MySQL：提取元素的最频繁值

Question

I have a DB table with a set of Texts and, for each of them, five (5) emotions. What I need to do is to get the most frequent emotion for each group of rows, only if that emotion appears at least three times. Otherwise, I do not want to show the aggregated row in the result set. For instance I have:

text     | emotion
nice day | happyness
nice day | happyness
nice day | neutral
nice day | neutral
nice day | happyness
hello    | sadness
hello    | sadness
hello    | surprise
hello    | surprise
hello    | neutral

And the output should be: nice day | happyness
In that case, the text "Hello" is not displayed, since there are no emotions that occur at least 3 times.

I tried many solutions but I cannot find a working one...

Answer 1

This is a bit tricky:

select text, emoticon
from t
group by text, emoticon
having count(*) >= 3 and
       count(*) = (select count(*)
                   from t t2
                   where t2.text = t.text
                   group by t2.emoticon
                   order by count(*) desc
                   limit 1
                  );

Answer 2

let's say your table name is emotions so the code will be

select text,emotion
from emotions
group by text,emotion
having count(emotion)>2

The GROUP BY statement is often used with aggregate functions (COUNT, MAX, MIN, SUM, AVG) to group the result-set by one or more columns