mysql - 按行值排序MySQL数据

我有两张这样的桌子：
表：项目

id | itemId
---|------
0  | 1
1  | 2
2  | 3

表：项目规格

id | itemId | key          | values
---|--------|---------------
0  | 1      | itemreceived | 2012-06-01
1  | 1      | modelyear    | 1992
2  | 1      | model        | 2
3  | 2      | itemreceived | 2012-06-05
4  | 2      | modelyear    | 2003
5  | 2      | model        | 1
6  | 3      | itemreceived | 2012-07-05
7  | 3      | modelyear    | 2000
8  | 3      | model        | 3

我当前的查询如下：

SELECT items.*, item_specs.* FROM item_specs
INNER JOIN item_specs ON items.itemId = item_specs.itemId
WHERE itemId IN(1,2,3)

如何按键值排序结果，例如：model？
我要找的结果是这样的：（如果我按型号订购）

id | itemId | key          | values
---|--------|---------------
3  | 2      | itemreceived | 2012-06-05
4  | 2      | modelyear    | 2003
5  | 2      | model        | 1
0  | 1      | itemreceived | 2012-06-01
1  | 1      | modelyear    | 1992
2  | 1      | model        | 2
6  | 3      | itemreceived | 2012-07-05
7  | 3      | modelyear    | 2000
8  | 3      | model        | 3

返回的内容按具有键模型的值排序

最佳答案

你需要每行的型号。你可以通过一个join来实现：

SELECT items.*, item_specs.*
FROM item_specs
INNER JOIN item_specs ON items.itemId = item_specs.itemId
INNER JOIN item_specs aux ON (aux.key = 'model' and aux.itemID = item_specs.itemId)
WHERE item_specs.itemId IN(1,2,3)
ORDER BY aux.values/*this is the model*/, item_specs.id;

或使用子选择：

SELECT items.*,
       item_specs.*,
       (select aux.values
        from item_specs aux
        where aux.key = 'model' and aux.itemID = item_specs.itemId
        ) as model
FROM item_specs
INNER JOIN item_specs ON items.itemId = item_specs.itemId
WHERE item_specs.itemId IN(1,2,3)
ORDER BY model, item_specs.id;