LINQ to SQL is used for data handling with SQL Server databases only using extension methods, while ADO.NET can handle data from any database. LINQ to SQL introduced in .NET 3.0 uses DataContext for connectivity, while ADO.NET uses connections. LINQ syntax is more complex. LINQ is an incomplete ORM that needs extensions for querying, while nHibernate is a full ORM with its own querying language. LINQ is better for small apps with less database dependence, while nHibernate is suited to large apps with heavy database usage. With LINQ the database schema exists beforehand, but nHibernate requires defining the schema. LINQ is intended for rapid app

1. 1.Difference between LINQ to SQL and ADO.NET
S.No LINQ to SQL ADO.NET
1 Used for data handling with SQL Used for data handling with any
Server databases only. database: SQL
Server/Access/Oracle/Excel etc.
2 Uses the extension methods of Does not use the extension methods of
System.Linq.Queryable class. System.Linq.Queryable class.
3 Introduced in .net Framework 3.0 It is there since the .net Framework 1.0
4 DataContext is used for Database SqlConnection/OleDbConnection are
connectivity. used for database connectivity
5 Syntax and coding is somewhat Easier syntax and coding.
complex.
Note: Both LINQ TO SQL and ADO.NET have connected / disconnected modes of data
handling
2.Difference between LINQ and nHibernate
S.No LINQ nHibernate
1 LINQ is not an open-source nHibernate is an open source.
2 LINQ is an incomplete ORM tool nHibernate is an ORM tool
as it needs additional extensions.
3 LINQ is primarily a querying nHibernate has a limited querying
language language.
4 LINQ is much more useful in nHibernate is much more useful in
small applications where there is largel applications where there is
no massive dependence on massive dependence on databases.
databases.
5 With LINQ, database already With nHibernate, database does not
exists and the relationships and already exist and it needs to be defined
some programming will be .
dependent on how the database is
defined.

2. 3.Difference between LINQ and Entity Framework
S.No LINQ Entity Framework
1 Used for Rapid Application Used for Enterprise Development
Development
2 Works with objects in database Works with Conceptual model of
database
3 Mainly woks with SQL Server Works with all data sources
4 ".dbml" is created while using ".EDMX" is created while using Entity
LINQ to SQL Framework