表别名我已在SQL查询下面,我想用核心数据做:现在SQL SELECT与核心数据
SELECT t1.date, t1.amount + SUM(t2.amount) AS importantvalue
FROM specifictable AS t1, specifictable AS t2
WHERE t1.amount < 0 AND t2.amount < 0 AND t1.date IS NOT NULL AND t2.date IS NULL
GROUP BY t1.date, t1.amount;
,它看起来像CoreData提取请求只能从单个实体获取。有没有办法在单个抓取请求中完成整个查询?
谢谢你的回复。我可能会坚持做两次抓取,因为这看起来会使当前的数据模型过度复杂化(我将不得不将现有的实体拆分为两个)。 –