LtQuery

LtQuery is a ORM focus on Easy-to-use and Performance.

LtQuery does not accept the input of SQL which is a string. Instead, call giving a diverty, tiny query object.

var blogQuery = Lt.Query<Blog>().Where(_ => _.Id == Lt.Arg<int>());
var blog = connection.QuerySingle(blogQuery, new { Id = blogId });

var postsQuery = blogQuery.To<Post>(_ => _.BlogId);
var posts = connection.Query(postsQuery, new{ Id = blogId });

Benchmark

'benchmarks/OrmPerformanceTests' result.
May be, wrong the settings. I don't think it's so fast.

Measurement environment

• Windows
• SQL Server 2019 Express on local.
• LtQuery 0.1.0, Dapper 2.0.78, EFCore 5.0.5

SelectOne from Single table

SelectAll(10,000) from Single table

Performance-aware code

In LtQuery, when the user holds the query object, the optimized process is executed when the second time Later.

// hold query object
private Query<Blog> _query;

public Blog Find(int id)
{
  if(_query == null)
    _query = Lt.Query<Blog>().Where(_ => _.Id == Lt.Arg<int>()).ToImmutable();
  return _connection.QuerySingle(_query, new{ Id = id });
}

Query-Object and Method Responsibility Segregation

In LtQuery, Query-Object may differ from the general concept.
Query-Object represents the "Region" of target data.
That is, The count function in SQL is not included in Query-Object.

Policy

Aiming for the best ORM for DDD which compromises that eliminates infrastructure dependence but relies on Lazy-Loading.