MySQL SELECT RANDOM如果有数字的话

I have a table where one of the columns contains text, for which I count the words:

SELECT SUM( LENGTH(`text`) - LENGTH(REPLACE(`text`, ' ', ''))+1) AS length 
FROM tblParadigm WHERE `uuid`=$uuid;

So that I can filter rows which have below or above a certain count of words. Now I can select random rows from this table, using:

SELECT `uuid` FROM tblParadigm  ORDER BY RAND()  LIMIT 10;

My Question is, how can I combine those two, in order to select 10 random rows, which have a word count of less than $count?

Do I need a JOIN or an IF? I would prefer to do this in MySQL rather than PHP.

You may want to use the MySQL HAVING clause at the end of your first query.

Having length < 5