Inserting into BLOB field

[cmathrusse]

I know this has been asked before...

I need to perform an insert into a BLOB field. Previously my field was
defined as a CLOB and there was no issue. But due to a new requirement I
need to change this to a BLOB. The issue that I have now is that I cannot
insert any seed data into this field with a SQL script.

Is there any way that I would be able to perform these inserts using a SQL
script?

Thanks...

[Kristian Waagan]

Post by cmathrusse
I know this has been asked before...
I need to perform an insert into a BLOB field. Previously my field was
defined as a CLOB and there was no issue. But due to a new requirement I
need to change this to a BLOB. The issue that I have now is that I cannot
insert any seed data into this field with a SQL script.

Hi,

Does the following thread help?
http://www.nabble.com/VALUES-expression%2C-BLOB%2C-and-using-ij-tp10778754p10778754.html


Regards,

[cmathrusse]

I had read that post prior and it would require me converting the text that I
am attempting to insert, an xslt file, into a hex representation. Only then
could I attempt to do this. I did actually attempt this. (not very friendly)
I did convert the contents of my file into a hex representation and
attempted the insert by performing a CAST( X'text content' AS BLOB), but it
complained when I executed the SQL. While this would be a viable approach, I
think you would agree that this is far from desirable.

What would be optimal would be the ability to have Derby allow inserts of
TEXT into BLOB fields. I know that this is how Sybase ASE operates, (Yes, I
know Derby is not ASE) and I don't know if this is ANSI standard, but it
sure makes life less complicated.

[Rick Hillegas]

Often these coercion problems can be finessed by writing your own cast
function. You might try the following:

1) Write a public static method which takes a String argument and
returns a java.sql.Blob value.

2) Register that method as a Derby function which takes a VARCHAR
argument and returns a BLOB.

3) Then use the function to coerce string values to Blobs in your insert
statements.

Here's some code which shows how to do this. First the static method:

import java.sql.Blob;
import org.apache.derbyTesting.functionTests.tests.lang.StringColumnVTI;

public class z
{
public static Blob makeBlob( String seed )
{
return new StringColumnVTI.SimpleBlob( seed.getBytes() );
}
}

Then a little ij script which exercises the function:

connect 'jdbc:derby:memory:dummy;create=true';

create function makeBlob( seed varchar( 32672 ) )
returns blob
language java
parameter style java
no sql
external name 'z.makeBlob';

create table t( a blob );

insert into t( a ) values ( makeBlob( 'xyz' ) );

select * from t;


Hope this helps,
-Rick

Post by cmathrusse
I had read that post prior and it would require me converting the text that I
am attempting to insert, an xslt file, into a hex representation. Only then
could I attempt to do this. I did actually attempt this. (not very friendly)
I did convert the contents of my file into a hex representation and
attempted the insert by performing a CAST( X'text content' AS BLOB), but it
complained when I executed the SQL. While this would be a viable approach, I
think you would agree that this is far from desirable.
What would be optimal would be the ability to have Derby allow inserts of
TEXT into BLOB fields. I know that this is how Sybase ASE operates, (Yes, I
know Derby is not ASE) and I don't know if this is ANSI standard, but it
sure makes life less complicated.

...

[Rick Hillegas]

I forgot to mention that you this will only work on 10.5, which includes
the fix for DERBY-2201.

Regards,
-Rick

Post by Rick Hillegas
Often these coercion problems can be finessed by writing your own cast
1) Write a public static method which takes a String argument and
returns a java.sql.Blob value.
2) Register that method as a Derby function which takes a VARCHAR
argument and returns a BLOB.
3) Then use the function to coerce string values to Blobs in your
insert statements.
import java.sql.Blob;
import org.apache.derbyTesting.functionTests.tests.lang.StringColumnVTI;
public class z
{
public static Blob makeBlob( String seed )
{
return new StringColumnVTI.SimpleBlob( seed.getBytes() );
} }
connect 'jdbc:derby:memory:dummy;create=true';
create function makeBlob( seed varchar( 32672 ) )
returns blob
language java
parameter style java
no sql
external name 'z.makeBlob';
create table t( a blob );
insert into t( a ) values ( makeBlob( 'xyz' ) );
select * from t;
Hope this helps,
-Rick

Post by cmathrusse
I had read that post prior and it would require me converting the text that I
am attempting to insert, an xslt file, into a hex representation. Only then
could I attempt to do this. I did actually attempt this. (not very friendly)
I did convert the contents of my file into a hex representation and
attempted the insert by performing a CAST( X'text content' AS BLOB), but it
complained when I executed the SQL. While this would be a viable approach, I
think you would agree that this is far from desirable.
What would be optimal would be the ability to have Derby allow inserts of
TEXT into BLOB fields. I know that this is how Sybase ASE operates, (Yes, I
know Derby is not ASE) and I don't know if this is ANSI standard, but it
sure makes life less complicated.

...