Question

I use ASP.NET Web API and Repository pattern.
And I want to add where clause dynamically. Like,

//controller
  static readonly ICustomerRepository repository = new CustomerRepository();
  //
 var result = repository.GetAll();

 if (form['name'] != null) result.Where( p => p.custName.Contains( form['name'].toString() ) );
 if (form['attribute1'] != null) result.Where( p => p.attribute1.Equals( form['attribute1'].toString() ) );
 return result;
//

Isn’t there any afraid of IOs?

Answer 1

Isn’t there any afraid of IOs?

It’s not really clear what you mean, but the query will only be sent to the database when you try to execute it – which is presumably in some of the code which calls your method. It’s not like it’s going to execute once for GetAll, then once for the first Where clause, then once for the second Where clause. It will all be packaged into a single query, when you start fetching the data from the IQueryable<>.