var q = .OrderBy(c => c.City) .ThenBy(c => c.ContactName).ToList();在T-SQL中没有ThenBy语句,其依然翻译为OrderBy,所以也可以用下面语句来表达:var q = db.Customers .OrderBy(c => c.ContactName) .OrderBy(c => c.City).ToList();所要注意的是,多个OrderBy操作时,级连方式是按逆序。
10.多列(Multiple Columns) 28 11.表达式(Expression) 29 LINQ to SQL语句(7)之Exists/In/Any/All/Contains 29 Exists/In/Any/All/Contains操作符 29 Any 29 1.简单形式: 29 2.带条件形式: 30 All 30 Contains 31 1.包含一个对象: 31 2.包含多个值: 32 LINQ to SQL语句(8)之Concat/Union/Intersect...
.OrderBy(c => c.City) .ThenBy(c =>c.ContactName).ToList(); 在T-SQL 中没有 ThenBy 语句,其依然翻译为 OrderBy,所以也可以用下面语句来表达: var q = db.Customers .OrderBy(c => c.ContactName) .OrderBy(c => c.City).ToList (); 所要注意的是,多个 OrderBy 操作时,级连方式是按逆序。
LINQ to SQL语句(1)之Where LINQ to SQL语句(2)之Select/Distinct LINQ to SQL语句(3)之Count/Sum/Min/Max/Avg LINQ to SQL语句(4)之Join LINQ to SQL语句(5)之Order By LINQ to SQL语句(6)之Group By/Having LINQ to SQL语句(7)之Exists/In/Any/All/Contains LINQ to SQL语句(8)之Concat/Union/...
查询表达式由一组用类似于 SQL 或 XQuery 的声明性语法所编写的子句组成。 每个子句依次包含一个或多个 C# 表达式,而这些表达式可能本身就是查询表达式,或者包含查询表达式。查询表达式必须以 from 子句开头,且必须以 select 或group 子句结尾。 在第一个 from 子句与最后一个 select 或group 子句之间,可以包含以下...
Azure Cosmos DB for NoSQL documentation Overview Introduction FAQ Understand distributed NoSQL Try Azure Cosmos DB free Azure AI Advantage free trial Get started Build AI Applications Create secure solutions Model data for partitioning Develop modern applications ...
LINQ presents to programmers a unified and consistent API for data access from heterogeneous data sources, such as:In-memory object graphs Active Directory entries Flickr pictures and XML SQL ServerThe LINQ provider allows the user to access business data by using .NET managed languages....
LINQ to SQL applications are easy to get started. Objects linked to relational data can be defined just like normal objects, only decorated with attributes to identify how properties correspond to columns. Of course, it is not even necessary to do this by hand. A design-time tool is provid...
Multiple Mappings There are many SQL Server data types that you can map to one or more CLR data types. There are also many CLR types that you can map to one or more SQL Server types. Although a mapping may be supported by LINQ to SQL, it does not mean that the two types mapped be...
C# Linq Group By on multiple columns C# LINQ List<KeyValuePair<string, KeyValuePair<int, int>>> Group by to List<KeyValuePair<string, List<KeyValuePair<int, int>>> C# LINQ one condition, return multiple columns and rows C# LINQ order by not working for a SQL table with a primary ke...