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From Prashanth Sukumaran <prashanthsukuma...@yahoo.com>
Subject Re: Vendor specific queries?
Date Wed, 07 Sep 2005 01:32:51 GMT
I understand that.  Coz., with iBatis even now we use multiple files for different databases.
 I thought you were suggesting something different.  
 
Sorry about that.


Scott Zhu <scottzhu@gmail.com> wrote:
No, the way the localization look up work in java, you have one default property file, and
the ones with locale postfix. For example, you have staticMessages.properties and staticMesage_en_GB.properties.
In the latter one, you only store the british english specific tranlations. At runtime, if
the locale is set to en_GB, it will always look up in staticMessages_en_GB.properties first,
then staticMessages_en.properties (if it's there), then  staticMessages.properties. By the
same approach, we can have bar.xml for all generic queries, then bar_ORACLE.xml, bar_DB2.xml.
We can use either the file name or name space concept.

 
On 9/6/05, Prashanth Sukumaran <prashanthsukumaran@yahoo.com> wrote: I don't know if
this would be a good idea.  Consider your example of Localization resource lookup(not the
directory based approach but the file based approach) for example the ApplicaitonResouces.properties
in struts, are you saying it is good to have one huge file with sections like INI file for
different language_Country.  
 
This does not make sense at all.
 
Considering the suggestion, then it would end up with all kinds of different queries for different
for databases in one large file. I wouldn't do it.  I don't know if others would.
 
Prashanth Sukumaran.

Scott Zhu <scottzhu@gmail.com> wrote: 
Yes, we used some approach like this, but we have to do it on our own. I'd like to see this
to be done in iBatis. Essecially, this could work like localization resource lookup in java,
if the database type is oracle, it first looks in that name space (or something), if it can't
find the statement there, it then falls back to the default name space one. So we only need
to define vendor specific statement in its own xml file. Just my 2cents. 

On 9/6/05, Ron Grabowski <rongrabowski@yahoo.com > wrote: You could create different
property files per each vendor that contain
database specific things (like the select key statement, GETDATE() , 
etc.) and use it this way:

<selectKey keyProperty="ID" resultClass="long">
${SELECT_KEY}
</selectKey>

Some people use this property syntax to group database specific sql 
maps:

<sqlMap resource="/SqlMaps/${VENDOR}/Foo.xml"/>
<sqlMap resource="/SqlMaps/${VENDOR}/Bar.xml"/>
<sqlMap resource="/SqlMaps/${VENDOR}/Baz.xml"/>

A colleague of mine suggested an alternative approach that hasn't been
implemented yet. His idea is to add a namespace attribute to the
statement node and allow that to override a particular statement node.
For example if there are 30 statement nodes in Foo, Bar, and Baz and 
you need to override just one or two statement f or Oracle you would be
able to include the differing statements in their own small file:

<update id="Update" namespace="Foo"> 
...
</update>
<select id="GetMany" namespace="Bar">
...
</select>

The resource nodes would look something like this:

<sqlMap resource="/SqlMaps/Foo.xml"/> 
<sqlMap resource="/SqlMaps/Bar.xml"/>
<sqlMap resource="/SqlMaps/Baz.xml"/>
<sqlMap resource="/SqlMaps/${VENDOR}.xml"/>

Yes, that would require you to always have a Oracle.xml, MSSQL.xml,
etc. Maybe a "ignoreMissingSqlMapResource" setting is in order too ???

--- Patrick Lightbody < patrick@jivesoftware.com> wrote: 

> Hey guys - great work on iBatis. I finally spent some time on it and
> I
> must say I prefer this method of storage much more than other options
> out there. In fact, the next version of WebWork (whi ch I am a 
> developer
> for) will contain integration with iBatis. Now, on to my question:
>
> I've seen in the docs where vendor-specific features, especially 
> around
> sequence handling, are done like so: 
>
> <select name="insertFoo-ORACLE" .../>
> <select name="insertFoo-MYSQL" .../>
>
> What I can't tell is if this is just some naming convention, or if 
> something trickier is going on here. Can iBatis run certain 
> "versions"
> of a statement based on the database vendor it is currently connected
> to? If not, maybe this would be a good feature to add? In fact, any 
> place a query could be written, if there could be an optional 
> "vendor"
> attribute that could be used, that would be great. The end result
> would
> be:
>
> <select name="insertFoo" ...> 
>         <selectKey keyProperty="ID" resultClass="long" 
> vendor="postgres">
>             SELECT nextval('category_seq') as ID
>         </selectKey>
>         <selectKey keyProperty="ID" resultClass="long"
> vendor="oracle">
>             SELECT nextval('category_seq') FROM dual as ID
>         </selectKey> 
>         INSERT ...
>         <selectKey keyProperty="ID" resultClass="long" 
> vendor="mssql">
>             SELECT @@IDENTITY...
>         </selectKey> 
> </select>
>
> _________________
> Patrick Lightbody
> Professional Services 
> Jive Software
> patrick@jivesoftware.com
> www.jivesoftware.com
> 317 SW Alder, Ste 500
> Portland, OR 97204 
> ph (503) 295-6552
> fx (503) 961-1047




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