I tuoi dati sono alquanto difficili da gestire.
Per creare una tabella pivot le colonne devono essere uniche, anzi, potrebbero apparire anche cinque ki.
È piuttosto brutto e funziona con myslq 5.7
Schema (MySQL v5.7)
CREATE TABLE employees (
`id` INTEGER,
`emp` VARCHAR(5)
);
INSERT INTO employees
(`id`, `emp`)
VALUES
('1', 'emp-A'),
('2', 'emp-B'),
('3', 'emp-C');
CREATE TABLE relatives (
`id` INTEGER,
`emp_id` INTEGER,
`relation` VARCHAR(6),
`relative` VARCHAR(8),
`birthdate` DATE
);
INSERT INTO relatives
(`id`, `emp_id`, `relation`, `relative`, `birthdate`)
VALUES
('1', '1', 'spouse', 'spouse-A', '1970-01-01'),
('2', '1', 'kid', 'kid-A1', '1971-01-02'),
('3', '1', 'kid', 'kid-A2', '1972-01-01'),
('4', '1', 'kid', 'kid-A3', '1973-01-01'),
('5', '2', 'spouse', 'spouse-B', '1980-02-01'),
('6', '2', 'kid', 'kid-B1', '1981-02-01'),
('7', '2', 'kid', 'kid-B2', '1982-02-01'),
('8', '3', 'kid', 'kid-C1', '1991-03-01'),
('9', '3', 'kid', 'kid-C2', '1992-03-01');
Richiesta n. 1
SELECT
GROUP_CONCAT(DISTINCT
CONCAT(
'MAX(case when `relation` = "',
`relation`,
'" then `relation` end) AS `',
relation, '`',
',MAX(case when `relation` = "',
`relation`,
'" then `birthdate` end) AS `',
'birthdate_',relation, '`'
)
ORDER BY rownumber
) INTO @sql
FROM
(SELECT
`relation`
,rownumber
FROM
employees e
INNER JOIN
(SELECT
IF(`relation` = 'kid',IF (@empid = `emp_id`,@rn:= @rn+1,@rn:= 1),IF (@empid = `emp_id`,@rn:= @rn,@rn:= 0)) rownumber
,IF(`relation` = 'kid',CONCAT(`relation`,@rn),`relation`) relation
, `relative`
, `birthdate`
,@empid := `emp_id` emp_id
FROM
(SELECT
*
FROM
relatives
ORDER BY `emp_id`,FIELD(`relation`,"spouse","kid"),`birthdate`) rel
,(SELECT @empid := 0) a1
,(SELECT @rn := 0) a2) r ON e.id = r.emp_id) t1
;
SET @sql = CONCAT("SELECT MIN(`emp`), ", @sql, "
FROM (SELECT
`emp_id`,
`emp` ,
`relation`
,rownumber
, `relative`
, `birthdate`
FROM
employees e
INNER JOIN
(SELECT
IF(`relation` = 'kid',IF (@empid = `emp_id`,@rn:= @rn+1,@rn:= 1),IF (@empid = `emp_id`,@rn:= @rn,@rn:= 0)) rownumber
,IF(`relation` = 'kid',CONCAT(`relation`,@rn),`relation`) 'relation'
, `relative`
, `birthdate`
,@empid := `emp_id` 'emp_id'
FROM
(SELECT
*
FROM
relatives
ORDER BY `emp_id`,FIELD(`relation`,'spouse','kid'),`birthdate`) rel
,(SELECT @empid := 0) a1
,(SELECT @rn := 0) a2) r ON e.id = r.emp_id) t1
GROUP BY `emp_id`");
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
| MIN(`emp`) | spouse | birthdate_spouse | kid1 | birthdate_kid1 | kid2 | birthdate_kid2 | kid3 | birthdate_kid3 |
| ---------- | ------ | ---------------- | ---- | -------------- | ---- | -------------- | ---- | -------------- |
| emp-A | spouse | 1970-01-01 | kid1 | 1971-01-02 | kid2 | 1972-01-01 | kid3 | 1973-01-01 |
| emp-B | spouse | 1980-02-01 | kid1 | 1981-02-01 | kid2 | 1982-02-01 | | |
| emp-C | | | kid1 | 1991-03-01 | kid2 | 1992-03-01 | | |
