Session.GetObjectsFromQueryAsync(XPClassInfo, List<XPMemberInfo>, String, String[], Object[], CancellationToken) Method
Asynchronously 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
NuGet Package: DevExpress.Xpo
#Declaration
public Task<ICollection> GetObjectsFromQueryAsync(
XPClassInfo classInfo,
List<XPMemberInfo> members,
string sql,
string[] parameterNames,
object[] parameterValues,
CancellationToken cancellationToken = default(CancellationToken)
)
#Parameters
Name | Type | Description |
---|---|---|
class |
XPClass |
An XPClass |
members | List<XPMember |
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. |
parameter |
String[] | Specifies parameter names. |
parameter |
Object[] | An array of objects specifying parameters to pass to the database server along with the query. |
#Optional Parameters
Name | Type | Default | Description |
---|---|---|---|
cancellation |
Cancellation |
null | A Cancellation |
#Returns
Type | Description |
---|---|
Task<ICollection> | A Task |
#Remarks
string sql = "select (FirstName + ' ' + LastName) as Name, City, Country from Employees where City = @city";
XPClassInfo classInfo = session.GetClassInfo<EmployeeModel>();
List<XPMemberInfo> members = new List<XPMemberInfo>() {
classInfo.GetMember(nameof(EmployeeModel.Name)),
classInfo.GetMember(nameof(EmployeeModel.City)),
classInfo.GetMember(nameof(EmployeeModel.Country))
};
ICollection queryResultData = await session.GetObjectsFromQueryAsync(classInfo, members, sql, new[] { "city" }, new[] { "London" });
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 Get
- A property that is not defined within the class
Info 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 Get