This was originally posted in French here.
There’s no string function in MySQL (and many other databases!) to help you find the number of occurrences of a string within another string. For example, how many times does « abc » appear in « abcbcbabcbacbcabcababcabacb » ?
I was asked this question on IRC a long time ago. Some poor soul was trying to find a particular subsequence in a genomic string (for instance « TAT ») in the …[Lire plus...]