我有以下数组输出：
array (size=102)
0 =>
object(stdClass)
public 'MapId' => string '1' (length=1)
public 'Id' => string '1' (length=1)
1 =>
object(stdClass)
public 'MapId' => string '1' (length=1)
public 'Id' => string '2' (length=1)
3 =>
object(stdClass)
public 'MapId' => string '2' (length=1)
public 'Id' => string '3' (length=1)
4 =>
object(stdClass)
public 'MapId' => string '2' (length=1)
public 'Id' => string '4' (length=1)
现在我想要做的是获得MapId 1 MapId的所有数组迭代，然后所有迭代的2 array_map() while等等。
我不确定是否应该为foreach创建函数，在DECLARE @Test TABLE ( ID NVARCHAR(10),Number INT )
INSERT INTO @Test VALUES ('TG32',6)
INSERT INTO @Test VALUES ('TG32',6)
INSERT INTO @Test VALUES ('TG32',6)
INSERT INTO @Test VALUES ('TG32',2)
INSERT INTO @Test VALUES ('QD65',2)
INSERT INTO @Test VALUES ('QD65',3)
INSERT INTO @Test VALUES ('QD65',3)
INSERT INTO @Test VALUES ('HT76',7)
INSERT INTO @Test VALUES ('HT76',1)
INSERT INTO @Test VALUES ('HT76',5)
DECLARE @Categories TABLE ( ID NVARCHAR(10), Item NVARCHAR(10) )
INSERT INTO @Categories (ID, Item) VALUES
( 'TG32', 'Hats' ),
( 'QD65', 'Coats' ),
( 'HT76', 'Shoes' ),
( 'WR52', 'Shirts' )
SELECT C.Item, ISNULL(S.Number, 0) AS 'Number'
FROM @Categories C
LEFT JOIN @Test S ON C.ID = S.ID
循环中使用SELECT C.Item, SUM(ISNULL(S.Number, 0)) AS 'Number'
FROM @Categories C
LEFT JOIN @Test S ON C.ID = S.ID
GROUP BY C.Item
循环，或者PHP是否具有简单的本机函数可以做这样的事情。
有人可以说明如何做到这一点吗？