SELECT id,SUM(CASE WHEN Item='Chocolate' THEN Purchased END) as Chocolate_Purchased,
SUM(CASE WHEN Item='Biscuit' THEN Purchased END) as Biscuit_Purchased,
SUM(CASE WHEN Item='Jelly' THEN Purchased END) Jelly_Purchased,
SUM(CASE WHEN Item='Mile' THEN Purchased END) as Mile_Purchased
GROUP BY id
Zde je dynamická verze
SET @sql = NULL;
SELECT
GROUP_CONCAT(DISTINCT
CONCAT(
'SUM(IF(t.item = ''',
item,
''', t.purchased, 0)) AS ',
item
)
)INTO @sql
FROM t;
SET @sql = CONCAT('SELECT id,
', @sql, '
FROM t
GROUP BY id');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;