Re: Using BLOBs with several DBMS

From: Ricardo Maia <rmaia(at)criticalsoftware(dot)com>
To: Stephen Crawley <crawley(at)dstc(dot)edu(dot)au>, Ricardo Maia <rjmaia(at)student(dot)dei(dot)uc(dot)pt>
Cc: pgsql-interfaces(at)postgresql(dot)org, crawley(at)dstc(dot)edu(dot)au
Subject: Re: Using BLOBs with several DBMS
Date: 2001-06-08 11:48:25
Message-ID: 0106081248250F.00816@valkyrie
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Thanks Stephen.

Maybe I'll follow your second sugestion ...

Do you kown any JDBC Drivers (even if comercial) for PostgreSQL and/or Oracle
that implements fully the Blobs API?

Ricardo Maia

On Friday 08 June 2001 06:30, Stephen Crawley wrote:
> > My question is: how can i create a table with one BLOB field, in a DBMS
> > independent way?
> >
> > I am using PostgreSQL7.1 and Oracle 8 but I want to make it be able to
> > work with other DBMSs.
>
> It is difficult, because:
>
> * Different versions of SQL use different names for the BLOB type.
>
> * Some DBMS don't support blobs at all.
>
> * Some DBMS treat blobs differently to other SQL types and
> require you to use special APIs to access them.
>
> * Not all JDBC drivers support the JDBC 2.0 Blob APIs. Of those
> that do, many implement them in part only.
>
> Given this mess, you've got two choices:
>
> * Define a Java interface for all of your database interactions.
> Create a different implementation for each DBMS you plan to support,
> complete with embedded SQL statements, table schemas, etc.
>
> * Define wrapper classes for JDBC, and try to isolate the DBMS
> differences in "adapters". This (more or less) allows you to
> share SQL statements / table schemas across DBMS, but it is
> kind of hard getting the wrapper / adapter APIs right.
>
> -- Steve
>
>
>
>
>
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