ADO - LINQ to DataSet vs Entity Framework vs Raw ADO.NET

1. What each one actually is

ADO.NET (raw)

  • Low-level data access API

  • You write SQL manually

  • You control connections, commands, transactions

LINQ to DataSet

  • LINQ on top of ADO.NET DataSet/DataTable

  • In-memory querying only

  • Still disconnected, still ADO.NET

Entity Framework (EF / EF Core)

  • Full ORM (Object-Relational Mapper)

  • Maps tables → classes

  • Generates SQL automatically

2. Architecture comparison

Feature ADO.NET LINQ to DataSet Entity Framework
SQL required Yes No (for queries) Optional
Works on DB directly Yes No Yes
In-memory queries Manual Yes Yes
Object mapping Manual No Automatic
Change tracking Manual Basic Advanced
Performance control Maximum Medium Lowest

3. Raw ADO.NET (baseline)

SqlCommand cmd = new SqlCommand(
    "SELECT * FROM Users WHERE Age > @age", conn);

cmd.Parameters.Add("@age", SqlDbType.Int).Value = 18;

Pros

✔ Fastest
✔ Full SQL control
✔ Predictable execution

Cons

❌ Verbose
❌ Manual mapping
❌ More boilerplate

Used when: performance is critical, complex SQL, bulk operations.

4. LINQ to DataSet (what it really does)

var adults = dataTable.AsEnumerable()
    .Where(r => r.Field<int>("Age") > 18);

Important fact