linq2db | Linq to database provider | SQL Database library

You can use AsUpdatable()

You have to set Server property:

For using linq2db.EntityFrameworkCore you have to switch to library's LINQ provider. It can be done by simple ToLinqToDB() call.

To substitute standard DateTime classes you have to modify your T4 template in the following way:

As was pointed out by svyatoslav-danyliv the configuration for Linq2Db by default uses CompareNullsAsValues which causes the generated SQL to include null checks on both fields.

The fix is in the constructor of your DataConnection object to define:

Linq2Db.Common.Configuration.Linq.CompareNullsAsValues = false

Solution is simple. You have to tell linq2db that this function has database analogue. For your case it is Sql.FunctionAttribute

You have two ways to approach this issue.

1. Create a view on the database level with the query you have and use it in the entity framework, then you will be able to simply do the following

CTE functionality in linq2db uses expression tree comparison to detect the same CTE in query, so you can repeat that by ExpressionMethod helper which injects lambda body into original query.

After the factory method call Transaction.Build(t, u, a), linq2db loses information about fields mapping and query become good only for materialization but not filtering. This is true for any currently available LINQ providers.

What you can do with linq2db to make code reusable - rewrite your function Transaction.Build by using ExpressionMethodAttribute: