Create parameterized queries

[VahidN]

This library in-lines the field's values in EF-Core queries. For instance it creates queries like this:

   WHERE [m].[Title] = N'action'

For performance reasons (caching the query plan by SQL Server) it's better to create parameterized queries such as:

   WHERE [m].[Title] =  @__p_0

[alirezanet]

Hi, Does this query translate to a parameterized Sql query using SqlServer provider?

dbContext.Blogs.Where( Param_0 =>  Param_0.Title == "action")

The thing is gridify doesn't control the provider's behavior. if you have a filter like title=action gridify generates the above query so you should see the same results in native LINQ and gridify generated expression,
I will look into this more, but first I need to find out what is causing the provider different behavior between native LINQ and gridify.

[alirezanet]

I did some research and few tests. the behavior of the Native LINQ and gridify generated expression is the same in SqlServer Provider.

// using SqlServer provider
     [Fact]
      public void ApplyFiltering_GeneratedSqlShouldMatch_SqlServerProvider()
      {
         var actual = _dbContext.Users.ApplyFiltering("name = vahid").ToQueryString();
         var expected = _dbContext.Users.Where(q => q.Name == "vahid").ToQueryString();

         Assert.Equal(expected , actual);
      }

SELECT [u].[Id], [u].[CreateDate], [u].[FkGuid], [u].[Name]
FROM [Users] AS [u]
WHERE [u].[Name] = N'vahid'

according to this test, the question is, does even this feature you mentioned exist in Entity Framework ?! if yes, how we can use it because looks like we can not use it even with Native LINQ., did I missed something?

[alirezanet]

Never mind, I found the parameterized way to do this in LINQ.
This test is failing because of additional parameter exist in the final query:

      [Fact]
      public void ApplyFiltering_GeneratedSqlShouldMatch_UsingVariable_SqlServerProvider()
      {
         var name = "vahid";
         var actual = _dbContext.Users.ApplyFiltering("name = vahid").ToQueryString();
         var expected = _dbContext.Users.Where(q => q.Name == name).ToQueryString();

         Assert.Equal(expected , actual);
      }

DECLARE @__name_0 nvarchar(4000) = N'vahid';

SELECT [u].[Id], [u].[CreateDate], [u].[FkGuid], [u].[Name]
FROM [Users] AS [u]
WHERE [u].[Name] = @__name_0

I never encountered any best practices in the entity framework that says you should always define at least a variable for your constant values!

[alirezanet]

This feature is available in version v2.2.1.
To activate Query optimization for entity framework you need to Enable the EntityFrameworkCompatibilityLayer

  GridifyGlobalConfiguration.EnableEntityFrameworkCompatibilityLayer();

---

e.g

 _dbContext.Users.ApplyFiltering("name = vahid")

when EntityFrameworkCompatibilityLayer is enable the output is

DECLARE @__Value_0 nvarchar(4000) = N'vahid';

SELECT [u].[Id], [u].[CreateDate], [u].[FkGuid], [u].[Name]
FROM [Users] AS [u]
WHERE [u].[Name] = @__Value_0