ISqlModelMapper.TrackUpdate<TModel>(TModel model, Action<ISaveContext> afterSaveAction) Method

.NET Standard 2.x

Tracks a database table update operation and an Action<ISaveContext> object. The data that will be updated to the database table is cached in the TModel object. When ISqlModelMapper.SaveChanges method is called, a SQL UPDATE statement will be first generated using the data cached in the TModel object and the mapping information defined in TModel class, and then executed. After that, the Action<ISaveContext> object will be called.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

  public ISqlModelMapper TrackUpdate<TModel>(TModel model, Action<ISaveContext> afterSaveAction);

Type Parameters

TModel

The type of a model class.

Parameters

model TModel

The TModel object that contains the data you want to update to database.

afterSaveAction System.Action<SnapObjects.Data.ISaveContext>

An Action<ISaveContext> object that needs to be tracked.

Returns

SnapObjects.Data.ISqlModelMapper

Returns the current ISqlModelMapper object, which can be used for executing other methods.

Remarks

When instantiating the Action<ISaveContext> object, the generic parameter ISaveContext can be used for reading and writing the context which is used internally for saving data.

Examples

The following code example demonstrates how to use TrackUpdate<TModel>(TModel, Action<ISaveContext> ) method to track a database table update operation and an Action.

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

namespace Appeon.ApiDoc.ISqlModelMapperExamples
{
    public class TrackUpdateExample
    {
        private SchoolContext _context;

        public TrackUpdateExample(SchoolContext dataContext)
        {
            // Sets the data context.
            _context = dataContext;
        }

        public void Example2()
        {
            var mapper = _context.SqlModelMapper;

            // Gets the Engineering Department record (DepartmentID = 1) from 
            // the database.
            var department = mapper.LoadByKey<Department>(1).FirstOrDefault();

            mapper.TrackUpdate(department,
                (saveContext) =>
                {
                    Console.WriteLine("AfterSaveAction executed!");
                    Console.WriteLine("AffectedCount:{0}",
                        saveContext.LastDbResult.AffectedCount);
                });

            Console.WriteLine("The name is {0} (DepartmentID = 1).",
               department.Name);

            department.Name = "New Name";

            mapper.SaveChanges();

            // Gets data from the database (DepartmentID = 1).
            department = mapper.LoadByKey<Department>(1).FirstOrDefault();
            Console.WriteLine("The name is \"{0}\" for the department when DepartmentID is 1.",
               department.Name);

            /*The code example produces the following output:
            
            The name is Engineering (DepartmentID = 1).
            AfterSaveAction executed!
            AffectedCount:1
            The name is New Name (DepartmentID = 1).
            */
        }
    }
}

Example Refer To

Model Class: Department

Applies to

.NET Standard

2.x