This will give you a result set that you can use for comparison. Test step 1: Execute the SQL query: First, execute the SQL query in your database management tool, such as SQL Server Management Studio or MySQL Workbench. So step 5 is the testing phase, in which you typically could follow these steps to verify that your LINQ is giving the expected results: It is only common sense that, after you’ve setup your LINQ code AND verified that it compiles into proper code, you will test if the outcomes of the SQL and the LINQ are similar. With LINQ, the query is generated and setup, but only executed when you actually perform an action on it.Īs visible in the LINQ example from step 3, the result variable will only get the information after a method like “ToList()” is performed on the LINQ query.īy setting a breakpoint on this line, you can compile and execute the query and check if this works properly.Īny typos or references to non-existing properties or entities should also have been long signalled by your IDE, as type-checking and compile time checks really form a nice way to filter out human mistakes. Step 4: Compiling & Executing the LINQ query In this LINQ query, we’re selecting the OrderID, CustomerName, and OrderDate properties from the Orders entity, using the Customer navigation property to get the associated CustomerName.īy using the navigation property instead of an explicit Join, the ORM can generate the appropriate SQL query behind the scenes, optimizing the query execution and simplifying the code for the developer. Protected override void OnModelCreating(DbModelBuilder modelBuilder) Public class NorthwindDataContext : DbContext Here is an example of a data context class coded as the representation of a database that our example query would use: A data context class provides a connection to the database and maps database objects to C# classes.Ī data context class can be created manually by you, or when you’re using Entity Framework (EF), you can generate a *data context class *using that.

This results in a list of Orders from new to old, that haven’t been shipped yet and have a freight amount of at least 100.ĭepending on your needs, and what is already implemented in your solution, you might need to create a data context class. The results are ordered by the OrderDate in descending order. The query retrieves the OrderID, CustomerName, and OrderDate from the Orders and Customers tables, where the ShippedDate is null and the Freight is greater than 100.

For example, for our example query the explanation would be: When I know what the query does functionally, I write down the query’s functionality in my own words. Then I’d look up / Google any functions or constructions that aren’t clear to me, so I can get a grasp of the functionality. Enter fullscreen mode Exit fullscreen mode

Convert linq to sql query c online