IEmbeddedLoadable.Include(Expression<Func<TModel, object>> property, bool cascade = false) Method

.NET Standard 2.x

Loads data for the specified embedded property in TModel for all rows.

If the ModelEmbedded attribute is applied in the property, the property will use the SQL query (defined in the detail model class specified by the ModelType property of the ModelEmbedded attribute) to retrieve data from database. The cascade parameter can be used to decide whether to retrieve data for the embedded properties in the detail model or the granddetail model.

Namespace: SnapObjects.Data

Assembly: SnapObjects.Data.dll

Syntax

  IEmbeddedLoadable<TModel> Include(Expression<Func<TModel, object>> property, bool cascade = false);

Parameters

property System.Linq.Expressions.Expression

An embedded property of TModel class.

This property is specified by an expression.

cascade System.Boolean

Only when the ModelEmbedded attribute is applied in the property, the cascade parameter can be used to decide whether to retrieve data for the embedded properties in the detail model or the granddetail model. See master-detail-granddetail for more info.

The default value is false.

Returns

SnapObjects.Data.IEmbeddedLoadable<TModel>

Returns the current IEmbeddedLoadable<TModel> object whose methods can be used to further obtain the data result set or perform data operations such as embedded queries.

Remarks

The IEmbeddedLoadable.Include method can be used to load the data for the specified embedded properties rather than loading data for all properties. This can greatly improve the data retrieval efficiency.

Examples

The following code example demonstrates how to load courses for a department.

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

namespace Appeon.ApiDoc.IEmbeddedLoadableExamples
{
    public class IncludeExample
    {
        private SchoolContext _context;

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

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

            // Loads the information for the Engineering department but
            // it does not load courses here.
            var dept = mapper.Load<DepartmentInfo>()
                            .ToList()
                            .Find(o => o.Name == "Engineering");
            Console.WriteLine("Department: {0}",
                dept.Name);

            // Loads courses that belong to the Engineering department.
            mapper.LoadEmbedded(dept).Include(o => o.Courses);

            Console.WriteLine();
            Console.WriteLine("Courses:");
            foreach (CourseInfo course in dept.Courses)
            {
                Console.WriteLine(course.Title);
            }

            /*The code produces the following output:
            
            Department: Engineering

            Courses:
            Chemistry
            Physics
            */
        }
    }
}

Example Refer To

Model Classes: DepartmentInfo CourseInfo

Applies to

.NET Standard

2.x