<div>
Hi,<br />
<br />
you can use the isEmpty Function &nbsp;to test if a Field is empty or not<br />
<br />
&nbsp;IF Table1.FieldByname('Custom<wbr />erName').i<wbr />sEmpty<br />
&nbsp; Then ShowMessage('Empty')<br />
&nbsp; &nbsp;Else ShowMessage('Not Emtpy');<br />
<br />
you can use with this function with querys also<br />
<br />
good luck <br />
<br />
Cesario
</div>


<div>
You have to know that in particular data bases the Blob field is not recovered in the query but appart of it (with another query managed by the BDE for example). Sometimes you have to do a new code to retreive the blob, you can find this solution on the net (use SaveToStream and LodFromStream using a TMemoryStream)
</div>


<div>
A blob field can be empty and not null.<br />
<br />
Another way to be sure is to compare the length of the string:<br />
<br />
if (Length(tbl.FieldByName('b<wbr />lobfield')<wbr />.AsString)<wbr /> &gt;&nbsp;0) then<br />
&nbsp; &nbsp;// not empty<br />
else<br />
&nbsp; // really is empty<br />
<br />
<br />
-David
</div>


<div>
just from the delphi helpfile:<br />
<br />
Indicates whether the BLOB field contains any data.<br />
<br />
property IsNull: Boolean;<br />
<br />
Description<br />
<br />
Read IsNull to determine whether the BLOB field is blank. IsNull is True if the BLOB field is empty. IsNull is False if the BLOB field contains any data.<br />
<br />
if Query1Images.IsNull then<br />
&nbsp; ShowMessage('You forgot the BLOB data!');<br />
<br />
meikl ;-)
</div>


<div>
Thankyou to all that helped with this question.<br />
<br />
I have selected the answer that was the first with working result.<br />
<br />
Sorry Cesario, but I don't have &quot;.Isempty&quot; available for the the table.<br />

</div>


<div>
<div class="content wysiwyg-content">
I am currently writing my first application which stores data in BLOB fields.<br />
<br />
I am using an access database (unfortunately), to which I can currently store and recover the blob data.<br />
<br />
The question :<br />
<br />
Is there any easy way, or a routine that I can use to test if the blob fileld in the database is empty or not ?<br />
<br />
If not, it looks like I will have to trap it by exceptions.<br />
<br />
Many Thanks in advance<br />
<br />
Paul.<br />

</div>
</div>


I am currently writing my first application which stores data in BLOB fields.

I am using an access database (unfortunately), to which I can currently store and recover the blob data.

The question :

Is there any easy way, or a routine that I can use to test if the blob fileld in the database is empty or not ?

If not, it looks like I will have to trap it by exceptions.

Many Thanks in advance

Paul.


Testing if a BLOB field is empty

Delphi is the most powerful Object Pascal IDE and component library for cross-platform Native App Development with flexible Cloud services and broad IoT connectivity. It provides powerful VCL controls for Windows 10 and enables FMX development for Windows, Mac and Mobile. Delphi is your choice for ultrafast Enterprise Strong Development™. Look for increased memory for large projects, extended multi-monitor support, improved Object Inspector and much more. Delphi is 5x faster for development and deployment across multiple desktop, mobile, cloud and database platforms including 32-bit and 64-bit Windows 10.