转:c# Linq 的分页[转]
轉(zhuǎn):http://www.cnblogs.com/leleroyn/archive/2008/05/14/1196811.html
很多學(xué)習(xí)Linq的朋友肯定有自己所不同的方法,考慮這個(gè)問題我所想到的是
用Take(),Skip(),TakeWhile(),SkipUntil()中的方法來實(shí)現(xiàn)
首先看Take()是否可用
Take方法的作用是從結(jié)果中取固定數(shù)量的值,
MydbDataContext mydb=new MydbDataContext("server=.;database=mydb");
var query=from p in mydb.Products ?????????????? orderby p.id descending ??????????????? select p;//取出Products中所用的項(xiàng)按降序排列 如果直接用take()
var q=query.take(n) 這樣只能取出前條n記錄,但是還是讓我們看到了分頁的曙光,還是還有個(gè)skip嗎,skip可以取出除去滿足條件的剩下的記錄。如果我們要把數(shù)據(jù)以每頁pagesize的數(shù)量來進(jìn)行分頁,很簡(jiǎn)單,很skip(pagersize*pagenum)然后在剩下的記錄中take(pagesize)不就得到了想要的數(shù)據(jù)了么。
?
varq=query.skip(pagesize*pagenum).take(pagesize) 就這么簡(jiǎn)單。
希望朋友們提供更好的方法來進(jìn)行分頁,同時(shí)對(duì)這個(gè)方法的優(yōu)劣性,進(jìn)行批評(píng)指導(dǎo) 附上運(yùn)行時(shí)生成的SQL(感謝:紫色陰影 、Boler Guo ) sql server2000: SELECT TOP 20 [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 NOT (EXISTS( SELECT NULL AS [EMPTY] FROM ( SELECT TOP 10 [t1].[CustomerID] FROM [dbo].[Customers] AS [t1] ) AS [t2] WHERE [t0].[CustomerID] = [t2].[CustomerID] )) sql server 2005 SELECT TOP 10 [t1].[CustomerID], [t1].[CompanyName], [t1].[ContactName], [t1].[ContactTitle], [t1].[Address], [t1].[City], [t1].[Region], [t1].[PostalCode], [t1].[Country], [t1].[Phone], [t1].[Fax] FROM ( SELECT ROW_NUMBER() OVER (ORDER BY [t0].[ContactName]) AS [ROW_NUMBER], [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 [t1].[ROW_NUMBER] > @p0 ORDER BY [t1].[ContactName] -- @p0: Input Int32 (Size = 0; Prec = 0; Scale = 0) [50] -- Context: SqlProvider(Sql2005) Model: AttributedMetaModel Build: 3.5.20XXX.X
轉(zhuǎn)載于:https://www.cnblogs.com/yjg8116/p/3458278.html
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