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From david myers <david.myers.scibearsp...@gmail.com>
Subject Re: Derby Key Words
Date Mon, 26 Nov 2012 22:16:15 GMT
Hello All,

As always first off I should appologise for being quiet, i've been 
reading through the code and I think I start to understand things that 
were not very clear to me previously.

My current situation is now the following

I've got myself well sorted out.

Eclipse now has a 'handle' on the svn repo (copied locally of course), 
and I've been able to grab Dag's patch and it to this, all from inside 
eclipse (which I'm pleased worked out).

Dag's code is interesting, very cool.

I feel my next steps are as follows...

I need to write a new class (or extend an existing one). I guess 
something in DB MetaData. But what and where?
Then I need to test it. Where should I put my test class (or again 
should I add the test to a class that already exists.

I feel that I am now ready to implement this. I just need some pointers 
of how to run my individual test case (I make the assumption that as I'm 
not going near anything else in the first instance I shouldn't break it 
(that is also why I propose a new subclass of one of the existing 
dbMetaData classes).

I hope to become a little more active before christmass

David.


On 15/10/12 20:48, david myers wrote:
> Dag,
>
> thanks for the info. I'll have a try with that later on.
> One thing though, should I not be in my < derby trunk sandbox of 
> checked out from svn[1] > before doing wget (surely I'll end up with 
> it in the wrong place)... I'm probably showing my ignorance about wget 
> and svn as I've not done this sort of stuff before ;)
>
> Not that it matters, I'll check it out later on....
>
> David
>
> On 15/10/12 13:06, Dag Wanvik wrote:
>> Hi David,
>>
>> to access the patch I made, you need to download the patch attached to
>> the JIRA issue, e.g. this way
>>
>> $ wget --no-check-certificate
>> https://issues.apache.org/jira/secure/attachment/12544418/derbykeywords-1.diff 
>>
>> $ cd <your Derby trunk sandbox of checked out from svn[1]>
>> $ patch -p0 < derbykeywords-1.diff
>>
>> Hope this works!
>>
>> [1] See here
>> http://db.apache.org/derby/dev/derby_source.html#Development+trunk
>> $ svn checkout https://svn.apache.org/repos/asf/db/derby/code/trunk/
>>
>> Since my patch only did part of what you wanted, I didn't commit it yet,
>> so feel free to build on it.
>> Good luck!
>>
>> Thanks,
>> Dag
>>
>> On 14.10.2012 20:28, david myers wrote:
>>> Hi all,
>>>
>>> must apologise for being so quiet,busy with my 'real' job etc. However
>>> this doesn't mean I've been ignoring what I want to do.
>>>
>>> I've been reading around the code to determine the files that I am
>>> going to require to initiate this little modification. I think I am
>>> begining to understand how things work a little better. Firstly
>>> however I want to ensure I have well understood.
>>>
>>> The file sqlgrammar.jj is read by javacc and creates a bunch of other
>>> .java clases.
>>>
>>> SQLParserConstants.java is one of these files, it is an interface that
>>> is implemented by the SQLParser class (also created from 
>>> sqlgrammar.jj).
>>>
>>> So if I can modify sqlgrammar.jj I could 'inject' into the SQLParser
>>> class a method that return the list of static final members (stored in
>>> the tokenImage string array member, so in fact I could just return
>>> this member).
>>>
>>> My problems currently now revolve around the following.
>>>
>>> DAG has created a method that reads the sqlgrammar.jj file directly
>>> and creates the Keywords.java file. I can't seem to find this in my
>>> source tree, is this related to needing the specific DERBY-3256
>>> checkout. I've tried using the SVN plugin for eclipse to find this
>>> checkout, but so far to no success. Any chance someone could walk me
>>> through doing this from the CLI (ubuntu 12.04).
>>>
>>> Should I mention at this point I'm rather new to SVN (actually version
>>> control in general!), did I say previously this is my first multi
>>> person project?
>>> sorry I digress....
>>>
>>> I've located the files that I think I'm going to need.
>>> EmbededDataBaseMetaData[40].java and TestDBMetaData.java where I will
>>> put my < getDerbyKeyWords() > method and test.
>>>
>>> Rik thanks for waving your hands about the compile time tool. I think
>>> this may be what I need to implement my < getTokenImage() > so any
>>> pointers would be great.
>>>
>>> Once I've got the method working locally I guess I'll need to create a
>>> bug or something, that points to the various JIRA issues, and then
>>> solve it.... but for me that comes a little later. For now I want to
>>> write the method into my local tree only. Then recompile, test ...
>>> blah blah blah...
>>>
>>> Is this an acceptable way in which to proceed? Any suggestions advice
>>> are welcome.
>>>
>>> Thanks in advance.
>>>
>>> David.
>>>
>>>
>>>
>>>
>>> On 10/09/12 01:23, Dag Wanvik wrote:
>>>> Hi,
>>>>
>>>> I added an experimental patch to DERBY-3256 which seems to do (part
>>>> of) the job. It uses the actual lists from sqlgrammar.jj to generate
>>>> Keywords.java at compile time, and wraps those in a table function.
>>>> There is no metadata function in it but it could be used to provide
>>>> those functions, I think, if we decide that's the way to go.
>>>>
>>>> Dag
>>>>
>>>> On 05.09.2012 23:28, david myers wrote:
>>>>> On 05/09/12 06:25, Katherine Marsden wrote:
>>>>>> On 9/4/2012 7:44 PM, Bryan Pendleton wrote:
>>>>>>>> I've had success in pointing Eclipse to the source code that
I
>>>>>>>> have built. I have had a nice look around for the file that
I am
>>>>>>>> interested in, which from the previously mentioned JIRA issues
>>>>>>>> etc suggest a file called sqlgrammar.jj
>>>>>>>> only problem is I can't find it!
>>>>>>> It's possible that Eclipse doesn't grok '.jj' files in its normal
>>>>>>> configuration.
>>>>>>>
>>>>>>> The file should be in your source tree as:
>>>>>>>
>>>>>>> ./java/engine/org/apache/derby/impl/sql/compile/sqlgrammar.jj
>>>>>>>
>>>>>>> There is a compiler-generation tool that processes this file
during
>>>>>>> the Ant build of Derby and generates Java source from the grammar.
>>>>>>>
>>>>>>   The tool that generates the java code for the parser from
>>>>>> sqlgrammar.jj is  Javacc.  The generated code is in
>>>>>> generated/java/org/apache/derby/impl/sql/compile which is fun to
>>>>>> look at but shouldn't be changed.
>>>>>> I think there may be an exclipse plugin for javacc but I have never
>>>>>> used one.
>>>>>>
>>>>>> Kathey
>>>>>>
>>>>>>
>>>>> Hello again all,
>>>>>
>>>>> Sorry I hate to pollute the thread, but I want to ensure that I do
>>>>> things 'the apache way' and not just my way!
>>>>> So I need a little advice.
>>>>> First some info.
>>>>>
>>>>> The file as mentioned by Bryan has been located. Thanks to Kathey's
>>>>> pointer I have found the actual java file that is going to be of
>>>>> interest to me.
>>>>>
>>>>> The files that I think are going to be informative are:
>>>>> SQLParserConstants.java ~ this is the interface
>>>>> SQLParser ~ a class file that implements this interface is
>>>>> This file is found in Source Folder: generated/java/
>>>>>                                         package:
>>>>> org.apache.derby.impl.sql.compile
>>>>>
>>>>> So now it is a question of testing out my idea !
>>>>> The interface <SQLParserConstants.java> has no methods, only static
>>>>> final "int" members.
>>>>>
>>>>> This leads me to a potential solution as follows:
>>>>>
>>>>> Create a method that has an inner class that implements the
>>>>> SQLParserConstants.java interface
>>>>> This inner class has a single method that grabs all of the members
>>>>> and inserts them into a arrayList<String> - for "equal time access"
>>>>> to the values.
>>>>>
>>>>> We can then access this arrayList and compare a passed in value to
>>>>> determine if the value exists in the list.
>>>>>
>>>>> My first idea is to test the method within a test class, a good
>>>>> candidate for its location is the following I think.
>>>>>
>>>>> TestDbMetaData
>>>>> located in source folder java/test
>>>>> package ~ org.apache.derbyTesting.functionTests.tests.jdbc4
>>>>>
>>>>> Or alternatively I can create a separate test class to test the idea
>>>>> (which would probably be my preference to start with, then once it
>>>>> works as I would like it to everything can be copied into a more
>>>>> sensible location.
>>>>>
>>>>> Once I have the method functioning I could add it into a specific
>>>>> package (probably databaseMetaData), then test it in situ.
>>>>>
>>>>> Does the above seem like a valid process?
>>>>>
>>>>> I have a few queries about the test suite.
>>>>> I have been using Junit4 from within eclipse, and I'm aware that you
>>>>> use Junit 3.8. I notice that with your test files you don't use
>>>>> annotations for the methods. With the exception of the setup and
>>>>> tear down methods, how do you control the flow through the test? In
>>>>> Junit 4 you place a <@Test> token on the line before the method
if
>>>>> you want the method to run, along with annotations like <@before>
if
>>>>> there are any that need to come before other stuff.
>>>>> Also my test classes have only really had 1 method I want to run at
>>>>> a time, so I just comment out the <@Test> annotation to effectively
>>>>> turn off the method.
>>>>>
>>>>> Please add your comments.
>>>>>
>>>>> David
>


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