| SQL | LINQ | Lambda |
|---|---|---|
| SELECT * FROM HumanResources.Employee | from e in Employees select e | Employees .Select (e => e) |
| SELECT e.LoginID, e.JobTitle FROM HumanResources.Employee AS e | select new {e.LoginID, e.JobTitle} | .Select ( e => new { LoginID = e.LoginID, JobTitle = e.JobTitle } ) |
| SELECT e.LoginID AS ID, e.JobTitle AS Title | select new {ID = e.LoginID, Title = e.JobTitle} | ID = e.LoginID, Title = e.JobTitle |
| SELECT DISTINCT e.JobTitle | (from e in Employees select e.JobTitle).Distinct() | .Select (e => e.JobTitle) .Distinct () |
| SELECT e.* WHERE e.LoginID = 'test' | where e.LoginID == "test" | .Where (e => (e.LoginID == "test")) |
| WHERE e.LoginID = 'test' AND e.SalariedFlag = 1 | where e.LoginID == "test" && e.SalariedFlag | .Where (e => ((e.LoginID == "test") && e.SalariedFlag)) |
| WHERE e.VacationHours >= 2 AND e.VacationHours <= 10 | where e.VacationHours >= 2 && e.VacationHours <= 10 | .Where (e => (((Int32)(e.VacationHours) >= 2) && ((Int32)(e.VacationHours) <= 10))) |
| ORDER BY e.NationalIDNumber | orderby e.NationalIDNumber | .OrderBy (e => e.NationalIDNumber) |
| ORDER BY e.HireDate DESC, e.NationalIDNumber | orderby e.HireDate descending, e.NationalIDNumber | .OrderByDescending (e => e.HireDate) .ThenBy (e => e.NationalIDNumber) |
| WHERE e.JobTitle LIKE 'Vice%' OR SUBSTRING(e.JobTitle, 0, 3) = 'Pro' | where e.JobTitle.StartsWith("Vice") || e.JobTitle.Substring(0, 3) == "Pro" | .Where (e => (e.JobTitle.StartsWith ("Vice") || (e.JobTitle.Substring (0, 3) == "Pro"))) |
| SELECT SUM(e.VacationHours) | Employees.Sum(e => e.VacationHours); | |
| SELECT COUNT(*) | Employees.Count(); | |
| SELECT SUM(e.VacationHours) AS TotalVacations, e.JobTitle GROUP BY e.JobTitle | group e by e.JobTitle into g select new {JobTitle = g.Key, TotalVacations = g.Sum(e => e.VacationHours)} | .GroupBy (e => e.JobTitle) g => JobTitle = g.Key, TotalVacations = g.Sum (e => (Int32)(e.VacationHours)) |
| SELECT e.JobTitle, SUM(e.VacationHours) AS TotalVacations HAVING e.COUNT(*) > 2 | where g.Count() > 2 | .Where (g => (g.Count () > 2)) |
| FROM Production.Product AS p, Production.ProductReview AS pr | from p in Products from pr in ProductReviews select new {p, pr} | Products .SelectMany ( p => ProductReviews, (p, pr) => p = p, pr = pr |
| FROM Production.Product AS p INNER JOIN Production.ProductReview AS pr ON p.ProductID = pr.ProductID | join pr in ProductReviews on p.ProductID equals pr.ProductID | .Join ( ProductReviews, p => p.ProductID, pr => pr.ProductID, |
| INNER JOIN Production.ProductCostHistory AS pch ON p.ProductID = pch.ProductID AND p.SellStartDate = pch.StartDate | join pch in ProductCostHistories on new {p.ProductID, StartDate = p.SellStartDate} equals new {pch.ProductID, StartDate = pch.StartDate} select new {p, pch} | ProductCostHistories, p => ProductID = p.ProductID, StartDate = p.SellStartDate }, pch => ProductID = pch.ProductID, StartDate = pch.StartDate (p, pch) => pch = pch |
| LEFT OUTER JOIN Production.ProductReview AS pr ON p.ProductID = pr.ProductID | into prodrev select new {p, prodrev} | .GroupJoin ( (p, prodrev) => prodrev = prodrev |
| SELECT p.ProductID AS ID UNION SELECT pr.ProductReviewID FROM Production.ProductReview AS pr | (from p in Products select new {ID = p.ProductID}).Union( select new {ID = pr.ProductReviewID}) | ID = p.ProductID .Union ( ProductReviews .Select ( pr => new { ID = pr.ProductReviewID } ) |
| SELECT TOP (10) * WHERE p.StandardCost < 100 | where p.StandardCost < 100 select p).Take(10) | .Where (p => (p.StandardCost < 100)) .Take (10) |
| FROM [Production].[Product] AS p WHERE p.ProductID IN( SELECT pr.ProductID FROM [Production].[ProductReview] AS [pr] WHERE pr.[Rating] = 5 ) | where (from pr in ProductReviews where pr.Rating == 5 select pr.ProductID).Contains(p.ProductID) select p | .Where ( ProductReviews .Where (pr => (pr.Rating == 5)) .Select (pr => pr.ProductID) .Contains (p.ProductID) |
轉發自：http://www.cnblogs.com/babietongtianta/p/3192967.html
學習交流群：364976091