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

from e in Employees

select new {e.LoginID, e.JobTitle}

Employees
   .Select (
      e =>
         new
         {
            LoginID = e.LoginID,
            JobTitle = e.JobTitle
         }
   )

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 (
      e =>
         new
         {
            ID = e.LoginID,
            Title = e.JobTitle
         }
   )

SELECT DISTINCT e.JobTitle

FROM HumanResources.Employee AS e

(from e in Employees

select e.JobTitle).Distinct()

Employees
   .Select (e => e.JobTitle)
   .Distinct ()

SELECT e.*

FROM HumanResources.Employee AS e

WHERE e.LoginID = 'test'

from e in Employees

where e.LoginID == "test"

select e

Employees
   .Where (e => (e.LoginID == "test"))

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
   .Where (e => ((e.LoginID == "test") && e.SalariedFlag))

SELECT e.*
FROM HumanResources.Employee AS e

WHERE e.VacationHours >= 2 AND e.VacationHours <= 10

from e in Employees

where e.VacationHours >= 2 && e.VacationHours <= 10

select e

Employees
   .Where (e => (((Int32)(e.VacationHours) >= 2) && ((Int32)(e.VacationHours) <= 10)))

SELECT e.*

FROM HumanResources.Employee AS e
ORDER BY e.NationalIDNumber

from e in Employees

orderby e.NationalIDNumber

select e

Employees
   .OrderBy (e => e.NationalIDNumber)

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
   .OrderByDescending (e => e.HireDate)
   .ThenBy (e => e.NationalIDNumber)

SELECT e.*
FROM HumanResources.Employee AS 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
   .Where (e => (e.JobTitle.StartsWith ("Vice") || (e.JobTitle.Substring (0, 3) == "Pro")))

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
   .GroupBy (e => e.JobTitle)
   .Select (
      g =>
         new
         {
            JobTitle = g.Key,
            TotalVacations = g.Sum (e => (Int32)(e.VacationHours))
         }
   )

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
   .GroupBy (e => e.JobTitle)
   .Where (g => (g.Count () > 2))
   .Select (
      g =>
         new
         {
            JobTitle = g.Key,
            TotalVacations = g.Sum (e => (Int32)(e.VacationHours))
         }
   )

SELECT *

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) =>
         new
         {
            p = p,
            pr = pr
         }
   )

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
   .Join (
      ProductReviews,
      p => p.ProductID,
      pr => pr.ProductID,
      (p, pr) =>
         new
         {
            p = p,
            pr = pr
         }
   )

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
   .Join (
      ProductCostHistories,
      p =>
         new
         {
            ProductID = p.ProductID,
            StartDate = p.SellStartDate
         },
      pch =>
         new
         {
            ProductID = pch.ProductID,
            StartDate = pch.StartDate
         },
      (p, pch) =>
         new
         {
            p = p,
            pch = pch
         }
   )

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
   .GroupJoin (
      ProductReviews,
      p => p.ProductID,
      pr => pr.ProductID,
      (p, prodrev) =>
         new
         {
            p = p,
            prodrev = prodrev
         }
   )

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 (
      p =>
         new
         {
            ID = p.ProductID
         }
   )
   .Union (
      ProductReviews
         .Select (
            pr =>
               new
               {
                  ID = pr.ProductReviewID
               }
         )
   )

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
   .Where (p => (p.StandardCost < 100))
   .Take (10)

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
   .Where (
      p =>
         ProductReviews
            .Where (pr => (pr.Rating == 5))
            .Select (pr => pr.ProductID)
            .Contains (p.ProductID)
   )

SQL/LINQ/Lamda的更多相关文章

  1. SQL/LINQ/Lamda 写法[转发]

    SQL LINQ Lambda SELECT * FROM HumanResources.Employee from e in Employees select e Employees   .Sele ...

  2. SQL Linq lamda区别

    SQL LINQ Lambda SELECT * FROM HumanResources.Employee from e in Employees select e Employees   .Sele ...

  3. SQL,LINQ,Lambda语法对照图（转载）

    如果你熟悉SQL语句,当使用LINQ时,会有似曾相识的感觉.但又略有不同.下面是SQL和LINQ,Lambda语法对照图 SQL LINQ Lambda SELECT * FROM HumanReso ...

  4. SQL,Linq,Lambda之间的转换练习

    1.查询Student表中的所有记录的Sname.Ssex和Class列. SQL:select sname,ssex,class from Students linq:from s in Stude ...

  5. LINQ / LINQ to SQL / LINQ to XXX 它们到底有什么区别

    LINQ是新生事物,不过从不少文章和讨论上看来,这方面的概念也已经有点混沌不清了.因此我们经常可以看到这样的话: LINQ只能将数据表与实体属性一一对应…… LINQ开发指南:在LINQ中进行数据库字 ...

  6. SQL&&LINQ:左（外）连接，右（外）连接，内连接，完全连接，交叉连接，多对多连接

    SQL: 外连接和内连接: 左连接或左外连接:包含左边的表的所有行,如果右边表中的某行没有匹配,该行内容为空(NULL) --outer jion:left join or left outer jo ...

  7. Linq lamda表达式Single和First方法

      让我们来看看如何对一个整数数组使用 Single 操作符.这个整数数组的每个元素代表 2 的 1 到 10 次方.先创建此数组,然后使用 Single 操作符来检索满足 Linq Lambda表达 ...

  8. sql linq lambda 对比

    . 查询Student表中的所有记录的Sname.Ssex和Class列. select sname,ssex,class from student Linq: from s in Students ...

  9. linq lamda

    var query6 = CustomerList.SelectMany(c => c.Orders);var query6= from c in CustomerList            ...

随机推荐

  1. SAML : A SAML stack

    http://nzpcmad.blogspot.co.nz/2013/06/saml-saml-stack.html You have an application – .NET, JAVA what ...

  2. 动态改变actionbar上menu的图标

    工作中遇到了一个需求是,在滚动的时候让actionbar上的图标进行变色.实现后在这里总结下思路. 一.先在主题中定义好Actionbar的style <style name="App ...

  3. android studio 使用SVN 锁定文件，防止别人修改（基于Android studio 1.4 ）

    首先假设开发 A , 和 开发 B , 在使用 SVN 进行项目管理.那么A如何才能 某个锁定文件,防止B修改. 1.第一步,给这个文件加锁    完成这一步,则这个文件就别锁定了. 2.第二步,假如 ...

  4. Android.mk相关知识

    Android.mk是Android提供的一种makefile文件,用来指定诸如编译生成so库名.引用的头文件目录.需要编译的.c/.cpp文件和.a静态库文件等.要掌握jni,就必须熟练掌握Andr ...

  5. iOS： setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key name.

     这里指抛出一个假设:   如 果你在 storyboard中, 通过 Ctrl - Drag 方式声明了一个 @property , 但你又觉得 在 Ctrl - Drag 时 ,命名的proper ...

  6. lambda浅尝

    很久没写日志了,今天动动手记录下刚刚弄了一遍的lambda. 配置module下的build.gradle android { ... // 版本有要求 buildToolsVersion " ...

  7. iOS Xcode编译报错问题解决办法汇总

    1. 编译出现错误:linker command failed with exit code 1 第一种方法:找到Build settings->Linking->Other Linker ...

  8. java文件复制函数

    在写代码中,经常会需要复制文件.这时候就可以把这些函数放到工具类里面. 下面是一个复制文件的函数: public class CopyFileUtil { private static String ...

  9. 使用AS3输出ByteArray为16进制

    package { import flash.utils.ByteArray; /** * 输出ByteArray为16进制 * @author Rise */ public class Byte2H ...

  10. JAVA NIO中的Channels和Buffers

    前言 Channels和Buffers是JAVA NIO里面比较重要的两个概念,NIO正是基于Channels和Buffers进行数据操作,且数据总是从Channels读取到Buffers,或者从Bu ...