SQL/LINQ的的GroupBy与最小值，并根据列

我与这些例子行的表：SQL/LINQ的的GroupBy与最小值，并根据列

 
CouponID ShopID ShopLongitude ShopLatitude 
365  1881 55,5574105 9,9613295 
365  23550 55,5510846 9,9936818 
365  33550 55,6220936 10,0663895 
365  33551 55,5573436 9,9611765 
366  1881 55,5574105 9,9613295 
366  23550 55,5510846 9,9936818 
367  1881 55,5574105 9,9613295 
533  1881 55,5574105 9,9613295 
533  23550 55,5510846 9,9936818 
533  33550 55,6220936 10,0663895 
533  33551 55,5573436 9,9611765 
354  1881 55,5574105 9,9613295 
354  23550 55.5510846 9,9936818 
354  33550 55,6220936 10,0663895 
354  33551 55,5573436 9,9611765

我想有结果，每最近ShopID CouponID

我已经有查询：

SELECT CouponID, MIN (dbo.DistanceBetween (53.54613,9.98537,ShopLatitude,ShopLongitude)) as distance 
FROM Table 
GROUP BY CouponID 
ORDER BY CouponID, distance ASC

输出该CouponID并向ShopID的最小距离为每个优惠券：

 
CouponID distance 
354  0,778524633472375 
365  0,778524633472375 
366  0,778524633472375 
367  2,02548179145764

在LINQ的语句如下：

var coupon = (from c in dbContext.table 
         group c by c.CouponID into cgrp 
         select new 
         { 
         CouponID = cgrp.Key, 
         Distance = cgrp.Min(c => DistanceBetween(latitude, longitude, c.ShopLatitude, c.ShopLongitude)) 
         }) 
         .OrderBy(c => c.CouponID).ThenBy(c => DistanceBetween(latitude, longitude, c.ShopLatitude, c.ShopLongitude));

我怎么也拿回相关ShopID从查询和LINQ声明的最小距离？

来源

2013-03-27 freakdev

SELECT c.CouponID, c.ShopID, nearest.distance 
FROM 
Coupons C JOIN 
(
    SELECT CouponID, MIN (dbo.DistanceBetween (53.54613,9.98537,ShopLat,ShopLon)) as distance 
    FROM Coupons 
    GROUP BY CouponID 
) nearest on c.CouponID = nearest.CouponID 
      AND dbo.DistanceBetween (53.54613,9.98537,ShopLat,ShopLon) = nearest.distance 
ORDER BY CouponID, distance ASC

来源

2013-03-27 17:34:41 GalacticJello

只是修改您的SQL查询来执行分组并加入你想要的。

创建一个表来保存距离，然后选择couponid和shopid匹配的min。

来源

2013-03-27 16:58:00

SQL/LINQ的的GroupBy与最小值，并根据列

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