Dine data er lidt svære at håndtere.
For at lave et pivotbord skal kolonnerne være unikke, endnu mere, at der også kan dukke fem kis op.
Det er ret grimt, og det virker med myslq 5.7
Skema (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');
Forespørgsel #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 | | |