Allows you to efficiently compose an IEnumerable<T> in your Entity Framework Core queries when using the SQL Server Database Provider. This is accomplished by using the AsQueryableValues extension method available on the DbContext class. Everything is evaluated on the server with a single round trip, in a way that preserves the query's execution plan, even when the values behind the IEnumerable<T> are changed on subsequent executions.
🤔💭 TLDR; By using QueryableValues, you can incorporate in-memory collections into your EF queries with outstanding performance and flexibility.
This library allows you to efficiently compose an IEnumerable<T> in your Entity Framework Core queries when using the SQL Server Database Provider. You can accomplish this by using the AsQueryableValues extension method that's available on the DbContext class. The query is processed in a single round trip to the server, in a way that preserves its execution plan, even when the values within the IEnumerable<T> are changed on subsequent executions.
Highlights
✨ Enables the composition of in-memory data within your queries, utilizing both simple and complex types.
QueryableValues is distributed as a NuGet Package. The major version number of this library is aligned with the version of Entity Framework Core by which it's supported (e.g. If you are using EF Core 5, then you must use version 5 of QueryableValues).
Configuration
Look for the place in your code where you are setting up your DbContext and calling the UseSqlServer extension method, then use a lambda expression to access the SqlServerDbContextOptionsBuilder provided by it. It is on this builder that you must call the UseQueryableValues extension method as shown in the following simplified examples:
When using the OnConfiguring method inside your DbContext:
using BlazarTech.QueryableValues;
public class MyDbContext : DbContext
{
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlServer(
"MyConnectionString",
sqlServerOptionsBuilder =>
{
sqlServerOptionsBuilder.UseQueryableValues();
}
);
}
}
When setting up the DbContext at registration time using dependency injection:
using BlazarTech.QueryableValues;
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<MyDbContext>(optionsBuilder => {
optionsBuilder.UseSqlServer(
"MyConnectionString",
sqlServerOptionsBuilder =>
{
sqlServerOptionsBuilder.UseQueryableValues();
}
);
});
}
}
💡 UseQueryableValues offers an optional options delegate for additional configurations.
How Do You Use It?
The AsQueryableValues extension method is provided by the BlazarTech.QueryableValues namespace; therefore, you must add the following using directive to your source code file for it to appear as a method of your DbContext instance:
using BlazarTech.QueryableValues;
💡 If you access your DbContext via an interface, you can also make the AsQueryableValues extension methods available on it by inheriting from the IQueryableValuesEnabledDbContext interface.
Below are a few examples composing a query using the values provided by an IEnumerable<T>.
// Sample values.
IEnumerable<int> values = Enumerable.Range(1, 10);
// Example #1 (LINQ method syntax)
var myQuery1 = dbContext.MyEntities
.Join(
dbContext.AsQueryableValues(values),
i => i.MyEntityID,
v => v,
(i, v) => new
{
i.MyEntityID,
i.PropA
}
);
// Example #2 (LINQ query syntax)
var myQuery2 =
from i in dbContext.MyEntities
join v in dbContext.AsQueryableValues(values) on i.MyEntityID equals v
select new
{
i.MyEntityID,
i.PropA
};
Complex Type Example
💡 Must be an anonymous or user-defined type with one or more simple type properties, including Boolean.
// Performance Tip:
// If your IEnumerable<T> item type (T) has many properties, project only
// the ones you need to a new variable and use it in your query.
var projectedItems = items.Select(i => new { i.CategoryId, i.ColorName });
// Example #1 (LINQ method syntax)
var myQuery1 = dbContext.Product
.Join(
dbContext.AsQueryableValues(projectedItems),
p => new { p.CategoryId, p.ColorName },
pi => new { pi.CategoryId, pi.ColorName },
(p, pi) => new
{
p.ProductId,
p.Description
}
);
// Example #2 (LINQ query syntax)
var myQuery2 =
from p in dbContext.Product
join pi in dbContext.AsQueryableValues(projectedItems) on new { p.CategoryId, p.ColorName } equals new { pi.CategoryId, pi.ColorName }
select new
{
p.ProductId,
p.Description
};
About Complex Types
⚠️ All the data provided by this type is transmitted to the server; therefore, ensure that it only contains the properties you need for your query. Not following this recommendation will degrade the query's performance.
⚠️ There is a limit of up to 10 properties for any given simple type (e.g. cannot have more than 10 Int32 properties). Exceeding that limit will cause an exception and may also suggest that you should rethink your strategy.
