Hi,

please note above varchar length will be given as default. eg:-
varchar(250).

Regards,
damith.

On Mon, Dec 1, 2014 at 5:10 PM, Damith Wickramasinghe <[email protected]>
wrote:

> Hi,
>
> Thanks Anjana and Lahiru for the suggestions. Please find below the found
> observations.
>
>
> Following are the DB actions.
>
> - DB creation (IF NOT EXIST)
> - Table creation (IF NOT EXIST)
> - Insert data to table
> - update data to table
>
> Since all the DBMS's are using same DDL and DML query formats we can keep
> the query formats static for all DB types. Also we are only considering
> above db actions only
>
> eg:-
>
> CREATE TABLE table_name
> (
>   column1 datatype [ NULL | NOT NULL ],
>   column2 datatype [ NULL | NOT NULL ],
>   ...
> );
>
> UPDATE table
> SET column1 = expression1,
>     column2 = expression2,
>     ...
> WHERE conditions;
>
>
> INSERT INTO table
> (column1, column2, ... )
> VALUES
> (expression1, expression2, ... ),
> (expression1, expression2, ... ),
> ...;
>
>
> issue for the above implementation is the query syntax differs(Some) from
> DB type to another (eg.data types) . So decided to use a XML file which has
> DB type specific data types. So dynamically we can access the db type and
> retrieve data types to generate the query in prepared statement.
>
> Xml file would be like following.
>
> <mappings>
> <mapping db='ansi'>
>     <types>
>               <type>
>                        <from>string</from>
>                        <to>VARCHAR</to>
>               </type>
>               <type>
>                        <from>double</from>
>                        <to>DOUBLE</to>
>               </type>
>
>     </types>
> </mapping>
> <mapping db='mysql'>
>     <types>
>         //mysqi specific data types if any
>
>     </types>
> </mapping>
> <mapping db='oracle'>
>     <types>
>         <type>
>               <from>string</from>
>               <to>varchar2</to>
>          </type>
>     </types>
> </mapping>
> <mapping db='mssql'>
>     <types>
>         <type>
>               <from>string</from>
>               <to>varchar2</to>
>          </type>
>     </types>
> </mapping>
> <mapping db='h2'>
>     <types>
>         //h2 specific data types if any
>     </types>
> </mapping>
> </mappings>
>
> Like wise above xml can be created.  Main idea is to use a separate XML to
> manipulate different data types.  According to above XML first checks for
> specific data type in specific db mappings. If not found then the value is
> read from the generic data type mapping as stated as <mapping db='ansi'>.
> All the data type mappings are not included in above configuration.
>
> Your suggestions & feedbacks are highly appreciated.
>
>
>
>
>
>
> On Sat, Nov 29, 2014 at 11:15 AM, Lahiru Cooray <[email protected]> wrote:
>
>> Hi,
>> Maintenance wise it's nice to keep queries in separate XML.
>> And I think it's better to keep all the generic queries in a one section
>> of the XML and keep DBMS specific queries in separate sections. So you
>> don't need to rewrite common queries for each type. Also better to consider
>> MS SQL Server as well in testing  ( if it's supported DB type) as there are
>> many syntax differences compared to Oracle and mysql
>>
>> On Fri, Nov 28, 2014 at 4:49 PM, Damith Wickramasinghe <[email protected]>
>> wrote:
>>
>>> Hi,
>>>
>>> Currently we have the support only for Mysql and it is decided to
>>> implement a generic adapter to support any RDBMS database. For now adapter
>>> implementation will be focused on supporting Oracle, Mysql and H2.
>>>
>>> I will update the thread on decided architecture for the said
>>> requirement soon. Any feedbacks on the requirement will be greatly
>>> appreciated.
>>>
>>> Regards,
>>> Damith.
>>>
>>> --
>>> Software Engineer
>>> WSO2 Inc.; http://wso2.com
>>> <http://www.google.com/url?q=http%3A%2F%2Fwso2.com&sa=D&sntz=1&usg=AFQjCNEZvyc0uMD1HhBaEGCBxs6e9fBObg>
>>> lean.enterprise.middleware
>>>
>>> mobile: *+94728671315 <%2B94728671315>*
>>>
>>>
>>> _______________________________________________
>>> Architecture mailing list
>>> [email protected]
>>> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
>>>
>>>
>>
>>
>> --
>> *Lahiru Cooray*
>> Software Engineer
>> WSO2, Inc.;http://wso2.com/
>> lean.enterprise.middleware
>>
>> Mobile: +94 715 654154
>>
>> _______________________________________________
>> Architecture mailing list
>> [email protected]
>> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
>>
>>
>
>
> --
> Software Engineer
> WSO2 Inc.; http://wso2.com
> <http://www.google.com/url?q=http%3A%2F%2Fwso2.com&sa=D&sntz=1&usg=AFQjCNEZvyc0uMD1HhBaEGCBxs6e9fBObg>
> lean.enterprise.middleware
>
> mobile: *+94728671315 <%2B94728671315>*
>
>


-- 
Software Engineer
WSO2 Inc.; http://wso2.com
<http://www.google.com/url?q=http%3A%2F%2Fwso2.com&sa=D&sntz=1&usg=AFQjCNEZvyc0uMD1HhBaEGCBxs6e9fBObg>
lean.enterprise.middleware

mobile: *+94728671315*
_______________________________________________
Architecture mailing list
[email protected]
https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture

Reply via email to