);
> externalName = Status;
> fetchSpecificationDictionary = {};
> name = Status;
> primaryKeyAttributes = (id);
> }
>
> But this isn't a solution for me, since my entity will have a lot of business
> logic that demands a custom class. Perhaps I should set my Party entity as a
> ERXGenericRecord and then subclass it to implement the business logic.
>
> The question is, why does EO expect a column for a derived attribute for a
> custom class and not for a ERXGenericRecord?
>
> By the way, the original Apple EOModeler User Guide doesn't state that a
> derived attribute will not work for a custom class nor does the documentation
> states that a derived attribute should be modeled for a generic record.
>
> Angelo
>
> 2014-03-23 1:01 GMT-03:00 Aaron Rosenzweig <aa...@chatnbike.com>:
> Hi Angelo,
>
> Couple things to try:
>
> 1) Remove the single apostrophes surrounding “status” and try again. It is
> possible that it isn’t parsing properly… don’t column names need to have
> “double apostrophes” ??? Perhaps MySQL is lax about that but still… Either
> use no apostrophe or use a “double apostrophe” meaning a single character the
> shift-apostrophe key. If it is a single apostrophe that is a String in SQL.
>
> 2) Try a different way. Remove all the code you have in the derived part and
> make this a normal EOAttribute. Put “STATUS” in there by itself. Now go to
> the “advanced” tab and type what you want in the “Read Format” and check the
> “read only” box. In the read format you want to use %P for your columnName so
> you’ll want something like this:
>
> case %P when 0 then 'Active' when 1 then 'Inactive’ end
>
> Honestly, I almost always use the #2 way and never the “derived” way because
> it is more flexible. I like the idea that I define the column in one box and
> in another I write something complex but refer to it with %P.
>
> Try it out and report back.
> AARON ROSENZWEIG / Chat 'n Bike
> e: aa...@chatnbike.com t: (301) 956-2319
>
>
>
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