ObjectQuery<T>.Where(String, ObjectParameter[]) Method

Reference

Definition

Namespace:: System.Data.Objects

Assembly:: System.Data.Entity.dll

Important

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Limits the query to results that match specified filtering criteria.

public:
 System::Data::Objects::ObjectQuery<T> ^ Where(System::String ^ predicate, ... cli::array <System::Data::Objects::ObjectParameter ^> ^ parameters);

public System.Data.Objects.ObjectQuery<T> Where (string predicate, params System.Data.Objects.ObjectParameter[] parameters);

member this.Where : string * System.Data.Objects.ObjectParameter[] -> System.Data.Objects.ObjectQuery<'T>

Public Function Where (predicate As String, ParamArray parameters As ObjectParameter()) As ObjectQuery(Of T)

Parameters

predicate: String

The filter predicate.

parameters: ObjectParameter[]

Zero or more parameters that are used in this method.

Returns

ObjectQuery<T>

A new ObjectQuery<T> instance that is equivalent to the original instance with WHERE applied.

Exceptions

ArgumentNullException

predicate is null.

-or-

parameters is null.

ArgumentException

The predicate is an empty string.

Examples

This example creates a new ObjectQuery<T> that contains results of the existing query filtered by the following criteria: "it.ProductID = 900".

int productID = 900;
using (AdventureWorksEntities context =
    new AdventureWorksEntities())
{
    string queryString =
        @"SELECT VALUE product FROM
            AdventureWorksEntities.Products AS product";

    ObjectQuery<Product> productQuery1 =
        new ObjectQuery<Product>(queryString,
            context, MergeOption.NoTracking);

    ObjectQuery<Product> productQuery2 =
        productQuery1.Where("it.ProductID = @productID");

    productQuery2.Parameters.Add(new ObjectParameter("productID", productID));

    // Iterate through the collection of Product items.
    foreach (Product result in productQuery2)
    {
        Console.WriteLine("Product Name: {0}; Product ID: {1}",
            result.Name, result.ProductID);
    }
}

Applies to