| Subject | Re: How to find the size of the contents of a blob? |
|---|---|
| Author | Adam |
| Post date | 2007-10-25T23:35:25Z |
--- In firebird-support@yahoogroups.com, "mlq97" <mlq@...> wrote:
text blob, then you may be able to do something by casting it to a
varchar first and using the shipped UDFs, but you are using PDFs.
You could write your own UDF function that accepted a BLOB and
returned the size in bytes, but this requires the database engine to
retrieve the entire blob and pass it to your dll to then count every
time you want to get the number of bytes.
It is easier and quicker to actually store the size in the same table.
If you wrote the UDF I mentioned in the previous paragraph, you could
even do this silently using before insert and before update triggers,
or require the client application to tell you.
Adam
>blob?
> I am storing PDF files in Blobs.
> Is it possible to use a query to find the size of the contents of a
> If so, how does one do this?From what I can tell, it is not possible out of the box. If it was a
text blob, then you may be able to do something by casting it to a
varchar first and using the shipped UDFs, but you are using PDFs.
You could write your own UDF function that accepted a BLOB and
returned the size in bytes, but this requires the database engine to
retrieve the entire blob and pass it to your dll to then count every
time you want to get the number of bytes.
It is easier and quicker to actually store the size in the same table.
If you wrote the UDF I mentioned in the previous paragraph, you could
even do this silently using before insert and before update triggers,
or require the client application to tell you.
Adam