How to display the value that repeats the most?

Question

MySQL

let's say I have:

1б2, 34, 56, 7,  7,  7,  7,  7,  7,  7, 4, 7, 3, 4, 5, 7,  7,  7

how to get only 7 from such lines for example?

Answer 1

if they are in the table:
select distinct(value) from table where value=7

Answer 2

Well, for example:

select i from t group by i order by count(*) desc limit 1;

sqlfiddle.com/#!17/d1148/1

Answer 3

In the acc array (the key is the value from the ref array), you add the current index of the ref array with a separator to the value.
In the array you find the longest list and form a string by indexes.