File Attachment field as Lookup Field

I've created an example app in Exchange - called "Example - Lookup File Attachment through Many-to-Many Relationship". You can find it here:


https://www.quickbase.com/db/main?a=AppDetail&ID=1439&app_name=Example%20-%20Lookup%20File


There are 3 tables:
- Procedures - with a File Attachment field
- Issues
- Resolutions - the intermediate table in the many-to-many relationship between Procedures and Issues.

The basic set up for a Many-to-Many relationship is detailed here:
http://www.quickbase.com/user-assistance/Default.html#many_to_many_relationship.html

You cannot lookup a File Attachment field directly.
To enable a lookup to the File Attachment field (in the Procedures table) - create a Formula Text field (called "File Attachment Link" here, with HTML tags enabled) with this formula:

If ([File Attachment] = "", "",
"<a href='" & URLRoot() & "up/" & Dbid() & "/a/r" & [Record ID#] & "/e7/v0' target='_blank' >" & [File Attachment] & "</a>")

Note the "e7" portion of the formula. The "7" refers to the Field ID of the File Attachment field. Modify accordingly for your own app.

This "File Attachment Link" link field can now be looked up in the Resolution table, and also on the Issues table.

In the example app - see that Procedure A is the Resolution for Issues 1 and 2 - with the same Document A accessible from both. Procedure B is the Resolution for Issue 3. Issue 4 is resolved by both Procedure A and Procedure B.

The only real additional step in setting the relationship (on top of a normal many-to-many relationship) - is setting the File Attachment Link field. Once you have that - you can look it up normally.

So once you're in the Issue, you press "Add Resolution", and select the Procedure. Then on the Issue, you can now see the File Attachment Link for that Procedure, which you can click directly to download the document.

Hope this helps!

Did you use the Example app, or did you implement it on your own app?

In the formula for the link (which should be in the same table as where the File Attachment is located):

If ([File Attachment] = "", "",
"<a href='" & URLRoot() & "up/" & Dbid() & "/a/r" & [Record ID#] & "/e7/v0' target='_blank' >" & [File Attachment] & "</a>")

Note the "e7" portion of the formula.  The "7" refers to the Field ID of the File Attachment field.  Modify accordingly for your own app.

I suspect that the field with fid = 7 - is not the File Attachment field in your app.  Replace the "e7" with "e[fid]" - where [fid] is the fid for your File Attachment field.

Can two separate child records (Issues) be pointing to the same parent record (Procedures)?  Or in other words - can Procedure A be the resolution for both Issue B and Issue C?  (EDIT:  a 1-to-many relationship should be sufficient here:  One Procedure has many Issues).

If one Issue can have multiple Procedures, you'll need a many-to-many relationship - between Procedures and Issues.   (EDIT:  to clarify when you'd need a many-to-many relationship).

There may well be some tricky and clever ways to set this up - but I think you'd be going to a bunch of effort to avoid the most straightforward way - which is a many-to-many relationship.

Yes, we could have multiple children pointing to the same parent. I had considered a many to many but that adds additional steps in the establishment of the relationship and there might as well be an extra step in finding the document
I was thinking if there was some way to get the URL of a specific field I could pass that down as a lookup field and use that.

Thank you very much, your bit of code has enabled me to do exactly what I needed to do without all the extra steps from using Many to Many relationships!

The Formula Text field can be brought through as a lookup field into the child table.

Ok great!  If all you need is a 1-to-many relationship (One Procedure has many Issues) - then that should be sufficient.

Hi Xavier Fan,

I was able to use this in my application but when i try to click on the file attachment link I get the following error: the specified field was not a File Attachment field. Please help.

Hi Xavier fan,

Field ID was the issue I have two similar fields and I got the wrong field ID in their. Working now. Thank you so much for the quick response.

Great!

Worked perfectly for a 1 to many relationship! Thank you!!!