MySQL 8.0

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CREATE TABLE example
    (`item_id` int, `name` varchar(20), `value` varchar(20))
;
    
INSERT INTO example
    (`item_id`, `name`, `value`)
VALUES
    (1, 'berries', '3.5-7.5'),
    (2, 'are', '2.4-4.3'),
    (3, 'very', '6.1-9.4'),
    (4, 'tasty', '4.8-7.7'),
    (5, 'fruits', '3.3-7.1'),
    (6, 'truly', '10.1-123.4')
;
SELECT * FROM example;


item_id
name
value


1
berries
3.5-7.5

2
are
2.4-4.3

3
very
6.1-9.4

4
tasty
4.8-7.7

5
fruits
3.3-7.1

6
truly
10.1-123.4


SELECT item_id, name, 
       0.0+SUBSTRING_INDEX(value, '-',1) first,
       0.0+SUBSTRING_INDEX(value, '-', -1) last
 FROM example;
       


item_id
name
first
last


1
berries
3.5
7.5

2
are
2.4
4.3

3
very
6.1
9.4

4
tasty
4.8
7.7

5
fruits
3.3
7.1

6
truly
10.1
123.4


SELECT item_id, name, first, last
  FROM (       SELECT item_id, name, 
                      0.0+SUBSTRING_INDEX(value, '-',1) first,
                      0.0+SUBSTRING_INDEX(value, '-', -1) last
                 FROM example
       ) s
 WHERE first > 2.5
   AND last < 7.2;


item_id
name
first
last


5
fruits
3.3
7.1

item_id	name	value
1	berries	3.5-7.5
2	are	2.4-4.3
3	very	6.1-9.4
4	tasty	4.8-7.7
5	fruits	3.3-7.1
6	truly	10.1-123.4