ISqlModelMapper.LoadAsync<TModel>(object[] parameters, CancellationToken cancellationToken) Method

.NET Standard 2.x

Asynchronously retrieves data according to the SQL query defined in a TModel class.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

public Task<ILoadable<TModel>> LoadAsync<TModel>(object[] parameters, CancellationToken cancellationToken)

Type Parameters

TModel

The type of a model class.

Parameters

parameters System.Object[]

One or more values that you want to use as retrieval arguments in the SQL SELECT statement defined in TModel.

cancellationToken CancellationToken

A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Task<ILoadable<TModel>>

Returns a task that represents the asynchronous operation.

Examples

The following code example demonstrates how to load departments asynchronously according to a model class. It uses a CancellationTokenSource type parameter to make this operation cancelable.

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Appeon.ApiDoc.Models.School;

namespace Appeon.ApiDoc.ISqlModelMapperExamples
{
    public class LoadAsyncExample
    {
        private readonly SchoolContext _context;
        
        public LoadAsyncExample(SchoolContext dataContext)
        {
            // Sets the data context.
            _context = dataContext;
        }

        public async Task<DepartmentByName> Example2(CancellationTokenSource cts)
        {
            var mapper = _context.SqlModelMapper;
            
            DepartmentByName depts = null;
            
            try
            {
                // Asynchronously loads the department of Engineering.
                // If a task has been cancelled, the call to the ISqlModelMapper.LoadAsync 
                // method throws an OperationCanceledException.
                depts = (await mapper.LoadAsync<DepartmentByName>(
                    new object[] { "Engineering" } , cts.Token)).FirstOrDefault();
                    
                Console.WriteLine();
                Console.WriteLine("The department of Engineering:");
                Console.WriteLine("Department ID is {0}", depts.DepartmentID);
                Console.WriteLine("Name is {0}", depts.Name);
                Console.WriteLine("Budget is {0}", depts.Budget.ToString("N0"));
            }
            catch (OperationCanceledException e)
            {
                // The operation was cancelled before completion.
                Console.WriteLine(e.Message);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally
            {
                cts.Dispose();
            }
            
            return depts;
            
            /* This code produces the following output:
            
                A task was canceled.
            */
        }
    }
}

Example Refer To

Model Classes: Department DepartmentByName

Applies to

.NET Standard

2.x