合并两个 SELECT 查询并在一张表中显示数据？

Question

以下查询显示来自两个表的数据，它工作正常，但我想合并结果并在单个表中显示输出：

SELECT 
    ITEM_MODEL, QUANTITY 
FROM
    ITEMS_MASTER 
WHERE 
    ITEM_MODEL = 'keyboard' 

SELECT
    AVG(RATE) AS Avg_Rate,
    SUM(AMOUNT) AS TOTAL_AMOUNT 
FROM
    ITEM_DETAILS 
WHERE
    ITEM_MODEL = 'keyboard' 
GROUP BY 
    ITEM_MODEL

可能的方法是什么我对 SQL 很陌生，所以请指导我如何做到这一点。提前致谢。我正在使用 SQL Server 2012。

Answer 1

我刚刚接受了您的两个查询并编译为一个。这只是其中一种方法

select 
   m.ITEM_MODEL,
   m.QUANTITY,
   d.Avg_Rate,
   d.TOTAL_AMOUNT 
from 
   (Select ITEM_MODEL, AVG(RATE) as Avg_Rate,SUM(AMOUNT) as TOTAL_AMOUNT 
    from ITEM_DETAILS 
    where ITEM_MODEL= 'keyboard' Group by ITEM_MODEL) D 
    inner join 
    ITEMS_MASTER m on m.ITEM_MODEL = d.ITEM_MODEL

它将仅显示“键盘”，因为您的聚合内联查询已经排除了所有其他查询。我也将Item_master 移到第二位以获得更好的性能

Answer 2

试试这个

Select ITEM_MODEL,QUANTITY 
from ITEMS_MASTER t join(
                           Select ITEM_MODEL,AVG(RATE) as Avg_Rate,SUM(AMOUNT) as                               TOTAL_AMOUNT from ITEM_DETAILS 
where ITEM_MODEL= 'keyboard' Group by ITEM_MODEL
) s 
on s.item_model = t.item_model
where ITEM_MODEL='keyboard'