BlobOp.write

glong write(gda.blob.Blob blob, glong offset)

Writes a chunk of bytes from a blob to the BLOB accessible through op, blob is unchanged after this call.

If blob has an associated #GdaBlobOp (ie. if blob->op is not null) then the data to be written using op is the data fetched using blob->op.

`blob`	a #GdaBlob which contains the data to write
`offset`	offset to write from the start of the blob (starts at 0)

the number of bytes written. In case of error, -1 is returned and the

provider should have added an error to the connection.