Thread: RE: JDBC driver writes binary data ONLY as Large Obj ect

Hmmm, I see your point. There must be some way of encoding the string so
that the data is stored correctly. I know certain control characters can be
stored (cr/lf's etc) as I have a PHP script that does it here.

Is it the new String(bytes[]) bit that barfs, or is it that the data is
mungled when it's re-read from the table?

Peter

--
Peter Mount
Enterprise Support
Maidstone Borough Council
Any views stated are my own, and not those of Maidstone Borough Council


-----Original Message-----
From: Bill [mailto:bouma@cplane.com]
Sent: Wednesday, August 02, 2000 8:57 PM
To: Peter Mount
Cc: pgsql-interfaces@postgresql.org
Subject: Re: [INTERFACES] JDBC driver writes binary data ONLY as Large
Object


Peter Mount wrote:

> The problem here is that there is no metadata available to check.
>
> If the backend was able to precompile the query, then we would know the
> column type, but as it stands currently there is no way of finding out
what
> the column type is.
>
> Peter

Ok.  Suppose there was metadata available.  How would you
rewrite the function PreparedStatement.writeBytes() such that
it writes the bytes directly into the column?  Since that class
does everything through heavy use of String manipulation, I
can't see how to do it.  Is there a way?  I tried this:
 public void setBytes(int parameterIndex, byte x[]) throws SQLException {     set(parameterIndex, new String(x)); }

It barfed.

Bill

Peter Mount wrote:

> Hmmm, I see your point. There must be some way of encoding the string so
> that the data is stored correctly. I know certain control characters can be
> stored (cr/lf's etc) as I have a PHP script that does it here.
>
> Is it the new String(bytes[]) bit that barfs, or is it that the data is
> mungled when it's re-read from the table?

-------------------------------------------
java.sql.SQLException: ERROR:  parser: parse error at or near ""
       at org.postgresql.Connection.ExecSQL(Connection.java, Compiled Code)       at
org.postgresql.jdbc2.Statement.execute(Statement.java,Compiled Code)
 
       at org.postgresql.jdbc2.Statement.executeUpdate(Statement.java:73)       at
org.postgresql.jdbc2.PreparedStatement.executeUpdate(PreparedStatement.java:126)

-------------------------------------------

Perhaps we can look at the ResultSet.getBytes() and just do the inverse of
that?  Though I haven't tested if getBytes() is doing the right thing yet,
either.
In the end I need to be able to store/retrieve the data through both JDBC and
ODBC interface.  This is working now if I store all binary data as Large
Objects.  But most of my blobs of binary are only 200-2000 bytes long.  I
assume it is much less efficient to store such small blobs as LOs?   That is,
assuming the driver code is written well.  So that may not be true with the
current JDBC driver given that it would first have to convert the binary
blob into a String. 8^(

Bill