ISqlModelMapper.LoadAllAsync<TModel>(CancellationToken cancellationToken) Method

.NET Standard 2.x

Asynchronously retrieves data from the database according to the SQL query (without the Where clause) defined by the primary table in a TModel class.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

public Task<ILoadable<TModel>> LoadAllAsync<TModel>(CancellationToken cancellationToken)

Type Parameters

TModel

The type of a model class.

Parameters

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.

Remarks

If the SQL query defined in TModel makes query from multiple tables, this method only retrieves and loads data from the primary table.

If TModel has properties that apply attributes such as SqlCompute, NotMapped etc., LoadAll and LoadByKey cannot load data of such properties. In such case, use Load instead of LoadAll and LoadByKey.

Examples

The following code example demonstrates how to load departments asynchronously without the Where clause according to a model class. It uses a CancellationTokenSource type parameter to make this operation cancelable.

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

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

        public async Task<int> Example2(CancellationTokenSource cts)
        {
            var mapper = _context.SqlModelMapper;
            
            int count = 0;
            
            try 
            {
                // Asynchronously lLoads the department of Engineering using LoadAll
                // It retrieves all records from Department table. 
                // If a task has been cancelled, the call to the ISqlModelMapper.LoadAsync 
                // method throws an OperationCanceledException.
                count = (await mapper.LoadAllAsync<DepartmentByName>(cts.Token)).ToList().Count;
                
                Console.WriteLine("Count (LoadAllAsync): {0}", count);
            }
            catch (OperationCanceledException e)
            {
                // The operation was cancelled before completion.
                Console.WriteLine(e.Message);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally
            {
                cts.Dispose();
            }
            
            return count;
            
            /* The code produces the following output:
            
                A task was canceled.
            */
        }
    }
}

Example Refer To

Model Class: DepartmentByName

Applies to

.NET Standard

2.x