Thanks Hunch. That works pretty well. The only issue I'm having with it now is that it's not efficient. I should have specified that I will be cycling through a few hundred substrings to count the appearance of each. Using this method, the only way I can think to make it work is with a separate query for each substring.
Is there any way I can select the entire column, store it in an array, and have php do the work of counting the appearance of the substrings within the array?