T-SQL - 将列传递给子查询以进行过滤

Question

我需要将一列传递给子查询进行过滤，但我似乎无法让它工作。

我知道如果我的子查询要返回一个列，那么我可以重新排列我的查询并且它会起作用，但我需要子查询返回 3 列。

到目前为止，这是我的查询及其抱怨：

 where c.location.STDistance(l.location) is not null
 order by c.Location.STDistance(l.location) 

与

无法绑定多部分标识符“l.location”。

select
    l.*, city.*
from  
    listings l, 
    (select top 1 c.UnicodeName, c.name, r.code as region, cn.code as country 
     from cities c
     inner join regions r on r.regionid = c.regionid
     inner join Countries cn on cn.CountryId = r.countryid
     where c.location.STDistance(l.location) is not null
     order by c.Location.STDistance(l.location)) as city

实际计划 https://www.brentozar.com/pastetheplan/?id=BkiRk-74P

城市和列表索引

CREATE SPATIAL INDEX [256_HHHH] ON [dbo].[Listings]
(
    [Location]
)USING  GEOGRAPHY_GRID 
WITH (GRIDS =(LEVEL_1 = HIGH,LEVEL_2 = HIGH,LEVEL_3 = HIGH,LEVEL_4 = HIGH), 
CELLS_PER_OBJECT = 256, PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
GO

CREATE SPATIAL INDEX [16_HHHH] ON [dbo].[Listings]
(
    [Location]
)USING  GEOGRAPHY_GRID 
WITH (GRIDS =(LEVEL_1 = HIGH,LEVEL_2 = HIGH,LEVEL_3 = HIGH,LEVEL_4 = HIGH), 
CELLS_PER_OBJECT = 16, PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
GO

Answer 1

您所描述的是横向连接，其中连接的子查询使用listing 表中的列。这会因为from 子句中的逗号而失败：某些数据库确实可以识别这种隐式横向连接，但不能识别 SQL Server。

您必须明确连接类型（无论如何这是最佳做法）：使用cross apply。

select l.*, city.*
from  listings l
cross apply (
     select  top (1)  c.UnicodeName, c.name, r.code as region, cn.code as country from cities c
     inner join regions r on r.regionid = c.regionid
     inner join Countries cn on cn.CountryId = r.countryid
     where c.location.STDistance(l.location) is not null
     order by c.Location.STDistance(l.location) 
 ) as city