MySQL 5.7

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CREATE TABLE owner (id int);
INSERT INTO owner (id) VALUES (1), (2);
CREATE TABLE phones(id int, owner_id int, numbers varchar(15));
INSERT INTO phones(id, owner_id, numbers)
VALUES (1,1,'333-555-888')
,(2,1,'222-777-666')
,(3,1,'555-657-555')
,(4,2,'123123')
,(5,2,'222222');

Records: 2  Duplicates: 0  Warnings: 0



Records: 5  Duplicates: 0  Warnings: 0


SELECT * FROM owner;
SELECT * FROM phones;


id


1

2




id
owner_id
numbers


1
1
333-555-888

2
1
222-777-666

3
1
555-657-555

4
2
123123

5
2
222222


SELECT o.id, p.numbers, @rn := @rn + 1 AS rn
FROM owner o
INNER JOIN phones p ON o.id = p.owner_id
CROSS JOIN (SELECT @rn := 0) r
WHERE o.id=1


id
numbers
rn


1
333-555-888
1

1
222-777-666
2

1
555-657-555
3


SET @sql = NULL;
SELECT GROUP_CONCAT(
 CONCAT('(SELECT numbers FROM phones WHERE owner_id = o.id ORDER BY numbers LIMIT 1 OFFSET ',rn - 1,' ) AS numbers', rn) 
 ) INTO @sql
FROM (SELECT o1.id, p.numbers, @rn := @rn + 1 AS rn
FROM owner o1
INNER JOIN phones p ON o1.id = p.owner_id
CROSS JOIN (SELECT @rn := 0) r
WHERE o1.id=(SELECT owner_id FROM (SELECT owner_id, COUNT(1) AS cnt FROM phones GROUP BY owner_id) c ORDER BY cnt DESC LIMIT 1)) phones;
SET @sql = CONCAT('SELECT o.id, ', @sql, ' FROM owner o -- WHERE id = 2');

-- SELECT @sql;
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

Statement prepared




id
numbers1
numbers2
numbers3


1
222-777-666
333-555-888
555-657-555

2
123123
222222
null