描述：查詢城市是a打頭和城市包含a的顧客並按照顧客名字排序，相同的顧客資訊不會過濾
查詢句法：
var 連線並且不過濾相同項= (from c in ctx.customers where c.city.contains("a") select c).concat
(from c in ctx.customers where c.contactname.startswith("a") select c).orderby(c => c.contactname);
對應sql：
select [t3].[customerid], [t3].[companyname], [t3].[contactname], [t3].[contacttitle], [t3].[address], [t3].[city], [t3].[region], [t3].[postalcode], [t3].[country], [t3].[phone], [t3].[fax]
from (
select [t2].[customerid], [t2].[companyname], [t2].[contactname], [t2].[contacttitle], [t2].[address], [t2].[city], [t2].[region], [t2].[postalcode], [t2].[country], [t2].[phone], [t2].[fax]
from (
select [t0].[customerid], [t0].[companyname], [t0].[contactname], [t0].[contacttitle], [t0].[address], [t0].[city], [t0].[region], [t0].[postalcode], [t0].[country], [t0].[phone], [t0].[fax]
from [dbo].[customers] as [t0]
where [t0].[city] like @p0
union all
select [t1].[customerid], [t1].[companyname], [t1].[contactname], [t1].[contacttitle], [t1].[address], [t1].[city], [t1].[region], [t1].[postalcode], [t1].[country], [t1].[phone], [t1].[fax]
from [dbo].[customers] as [t1]
where [t1].[contactname] like @p1
) as [t2]
) as [t3]
order by [t3].[contactname]
-- @p0: input string (size = 3; prec = 0; scale = 0) [%a%]
-- @p1: input string (size = 2; prec = 0; scale = 0) [a%]
取相交項
描述：查詢城市是a打頭的顧客和城市包含a的顧客的交集，並按照顧客名字排序
查詢句法：
var 取相交項= (from c in ctx.customers where c.city.contains("a") select c).intersect
(from c in ctx.customers where c.contactname.startswith("a") select c).orderby(c => c.contactname);
對應sql：
select [t1].[customerid], [t1].[companyname], [t1].[contactname], [t1].[contacttitle], [t1].[address], [t1].[city], [t1].[region], [t1].[postalcode], [t1].[country], [t1].[phone], [t1].[fax]
from (
select distinct [t0].[customerid], [t0].[companyname], [t0].[contactname], [t0].[contacttitle], [t0].[address], [t0].[city], [t0].[region], [t0].[postalcode], [t0].[country], [t0].[phone], [t0].[fax]
from [dbo].[customers] as [t0]
) as [t1]
where (exists(
select null as [empty]
from [dbo].[customers] as [t2]
where ([t1].[customerid] = [t2].[customerid]) and ([t2].[contactname] like @p0)
)) and ([t1].[city] like @p1)
order by [t1].[contactname]
-- @p0: input string (size = 2; prec = 0; scale = 0) [a%]
-- @p1: input string (size = 3; prec = 0; scale = 0) [%a%]
排除相交項
描述：查詢城市包含a的顧客並從中刪除城市以a開頭的顧客，並按照顧客名字排序
查詢句法：
var 排除相交項= (from c in ctx.customers where c.city.contains("a") select c).except
(from c in ctx.customers where c.contactname.startswith("a") select c).orderby(c => c.contactname);
對應sql：
select [t1].[customerid], [t1].[companyname], [t1].[contactname], [t1].[contacttitle], [t1].[address], [t1].[city], [t1].[region], [t1].[postalcode], [t1].[country], [t1].[phone], [t1].[fax]
from (
select distinct [t0].[customerid], [t0].[companyname], [t0].[contactname], [t0].[contacttitle], [t0].[address], [t0].[city], [t0].[region], [t0].[postalcode], [t0].[country], [t0].[phone], [t0].[fax]
from [dbo].[customers] as [t0]
) as [t1]
where (not (exists(
select null as [empty]
from [dbo].[customers] as [t2]
where ([t1].[customerid] = [t2].[customerid]) and ([t2].[contactname] like @p0)
))) and ([t1].[city] like @p1)
order by [t1].[contactname]
-- @p0: input string (size = 2; prec = 0; scale = 0) [a%]
-- @p1: input string (size = 3; prec = 0; scale = 0) [%a%]
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