Linq to sql 是一个代码生成器和ORM工具,他自动为我们做了很多事情,这很容易让我们对他的性能产生怀疑。但是也有几个测试证明显示在做好优化的情况下,linq to sql的性能可以提升到ado.net datareader性能的93%。 因此我总结了Linq to sql的10个性能提升点,来优化其查询和修改的性能。 1. 不需要时要关闭 Dat...
LINQ to SQL 中的安全性 序列化 預存程序 異動支援 SQL-CLR 類型不符 SQL-CLR 自訂類型對應 使用者定義的函式 參考 範例 閱讀英文 儲存 新增至集合 新增至計劃 列印 TwitterLinkedInFacebook電子郵件 發行項 2024/02/23 13 位參與者 意見反應 您使用與 LINQ 相同的語法,可以定義 LINQ to SQL 查詢。 唯一的...
LINQ to SQL, a component of Visual Studio Code Name "Orcas", provides a run-time infrastructure for managing relational data as objects without losing the ability to query. It does this by translating language-integrated queries into SQL for execution by the database, and then translating the ...
In LINQ to SQL, the data model of a relational database is mapped to an object model expressed in the programming language of the developer. When the application runs, LINQ to SQL translates into SQL the language-integrated queries in the object model and sends them to the database for exe...
Notice above how we are using the "OrderDetails" collection that LINQ to SQL has created for us on each Product class (because of the 1 to many relationship we modeled in the LINQ to SQL designer). Visualizing LINQ to SQL Queries in the Debugger ...
下面的代码示例采用设计用于存储已编译查询的 Queries,并采用表示强类型化 DataContext 的Northwind 类。 VB 复制 Class Queries Public Shared CustomersByCity As _ Func(Of Northwnd, String, IQueryable(Of Customer)) = _ CompiledQuery.Compile(Function(db As Northwnd, _ city As String) _ From c In ...
Public Function GetCustomersByCity(city As String) _ As IEnumerable(Of Customer) Dim db As Northwind = New Northwind() Return Queries.CustomersByCity(myDb, city) End Function SQL 翻译LINQ to SQL 实际上不执行查询;关系数据库会这样做。 LINQ to SQL 将你编写的查询转换为等效的 SQL 查询,并将其发...
LINQ to Entities 查詢可以組成兩種不同的語法:查詢表達式語法和方法型查詢語法。 查詢表達式語法是 C# 3.0 和 Visual Basic 9.0 的新功能,它是由一組以類似 Transact-SQL 或 XQuery 的宣告式語法所撰寫的子句所組成。 不過,.NET Framework Common Language Runtime (CLR) 無法讀取查詢表達式語法本身。 因此,在...
If your database has thousands of rows of orders, you do not want to retrieve them all to process a small subset. In LINQ to SQL, theEntitySet<TEntity>class implements theIQueryableinterface. This approach makes sure that such queries can be executed remotely. Two major benefits flow from...
But that does create a separate problem: if you want to get the new values from the database and want your object overwritten, simply querying will not do. DataContext will faithfully execute the queries and bring back the rows with new data for old objects b...