ISqlModelMapper.TrackDelete<TModel>(TModel model) Method

.NET Standard 2.x

Tracks a database table delete operation. The data that will be deleted from the database table is cached in the TModel object. When ISqlModelMapper.SaveChanges method is called, a SQL DELETE statement will be first generated using the data cached in the TModel object and the mapping information defined in TModel class, and then executed.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

  public ISqlModelMapper TrackDelete<TModel>(TModel model);

Type Parameters

TModel

The type of a model class.

Parameters

model TModel

The TModel instance that corresponds to the database record.

Returns

SnapObjects.Data.ISqlModelMapper

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

Examples

The following code example demonstrates how to delete a student record.

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

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

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

        public void Example1()
        {
            var mapper = _context.SqlModelMapper;

            // Creates a new student.
            var newStudent = new Person()
            {
                LastName = "Senior",
                FirstName = "Letitia",
                EnrollmentDate = new DateTime(2019, 1, 1),
                Discriminator = "Student"
            };

            // Tracks the new student and saves changes to the database.
            var dbResult = mapper.TrackCreate(newStudent)
                                 .SaveChanges();

            Console.WriteLine("{0} record has been inserted into the database.",
                dbResult.InsertedCount);

            // Deletes the student from the database.
            dbResult = mapper.TrackDelete(newStudent).SaveChanges();

            Console.WriteLine("{0} record has been deleted from the database.",
                dbResult.DeletedCount);

            /* The code produces the following output:
            
            1 record has been inserted into the database.
            1 record has been deleted from the database.
            */
        }
    }
}

Example Refer To

Model Class: Person

Applies to

.NET Standard

2.x