Asynchronous Querying Edit on GitHub

Linq Operators

Marten adds extension methods to IQueryable for the asynchronous invocation of the common Linq operators:

• AnyAsync()
• CountAsync()
• MinAsync()
• MaxAsync()
• AverageAsync()
• SumAsync()
• LongCountAsync()
• FirstAsync()/FirstOrDefaultAsync()
• SingleAsync()/SingleOrDefaultAsync()
• ToListAsync()

An example usage of ToListAsync() is shown below:

[Fact]
public async Task use_to_list_async_in_query()
{
    theSession.Store(new User { FirstName = "Hank" });
    theSession.Store(new User { FirstName = "Bill" });
    theSession.Store(new User { FirstName = "Sam" });
    theSession.Store(new User { FirstName = "Tom" });

    await theSession.SaveChangesAsync().ConfigureAwait(false);

    var users = await theSession
        .Query<User>()
        .Where(x => x.FirstName == "Sam")
        .ToListAsync().ConfigureAwait(false);

    users.Single().FirstName.ShouldBe("Sam");
}

Querying by SQL

To query for results with user-supplied SQL, use:

var users =
    await
        session.QueryAsync<User>(
                   "select data from mt_doc_user where data ->> 'FirstName' = 'Jeremy'")
               .ConfigureAwait(false);
var user = users.Single();