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

Definition

Limits the query to results that match specified filtering criteria.

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

Parameters

predicate
String

The filter predicate.

parameters
ObjectParameter[]

Zero or more parameters that are used in this method.

Returns

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

Exceptions

predicate is null.

-or-

parameters is null.

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

Produkt Versjoner
.NET Framework 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

See also