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DataContext.ExecuteQuery<TResult> Method (String, Object[])

Executes SQL queries directly on the database and returns objects.

Namespace:  System.Data.Linq
Assembly:  System.Data.Linq (in System.Data.Linq.dll)

public IEnumerable<TResult> ExecuteQuery<TResult>(
	string query,
	params Object[] parameters
)

Type Parameters

TResult

The type of the elements in the returned collection.

Parameters

query
Type: System.String
The SQL query to be executed.
parameters
Type: System.Object[]
The array of parameters to be passed to the command. Note the following behavior:
If the number of objects in the array is less than the highest number identified in the command string, an exception is thrown.
If the array contains objects that are not referenced in the command string, no exception is thrown.
If a parameter is null, it is converted to DBNull.Value.

Return Value

Type: System.Collections.Generic.IEnumerable<TResult>
A collection of objects returned by the query.

This method is a pass-through mechanism for cases where LINQ to SQL does not provide for a particular scenario.

The algorithm for matching columns in the result of the query to fields and properties in the object works as follows:

  • If a field or property is mapped to a particular column name, that column name is expected in the resultset.

  • If a field or property is not mapped, a column with the same name as the field or property is expected in the resultset.

  • The comparison is performed by first looking for a case-sensitive match. If such a match is not found, a subsequent search occurs for a case-insensitive match.

  • The query must return all the tracked fields and properties of the object (apart from those subject to deferred loading) when all the following are true:

    • If <T> is an entity explicitly tracked by the DataContext.

    • ObjectTrackingEnabled is true.

    • The entity has a primary key.

    Otherwise an exception is thrown.

  • In all other cases, the query can retrieve just a subset of the tracked fields and properties for the object.

The following C# snippet shows one use for this method:

var customers = db.ExecuteQuery<Customer>(@"SELECT CustomerID, CompanyName, ContactName, ContactTitle, 
   Address, City, Region, PostalCode, Country, Phone, Fax
   FROM   dbo.Customers
   WHERE  City = {0}", "London");

foreach (Customer c in customers)
   Console.WriteLine(c.ContactName);

In Visual Basic

Dim customers = db.ExecuteQuery(Of Customer)("SELECT CustomerID, _    CompanyName, ContactName, ContactTitle, _
   Address, City, Region, PostalCode, Country, Phone, Fax _
   FROM dbo.Customers _
WHERE City = {0}", "London")

For Each c As Customer In customers
    Console.WriteLine(c.ContactName)
Next

.NET Framework

Supported in: 4, 3.5

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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