Raw SQL Query without DbSet - Entity Framework Core

Question

With Entity Framework Core removing dbData.Database.SqlQuery<SomeModel> I can't find a solution to build a raw SQL Query for my full-text search query that will return the tables data and also the rank.

The only method I've seen to build a raw SQL query in Entity Framework Core is via dbData.Product.FromSql("SQL SCRIPT"); which isn't useful as I have no DbSet that will map the rank I return in the query.

Any Ideas???

Answer 1

It depends if you're using EF Core 2.1 or EF Core 3 and higher versions.

If you're using EF Core 2.1

If you're using EF Core 2.1 Release Candidate 1 available since 7 may 2018, you can take advantage of the proposed new feature which is Query type.

What is query type?

In addition to entity types, an EF Core model can contain query types, which can be used to carry out database queries against data that isn't mapped to entity types.

When to use query type?

Serving as the return type for ad hoc FromSql() queries.

Mapping to database views.

Mapping to tables that do not have a primary key defined.

Mapping to queries defined in the model.

So you no longer need to do all the hacks or workarounds proposed as answers to your question. Just follow these steps:

First you defined a new property of type DbQuery<T> where T is the type of the class that will carry the column values of your SQL query. So in your DbContext you'll have this:

public DbQuery<SomeModel> SomeModels { get; set; }

Secondly use FromSql method like you do with DbSet<T>:

var result = context.SomeModels.FromSql("SQL_SCRIPT").ToList();
var result = await context.SomeModels.FromSql("SQL_SCRIPT").ToListAsync();

Also note that DdContexts are partial classes, so you can create one or more separate files to organize your 'raw SQL DbQuery' definitions as best suits you.

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If you're using EF Core 3.0 and higher versions

Query type is now known as Keyless entity type. As said above query types were introduced in EF Core 2.1. If you're using EF Core 3.0 or higher version you should now condider using keyless tntity types because query types are now marked obsolete.

This feature was added in EF Core 2.1 under the name of query types. In EF Core 3.0 the concept was renamed to keyless entity types. The [Keyless] Data Annotation became available in EFCore 5.0.

We still have the same scenarios as for query types for when to use keyless entity type.

So to use it you need to first mark your class SomeModel with [Keyless] data annotation or through fluent configuration with .HasNoKey() method call like below:

public DbSet<SomeModel> SomeModels { get; set; }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<SomeModel>().HasNoKey();
}

After that configuration, you can use one of the methods explained here to execute your SQL query. For example you can use this one:

var result = context.SomeModels.FromSqlRaw("SQL SCRIPT").ToList();