MySQL:selecteer, groepeer op en transformeer rijen om kolommen te scheiden :)

Uw gegevens zijn wat moeilijk te verwerken.

Om een ​​draaitabel te maken, moet de kolom uniek zijn, meer nog, dat er ook vijf ki's kunnen verschijnen.

Het is behoorlijk lelijk en het werkt metmyslq 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');

Vraag #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     |      |                |

Bekijken op DB Fiddle