Session.GetObjectsFromQuery<T>(LoadDataMemberOrderItem[], String, QueryParameterCollection) Method

Executes a SQL query and returns its result set as a collection of objects of a non-persistent type specified by the generic type parameter.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v24.1.dll

NuGet Packages: DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap, DevExpress.Xpo

NuGet Package: DevExpress.Xpo

Declaration

C#

public ICollection<T> GetObjectsFromQuery<T>(
    LoadDataMemberOrderItem[] members,
    string sql,
    QueryParameterCollection parameters
)

VB.NET

Public Function GetObjectsFromQuery(Of T)(
    members As LoadDataMemberOrderItem(),
    sql As String,
    parameters As QueryParameterCollection
) As ICollection(Of T)

Parameters

Name	Type	Description
members	LoadDataMemberOrderItem[]	An array of LoadDataMemberOrderItem objects which provide mapping information for object members and the query’s result set columns.
sql	String	Specifies an SQL statement.
parameters	QueryParameterCollection	Specifies query parameter values.

Type Parameters

Name	Description
T	The type of objects returned by the method. A class that implements this type sould be decorated with NonPersistentAttribute.

Returns

Type	Description
ICollection<T>	A collection of non-persistent objects of the specified type.

Remarks

Use QueryParameterCollection to pass strongly-typed parameters. See examples here: Always Encrypted (SQL Server only).

The connection provider automatically generates sequential parameter names (p0, p1, p2 …). To specify custom parameter names, use the overloaded GetObjectsFromQuery<T>(LoadDataMemberOrderItem[], String, String[], QueryParameterCollection) method.

This method does the following:

• Executes the specified SQL query and obtains the query result.
• Creates objects of the specified type and populates their properties with the resulting set’s data. The members parameter specifies the mapping between columns in the resulting set and object properties. Note that the GetObjectsFromQuery<T> method’s generic type parameter should specify a non-persistent class decorated with a NonPersistentAttribute.
• Populates a collection with these objects.

Note

The GetObjectsFromQuery<T> method throws an exception if the members list includes any of the following object members:

• A property that is not defined within the T type.
• A struct type member.
• A reference to a class with a struct type member.
• A collection used in object relations.

To learn more about executing SQL statements in XPO, refer to Direct SQL Queries.

Note

The GetObjectsFromQuery method sends statements directly, so the correct statement syntax and parameter names format depends on a particular database server.