If you have this relationship:
TableA::matchField = TableB::matchfield
Then, from a layout based on TableA, this expression is true only if there is at least one related record in Table B:
Not IsEmpty ( tableB::matchfield )
You can actually refer to any field in TableB that is not empty for any given record in that table. The matchfield is never empty so it makes a good choice for this expression.
If matchfield is of type number, you can simplify that expression to:
To get exactly the same results
So far so good. Now to best figure how to determine whether or not an external file exists or not. My current logic compares record count but in this case I don't have that ability so I was wondering if there is a better method to determine if an external file (ie. aciadmin.an0) truly exists without attempting to import.
Exit Loop If [file exist is true]
What kind of "external file"?
A FileMaker File?
A File to be inserted in a container field?
A File from which you will import data?
An xml file from which I will import data, which is essence is my response file from an external web service.
Ah yes, something we discussed in another thread...
I wonder if FileMaker can "see" that file if it is in the process of being downloaded, but the download is not yet complete. That's not something that I can test easily on my system.
FileMaker can check the list of files in a folder if the enclosing folder is inside the documents folder. There are a number of plug ins that can list the contents of any folder on your computer and there are ways to use a system script to list the contents of a folder. The details of the last option depend on the OS that you are using.
I ended up changing my net framework program to build the file with a different extention, then rename it once it was completed so I don't attempt to import from an incomplete file, so I'm good for now.