[转]SQL,LINQ,Lambda语法对照图
如果你熟悉SQL語句,當使用LINQ時,會有似曾相識的感覺.但又略有不同.下面是SQL和LINQ,Lambda語法對照圖
| SELECT * FROM HumanResources.Employee | from e in Employees select e | Employees |
| SELECT e.LoginID, e.JobTitle FROM HumanResources.Employee AS e | from e in Employees select new {e.LoginID, e.JobTitle} | Employees |
| SELECT e.LoginID AS ID, e.JobTitle AS Title FROM HumanResources.Employee AS e | from e in Employees select new {ID = e.LoginID, Title = e.JobTitle} | Employees |
| SELECT DISTINCT e.JobTitle FROM HumanResources.Employee AS e | (from e in Employees select e.JobTitle).Distinct() | Employees |
| SELECT e.* FROM HumanResources.Employee AS e WHERE e.LoginID = 'test' | from e in Employees where e.LoginID == "test" select e | Employees |
| SELECT e.* FROM HumanResources.Employee AS e WHERE e.LoginID = 'test' AND e.SalariedFlag = 1 | from e in Employees where e.LoginID == "test" && e.SalariedFlag select e | Employees |
| SELECT e.* WHERE e.VacationHours >= 2 AND e.VacationHours <= 10 | from e in Employees where e.VacationHours >= 2 && e.VacationHours <= 10 select e | Employees |
| SELECT e.* FROM HumanResources.Employee AS e | from e in Employees orderby e.NationalIDNumber select e | Employees |
| SELECT e.* FROM HumanResources.Employee AS e ORDER BY e.HireDate DESC, e.NationalIDNumber | from e in Employees orderby e.HireDate descending, e.NationalIDNumber select e | Employees |
| SELECT e.* WHERE e.JobTitle LIKE 'Vice%' OR SUBSTRING(e.JobTitle, 0, 3) = 'Pro' | from e in Employees where e.JobTitle.StartsWith("Vice") || e.JobTitle.Substring(0, 3) == "Pro" select e | Employees |
| SELECT SUM(e.VacationHours) FROM HumanResources.Employee AS e | Employees.Sum(e => e.VacationHours); | |
| SELECT COUNT(*) FROM HumanResources.Employee AS e | Employees.Count(); | |
| SELECT SUM(e.VacationHours) AS TotalVacations, e.JobTitle FROM HumanResources.Employee AS e GROUP BY e.JobTitle | from e in Employees group e by e.JobTitle into g select new {JobTitle = g.Key, TotalVacations = g.Sum(e => e.VacationHours)} | Employees |
| SELECT e.JobTitle, SUM(e.VacationHours) AS TotalVacations FROM HumanResources.Employee AS e GROUP BY e.JobTitle HAVING e.COUNT(*) > 2 | from e in Employees group e by e.JobTitle into g where g.Count() > 2 select new {JobTitle = g.Key, TotalVacations = g.Sum(e => e.VacationHours)} | Employees |
| SELECT * FROM Production.Product AS p, Production.ProductReview AS pr | from p in Products from pr in ProductReviews select new {p, pr} | Products |
| SELECT * FROM Production.Product AS p INNER JOIN Production.ProductReview AS pr ON p.ProductID = pr.ProductID | from p in Products join pr in ProductReviews on p.ProductID equals pr.ProductID select new {p, pr} | Products |
| SELECT * FROM Production.Product AS p INNER JOIN Production.ProductCostHistory AS pch ON p.ProductID = pch.ProductID AND p.SellStartDate = pch.StartDate | from p in Products join pch in ProductCostHistories on new {p.ProductID, StartDate = p.SellStartDate} equals new {pch.ProductID, StartDate = pch.StartDate} select new {p, pch} | Products |
| SELECT * FROM Production.Product AS p LEFT OUTER JOIN Production.ProductReview AS pr ON p.ProductID = pr.ProductID | from p in Products join pr in ProductReviews on p.ProductID equals pr.ProductID into prodrev select new {p, prodrev} | Products |
| SELECT p.ProductID AS ID FROM Production.Product AS p UNION SELECT pr.ProductReviewID FROM Production.ProductReview AS pr | (from p in Products select new {ID = p.ProductID}).Union( from pr in ProductReviews select new {ID = pr.ProductReviewID}) | Products |
| SELECT TOP (10) * FROM Production.Product AS p WHERE p.StandardCost < 100 | (from p in Products where p.StandardCost < 100 select p).Take(10) | Products |
| SELECT * FROM [Production].[Product] AS p WHERE p.ProductID IN( ????SELECT pr.ProductID ????FROM [Production].[ProductReview] AS [pr] ????WHERE pr.[Rating] = 5 ????) | from p in Products where (from pr in ProductReviews where pr.Rating == 5 select pr.ProductID).Contains(p.ProductID) select p | Products |
?
轉自:http://hi.baidu.com/ren_long_/blog/item/4c574455a37e570e3b293518.html?
轉載于:https://www.cnblogs.com/rohan/archive/2011/01/18/1937925.html
總結
以上是生活随笔為你收集整理的[转]SQL,LINQ,Lambda语法对照图的全部內容,希望文章能夠幫你解決所遇到的問題。
- 上一篇: [PM Tools]软件项目进度跟踪表v
- 下一篇: (重要)java都是值传递,与对象形参所