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 following sequence :
Obviously, you can use your favorite programming language and do
this kind of search programmatically but is there a way to do it
Luckily, the answer is yes! The solution is simple and
looks like …[Lire plus]