Re: [Druid-devel] A better JDBC import

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Wed Nov 26 2003 - 03:24:29 EST

  • Next message: antonio-petrelli..ibero\.it: "Re: [Druid-devel] A better JDBC import"

    Umm... How is this related to Cayenne and this particular list?

    Andrus

    On Nov 26, 2003, at 2:55 AM, antonio-petrell..libero..it wrote:

    >> The DatabaseIOModule is intended to import into druid / export from
    >> druid
    >> database schemas in various formats. It not indended to be used via
    >> jdbc.
    >>
    >> I have given a look at cayenne sources and the conclusion is:
    >> the reverse engineering capability of cayenne is *not* better than
    >> druid's one.
    >>
    >> You say that cayenne uses adapters to interface with different dbms.
    >> If you
    >> look at the code, you'll find that the adapters are almost empty and,
    >> almost
    >> all, contain code to create a table and a sequence. Only the oracle
    >> adapter
    >> seems to be a little better giving the possibility to write blobs and
    >> clobs.
    >>
    >> Hence, I see that cayenne uses only a standard jdbc api for reverse
    >> engineering.
    >> Because you say that druid fails, I see only 2 possible causes:
    >>
    >> - cayenne uses less jdbc features than druid.
    >> - cayenne uses more try/catch to fix drivers problems.
    >>
    >> Maybe, what you are missing is that druid has dbms adapters too
    >> (called
    > SqlAdapters).
    >> The SqlAdapter interface is located in druid.interfaces and a basic
    > implementation is
    >> located in druid.core.jdbc.BasicSqlAdapter.
    >>
    >> Usually, what I do is to provide a module interface and a working
    >> prototipe to
    > allow
    >> other developers to write other modules. Inside
    >> mod.dbms.mckoi.sql.adapter there
    >> is the McKoi adapter which is able to retrive sequences and the
    >> source code
    > from views.
    >> As you can see, cayenne is not able to do this.
    >
    > Got the point. Anyway yesterday I almost finished writing the module
    > (I have
    > some problems with data types, but I am working on it. By the way, the
    > code is
    > incredibly clear, congratulations) and maybe I can post it somewhere...
    >
    >> I see only one problem here, the exception rised by JayBird, because
    >> as you
    > say the
    >> standard driver for SQL server works. Furthermore, if I can remember,
    >> the standard
    >> firebird driver is interclient. In that case I prefer to fix problems
    >> there
    > and not with jaybird.
    >
    > Mmm. Let's make things clear. The other JDBC driver for SQL server is
    > jTDS, not
    > JayBird.
    > Interclient is the official JDBC driver for INTERBASE! JayBird is the
    > official
    > JDBC driver for Firebird and only JayBird works with Firebird 1.5.
    >
    > See you
    > Antonio
    >
    > P.S. Sorry Andrea, I am using a web mail system, and it does not
    > complain the
    > "reply to" field, so for error I mailed this letter to you personal
    > address.
    >
    >



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