There are two ways you enable LINQ querying of in-memory data. If the data is of a type that implements IEnumerable<T>, you query the data by using LINQ to Objects. If it doesn't make sense to enable enumeration
If the method has System.Action or System.Func<TResult> parameters, these arguments are provided in the form of a lambda expression, as shown in the following example: C# Copy // Query #6. IEnumerable<int> largeNumbersQuery = numbers2.Where(c => c > 15); In the previous queries,...
If the method hasSystem.ActionorSystem.Func<TResult>parameters, these arguments are provided in the form of alambda expression, as shown in the following example: C# // Query #6.IEnumerable<int> largeNumbersQuery = numbers2.Where(c => c >15); ...
foreach (City city in queryMajorCities) { Console.WriteLine(city); } // Output: // City { Population = 120000 } // City { Population = 112000 } // City { Population = 150340 } // Method-based syntax IEnumerable<City> queryMajorCities2 = cities.Where(c => c.Population > 100000)...
在LINQ中,您可以使用Lambda表达式来执行IN或CONTAINS操作。以下是一个示例,展示了如何使用Lambda表达式在LINQ查询中执行IN或CONTAINS操作: 代码语言:csharp 复制 usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;classProgram{staticvoidMain(){// 示例数据List<int>numbers=newList<int>{1,2,3,4,5}...
在C中,如何利用Linq对实体集合进行筛选,获取符合一组值的元素?C# Linq获取实体查询中列表元素的in是指在使用LINQ查询时,通过使用in关键字来筛选实体列表中的元素。 具体来说,in关键字可以用于筛选一个实体属性的值是否在一个给定的列表中。以下是一个示例代码: ...
Abstract C-style languages (including C#) are imperative in nature, meaning that the emphasis is placed on the state of the system, and changes are made to that state over time. Data-acquisition languages such as SQL are functional in nature, meaning that the emphasis is placed on the opera...
// var is used for convenience in these queriesdoubleaverage = numbers1.Average();varconcatenationQuery = numbers1.Concat(numbers2);varlargeNumbersQuery = numbers2.Where(c => c >15); 示例- 混合查询和方法语法 此示例演示如何对查询子句的结果使用方法语法。 只需将查询表达式括在括号中,然后应用点...
= null join p in products on c.ID equals p?.CategoryID select new { Category = c.Name, Name = p.Name }; 在前面的示例中,where 子句筛选出类别序列中的所有 null 元素。 此方法独立于 join 子句中的 null 检查。 在此示例中,带有 null 的条件表达式有效,因为 Products.CategoryID 的类型为 ...
// var is used for convenience in these queriesdoubleaverage = numbers1.Average();varconcatenationQuery = numbers1.Concat(numbers2);varlargeNumbersQuery = numbers2.Where(c => c >15); 示例- 混合查询和方法语法 此示例演示如何对查询子句的结果使用方法语法。 只需将查询表达式括在括号中,然后应用点...