Image thumbnails - How do I control how many child image thumbnails are presented in a table view that lists parent records?


This is somewhat of a loaded question. I started out with a child table, related to a parent table, where the child table stored 1 or more related images. At this stage the images were uploaded into the child records as blobs.

When I created a table view of the parent records and included the thumbnail of the child record images, each of the thumbnails for the parent record were displayed vertically within the column (because I configured the column that way, as opposed to specifying comma separation). This was OK but, ideally, I wanted to filter the thumbnail records so that only the first image of each parent was displayed in the table. I couldn't work out how to do this, so I just put it on hold and accepted the way it was, for the time being.

HOWEVER, when I subsequently changed the child image table to store URLs to externally stored images (as opposed to blobs within the records), I subsequently discovered that the display behaviour now seems to be different. What I now see in the view of the parent table is the first thumbnail, plus just a small section of the top of the second thumbnail below it. As it happens, this is almost exactly what I ultimately wanted to achieve, except it looks a bit messy that a part of the second thumbnail is shown.

There are consequently two parts to this post, the first is really a question as to whether or not this difference in display behaviour is supposed to be happening?

The second question is whether anyone could suggest how I should approach properly achieving what I require, without relying on what currenly appears to be a slight anomaly within Knack.

Any advice gratefully received.

Kind regards,


Hi, whilst the question still remains as to why a table would display multiple child record uploaded image thumbnails differently to the thumbnails of externally stored images, I have now worked around the underlying requirement I had in a different way.

In case anyone is interested, or if it might prove useful to anyone else trying to acheive the same, I gave up on trying to display just the first child image within the table view of the parent records and, instead, included the same image columns within the parent record as that of the child records, with slightly different field names. The table view which displays the parent record consequently now simply includes its own image URL field, instead of showing the image URL field of the child records.

The relevant fields in the parent table are now:

'Primary Image Filename' - entered by the user at time of creating the parent record.

'URL and Primary Filename' - a text formula field that concatenates a fixed URL with the filename.

'Primary Image' - an image field storing an external image URL which has a conditional rule set on it to take its value from the 'URL and Primary Filename' column.

The fields in the child record operate in an identicle fashion and are named:

'Connection to Parent'


'Image Filename'

'URL and Primary Filename'


As only a relatively small proportion of the parent records will feature multiple images, I didn't want the user to have create a parent record and then a create a primary image child record as separate operations. Consequently, there is a rule on the form for adding new parent records to automatically create a child image record at the same time, setting the Image Filename value within the new child record from the form value of Primary Image Filename.

The View Parent Record page includes a 3 column List at the top to page, to diplay display all the images associated with the parent. I then added an extra menu option called 'Image Maintenance'. The page this menu option brings up features a Table, listing the images for the parent. The table rows includes a 'delete' link so that images can be removed and re-added, if necessary. There are a further two menu buttons on this page, one entitled 'Add Image' and another entitled 'Add/Reset Primary Image'. 'Add Image' simply adds an extra child record, to cater for the requirement to store multiple images against a particular parent record. 'Add/Reset Primary Image' also adds a new child record, but additionally has a rule to update the parent record field 'Primary Image Filename', taking its value from the child's Image Filename form value.

So, that's the workaround, but the question remains as to why a table view should diplay child images differently, when using an uploaded image vs an image URL.