Question

我想知道是否有人可以帮助我从我的表中选择信息，但是根据订单ID对结果进行分组。我确信这很简单，但我似乎无法使代码正常工作。

这是我的尝试 - 只显示1个结果，而不是6：

使用orderid 55542
使用orderid 55543

SQL：

SELECT *
FROM #__users_orders
WHERE userid = 22 
GROUP BY orderid 
ORDER BY date DESC

任何帮助将不胜感激：）

编辑：

我想实现这个（或类似的东西）

Array[55542]
(
    [0] => stdClass Object
        (
            [id] => 6
            [userid] => 66
            [orderid] => 55542
            [date] => 2011-08-05 16:30:24
            [code] => 121021
            [title] => 7 STAR CHICKEN A/KING 71198 1.3KG
            [units] => 2
            [ctns] => 
        )

    [1] => stdClass Object
        (
            [id] => 1
            [userid] => 66
            [orderid] => 55542
            [date] => 2011-08-05 16:06:12
            [code] => 302371
            [title] =>  ANCHOVY FILL 730GM
            [units] => 2
            [ctns] => 
        )

    [2] => stdClass Object
        (
            [id] => 6
            [userid] => 66
            [orderid] => 55542
            [date] => 2011-08-05 16:30:24
            [code] => 121021
            [title] => 7 STAR CHICKEN A/KING 71198 1.3KG
            [units] => 2
            [ctns] => 
        )

    [3] => stdClass Object
        (
            [id] => 1
            [userid] => 66
            [orderid] => 55542
            [date] => 2011-08-05 16:06:12
            [code] => 302371
            [title] =>  ANCHOVY FILL 730GM
            [units] => 2
            [ctns] => 
        )

)

Array[55543]
(
    [0] => stdClass Object
        (
            [id] => 6
            [userid] => 66
            [orderid] => 55543
            [date] => 2011-08-05 16:30:24
            [code] => 121021
            [title] => 7 STAR CHICKEN A/KING 71198 1.3KG
            [units] => 2
            [ctns] => 
        )

    [1] => stdClass Object
        (
            [id] => 1
            [userid] => 66
            [orderid] => 55543
            [date] => 2011-08-05 16:06:12
            [code] => 302371
            [title] =>  ANCHOVY FILL 730GM
            [units] => 2
            [ctns] => 
        )

)

Answer 1

SELECT *
FROM #__users_orders
WHERE userid = 22 
ORDER BY orderid DESC

只需选择这样的项目，然后通过迭代结果并为每个新的orderid创建一个新数组，在前端创建对象/数组层次结构。

Answer 2

您不应在此查询中选择“*”。

按“某些列”分组时。您只能选择“某些列”或some_aggregate_function（其他列）。

e.g。如果您想获得每个订单ID的汇总订单大小和最新日期，您可以执行类似 -

的操作

SELECT orderid, sum(ordersize), max(date) FROM #__users_orders WHERE userid = 22 GROUP BY orderid ORDER BY max(date) DESC

Answer 3

SELECT orderid, COUNT(*)
FROM #__users_orders
WHERE userid = 22 
GROUP BY orderid 
ORDER BY date DESC

通常，您必须使用聚合（例如COUNT，SUM）和GROUP BY匹配。因此，SELECT中但不在COUNT或SUM中的列位于GROUP BY

中

只有MySQL允许您不遵循此规则。其他数据库引擎会出错。

Answer 4

查询似乎没问题，也许你以错误的方式提取结果

SELECT * FROM table GROUP BY field1;

应返回与

相同的行数

SELECT field1，field2 FROM table GROUP BY field1;

但数量不同于

SELECT * FROM table;

mysql select all，group by orderid

4 个答案: