I am interested in exporting a subset of values from a MySQL database into a JSON-formatted file on disk.
I found a link that talks about a possible way to do this:
as described in the link, it only returns (as I mentioned) 15 results. (fwiw, I checked these results against the 4000 I'm supposed to get, and these 15 are the same as the first 15 of the 4000)
That's because mysql restricts the length of the data returned by group concat to the value set in @@group_concat_max_len as soon as it gets to the that amount it truncates and returns what it's gotten so far.
You can set @@group_concat_max_len in a few different ways. reference The mysql documentation...