Session.GetObjectsFromQuery(XPClassInfo, List<XPMemberInfo>, String, QueryParameterCollection) Method

Executes a SQL query and returns its result set as a collection of non-persistent objects.

Namespace: DevExpress.Xpo

Assembly: DevExpress.Xpo.v24.2.dll

Declaration

C#

public ICollection GetObjectsFromQuery(
    XPClassInfo classInfo,
    List<XPMemberInfo> members,
    string sql,
    QueryParameterCollection parameters
)

VB.NET

Public Function GetObjectsFromQuery(
    classInfo As XPClassInfo,
    members As List(Of XPMemberInfo),
    sql As String,
    parameters As QueryParameterCollection
) As ICollection

Parameters

Name	Type	Description
classInfo	XPClassInfo	An XPClassInfo object which contains the metadata information on a non-persistent class corresponding to the query’s result set. The class must be decorated with NonPersistentAttribute.
members	List<XPMemberInfo>	Specifies object members mapped to columns in the result set. The order of list elements should correspond to the order of result set columns.
sql	String	Specifies an SQL statement.
parameters	QueryParameterCollection	Specifies query parameter values.

Returns

Type	Description
ICollection	A collection of non-persistent classInfo objects instantiated with data obtained via the specified SQL query.

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(XPClassInfo, List<XPMemberInfo>, String, String[], QueryParameterCollection) method.

This method does the following:

• Executes the specified SQL query and obtains the query result.
• Creates objects using the specified classInfo 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 classInfo should represent a non-persistent class decorated with a NonPersistentAttribute.

Note

The GetObjectsFromQuery method throws an exception if the members array includes any of the following classInfo members:

• A property that is not defined within the classInfo object.
• 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.