Last year, Scott Guthrie stated “You can actually override the raw SQL that LINQ to SQL uses if you want absolute control over the SQL executed”, but I can’t find documentation describing an extensibility method.
I would like to modify the following LINQ to SQL query:
using (NorthwindContext northwind = new NorthwindContext ()) { var q = from row in northwind.Customers let orderCount = row.Orders.Count () select new { row.ContactName, orderCount }; }
Which results in the following TSQL:
SELECT [t0].[ContactName], ( SELECT COUNT(*) FROM [dbo].[Orders] AS [t1] WHERE [t1].[CustomerID] = [t0].[CustomerID] ) AS [orderCount] FROM [dbo].[Customers] AS [t0]
To:
using (NorthwindContext northwind = new NorthwindContext ()) { var q = from row in northwind.Customers.With ( TableHint.NoLock, TableHint.Index (0)) let orderCount = row.Orders.With ( TableHint.HoldLock).Count () select new { row.ContactName, orderCount }; }
Which would result in the following TSQL:
SELECT [t0].[ContactName], ( SELECT COUNT(*) FROM [dbo].[Orders] AS [t1] WITH (HOLDLOCK) WHERE [t1].[CustomerID] = [t0].[CustomerID] ) AS [orderCount] FROM [dbo].[Customers] AS [t0] WITH (NOLOCK, INDEX(0))
Using:
public static Table<TEntity> With<TEntity> ( this Table<TEntity> table, params TableHint[] args) where TEntity : class { //TODO: implement return table; } public static EntitySet<TEntity> With<TEntity> ( this EntitySet<TEntity> entitySet, params TableHint[] args) where TEntity : class { //TODO: implement return entitySet; }
And
public class TableHint { //TODO: implement public static TableHint NoLock; public static TableHint HoldLock; public static TableHint Index (int id) { return null; } public static TableHint Index (string name) { return null; } }
Using some type of LINQ to SQL extensibility, other than this one. Any ideas?
In LINQ to SQL, the data model of the relational database is mapped to an object model and while executing the LINQ object model converted into SQL to get the required data from the database, while returning the data from the database, the LINQ to SQL will convert SQL results to LINQ objects model.
LINQ to SQL was the first object-relational mapping technology released by Microsoft. It works well in basic scenarios and continues to be supported in Visual Studio, but it's no longer under active development.
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 execution.
LINQ to SQL offers an infrastructure (run-time) for the management of relational data as objects. It is a component of version 3.5 of the . NET Framework and ably does the translation of language-integrated queries of the object model into SQL. These queries are then sent to the database for the purpose of execution.
The ability to change the underlying provider and thus modify the SQL did not make the final cut in LINQ to SQL.
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