How to count items in comma separated list MySQL

zerkms' solution works, no doubt about that. But your problem is created by an incorrect database schema, as Steve Wellens pointed out. You should not have more than one value in one column because it breaks the first normal law. Instead, you should make at least two tables. For instance, let's say that you have members who own animals :

table member (member_id, member_name)
table member_animal (member_id, animal_name)

Even better: since many users can have the same type of animal, you should create 3 tables :

table member (member_id, member_name)
table animal (animal_id, animal_name)
table member_animal (member_id, animal_id)

You could populate your tables like this, for instance :

member (1, 'Tomas')
member (2, 'Vincent')
animal (1, 'cat')
animal (2, 'dog')
animal (3, 'turtle')
member_animal (1, 1)
member_animal (1, 3)
member_animal (2, 2)
member_animal (2, 3)

And, to answer your initial question, this is what you would do if you wanted to know how many animals each user has :

SELECT member_id, COUNT(*) AS num_animals
FROM member
INNER JOIN member_animal
    USING (member_id)
INNER JOIN animal
    USING (animal_id)
GROUP BY member_id;

There is no built-in function that counts occurences of substring in a string, but you can calculate the difference between the original string, and the same string without commas:

LENGTH(fooCommaDelimColumn) - LENGTH(REPLACE(fooCommaDelimColumn, ',', ''))

It was edited multiple times over the course of almost 8 years now (wow!), so for sake of clarity: the query above does not need a + 1, because OPs data has an extra trailing comma.

While indeed, in general case for the string that looks like this: foo,bar,baz the correct expression would be

LENGTH(col) - LENGTH(REPLACE(col, ',', '')) + 1