Click here to Skip to main content
11,643,493 members (73,498 online)
Click here to Skip to main content
Add your own
alternative version

LINQ and Dynamic Predicate Construction at Runtime

, 13 Aug 2008 CPOL 119.5K 1.7K 83
Illustrating a multi-predicate injection pattern now possible with the new features of C# 3.0.
LINQDynamicPredicate_demo.zip
LINQDynamicSearchDemo
App_Data
Global.asax
NorthwindDB.dbml
NorthwindDB.dbml.layout
Properties
#pragma warning disable 1591
//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:2.0.50727.3053
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

namespace LINQDynamicSearchDemo
{
	using System.Data.Linq;
	using System.Data.Linq.Mapping;
	using System.Data;
	using System.Collections.Generic;
	using System.Reflection;
	using System.Linq;
	using System.Linq.Expressions;
	using System.ComponentModel;
	using System;
	
	
	[System.Data.Linq.Mapping.DatabaseAttribute(Name="Northwind")]
	public partial class NorthwindDBDataContext : System.Data.Linq.DataContext
	{
		
		private static System.Data.Linq.Mapping.MappingSource mappingSource = new AttributeMappingSource();
		
    #region Extensibility Method Definitions
    partial void OnCreated();
    partial void InsertEmployee(Employee instance);
    partial void UpdateEmployee(Employee instance);
    partial void DeleteEmployee(Employee instance);
    #endregion
		
		public NorthwindDBDataContext() : 
				base(global::System.Configuration.ConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString, mappingSource)
		{
			OnCreated();
		}
		
		public NorthwindDBDataContext(string connection) : 
				base(connection, mappingSource)
		{
			OnCreated();
		}
		
		public NorthwindDBDataContext(System.Data.IDbConnection connection) : 
				base(connection, mappingSource)
		{
			OnCreated();
		}
		
		public NorthwindDBDataContext(string connection, System.Data.Linq.Mapping.MappingSource mappingSource) : 
				base(connection, mappingSource)
		{
			OnCreated();
		}
		
		public NorthwindDBDataContext(System.Data.IDbConnection connection, System.Data.Linq.Mapping.MappingSource mappingSource) : 
				base(connection, mappingSource)
		{
			OnCreated();
		}
		
		public System.Data.Linq.Table<Employee> Employees
		{
			get
			{
				return this.GetTable<Employee>();
			}
		}
	}
	
	[Table(Name="dbo.Employees")]
	public partial class Employee : INotifyPropertyChanging, INotifyPropertyChanged
	{
		
		private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);
		
		private int _EmployeeID;
		
		private string _LastName;
		
		private string _FirstName;
		
		private string _Title;
		
		private string _TitleOfCourtesy;
		
		private System.Nullable<System.DateTime> _BirthDate;
		
		private System.Nullable<System.DateTime> _HireDate;
		
		private string _Address;
		
		private string _City;
		
		private string _Region;
		
		private string _PostalCode;
		
		private string _Country;
		
		private string _HomePhone;
		
		private string _Extension;
		
		private System.Data.Linq.Binary _Photo;
		
		private string _Notes;
		
		private System.Nullable<int> _ReportsTo;
		
		private string _PhotoPath;
		
		private EntitySet<Employee> _Employees;
		
		private EntityRef<Employee> _Employee1;
		
    #region Extensibility Method Definitions
    partial void OnLoaded();
    partial void OnValidate(System.Data.Linq.ChangeAction action);
    partial void OnCreated();
    partial void OnEmployeeIDChanging(int value);
    partial void OnEmployeeIDChanged();
    partial void OnLastNameChanging(string value);
    partial void OnLastNameChanged();
    partial void OnFirstNameChanging(string value);
    partial void OnFirstNameChanged();
    partial void OnTitleChanging(string value);
    partial void OnTitleChanged();
    partial void OnTitleOfCourtesyChanging(string value);
    partial void OnTitleOfCourtesyChanged();
    partial void OnBirthDateChanging(System.Nullable<System.DateTime> value);
    partial void OnBirthDateChanged();
    partial void OnHireDateChanging(System.Nullable<System.DateTime> value);
    partial void OnHireDateChanged();
    partial void OnAddressChanging(string value);
    partial void OnAddressChanged();
    partial void OnCityChanging(string value);
    partial void OnCityChanged();
    partial void OnRegionChanging(string value);
    partial void OnRegionChanged();
    partial void OnPostalCodeChanging(string value);
    partial void OnPostalCodeChanged();
    partial void OnCountryChanging(string value);
    partial void OnCountryChanged();
    partial void OnHomePhoneChanging(string value);
    partial void OnHomePhoneChanged();
    partial void OnExtensionChanging(string value);
    partial void OnExtensionChanged();
    partial void OnPhotoChanging(System.Data.Linq.Binary value);
    partial void OnPhotoChanged();
    partial void OnNotesChanging(string value);
    partial void OnNotesChanged();
    partial void OnReportsToChanging(System.Nullable<int> value);
    partial void OnReportsToChanged();
    partial void OnPhotoPathChanging(string value);
    partial void OnPhotoPathChanged();
    #endregion
		
		public Employee()
		{
			this._Employees = new EntitySet<Employee>(new Action<Employee>(this.attach_Employees), new Action<Employee>(this.detach_Employees));
			this._Employee1 = default(EntityRef<Employee>);
			OnCreated();
		}
		
		[Column(Storage="_EmployeeID", AutoSync=AutoSync.OnInsert, DbType="Int NOT NULL IDENTITY", IsPrimaryKey=true, IsDbGenerated=true)]
		public int EmployeeID
		{
			get
			{
				return this._EmployeeID;
			}
			set
			{
				if ((this._EmployeeID != value))
				{
					this.OnEmployeeIDChanging(value);
					this.SendPropertyChanging();
					this._EmployeeID = value;
					this.SendPropertyChanged("EmployeeID");
					this.OnEmployeeIDChanged();
				}
			}
		}
		
		[Column(Storage="_LastName", DbType="NVarChar(20) NOT NULL", CanBeNull=false)]
		public string LastName
		{
			get
			{
				return this._LastName;
			}
			set
			{
				if ((this._LastName != value))
				{
					this.OnLastNameChanging(value);
					this.SendPropertyChanging();
					this._LastName = value;
					this.SendPropertyChanged("LastName");
					this.OnLastNameChanged();
				}
			}
		}
		
		[Column(Storage="_FirstName", DbType="NVarChar(10) NOT NULL", CanBeNull=false)]
		public string FirstName
		{
			get
			{
				return this._FirstName;
			}
			set
			{
				if ((this._FirstName != value))
				{
					this.OnFirstNameChanging(value);
					this.SendPropertyChanging();
					this._FirstName = value;
					this.SendPropertyChanged("FirstName");
					this.OnFirstNameChanged();
				}
			}
		}
		
		[Column(Storage="_Title", DbType="NVarChar(30)")]
		public string Title
		{
			get
			{
				return this._Title;
			}
			set
			{
				if ((this._Title != value))
				{
					this.OnTitleChanging(value);
					this.SendPropertyChanging();
					this._Title = value;
					this.SendPropertyChanged("Title");
					this.OnTitleChanged();
				}
			}
		}
		
		[Column(Storage="_TitleOfCourtesy", DbType="NVarChar(25)")]
		public string TitleOfCourtesy
		{
			get
			{
				return this._TitleOfCourtesy;
			}
			set
			{
				if ((this._TitleOfCourtesy != value))
				{
					this.OnTitleOfCourtesyChanging(value);
					this.SendPropertyChanging();
					this._TitleOfCourtesy = value;
					this.SendPropertyChanged("TitleOfCourtesy");
					this.OnTitleOfCourtesyChanged();
				}
			}
		}
		
		[Column(Storage="_BirthDate", DbType="DateTime")]
		public System.Nullable<System.DateTime> BirthDate
		{
			get
			{
				return this._BirthDate;
			}
			set
			{
				if ((this._BirthDate != value))
				{
					this.OnBirthDateChanging(value);
					this.SendPropertyChanging();
					this._BirthDate = value;
					this.SendPropertyChanged("BirthDate");
					this.OnBirthDateChanged();
				}
			}
		}
		
		[Column(Storage="_HireDate", DbType="DateTime")]
		public System.Nullable<System.DateTime> HireDate
		{
			get
			{
				return this._HireDate;
			}
			set
			{
				if ((this._HireDate != value))
				{
					this.OnHireDateChanging(value);
					this.SendPropertyChanging();
					this._HireDate = value;
					this.SendPropertyChanged("HireDate");
					this.OnHireDateChanged();
				}
			}
		}
		
		[Column(Storage="_Address", DbType="NVarChar(60)")]
		public string Address
		{
			get
			{
				return this._Address;
			}
			set
			{
				if ((this._Address != value))
				{
					this.OnAddressChanging(value);
					this.SendPropertyChanging();
					this._Address = value;
					this.SendPropertyChanged("Address");
					this.OnAddressChanged();
				}
			}
		}
		
		[Column(Storage="_City", DbType="NVarChar(15)")]
		public string City
		{
			get
			{
				return this._City;
			}
			set
			{
				if ((this._City != value))
				{
					this.OnCityChanging(value);
					this.SendPropertyChanging();
					this._City = value;
					this.SendPropertyChanged("City");
					this.OnCityChanged();
				}
			}
		}
		
		[Column(Storage="_Region", DbType="NVarChar(15)")]
		public string Region
		{
			get
			{
				return this._Region;
			}
			set
			{
				if ((this._Region != value))
				{
					this.OnRegionChanging(value);
					this.SendPropertyChanging();
					this._Region = value;
					this.SendPropertyChanged("Region");
					this.OnRegionChanged();
				}
			}
		}
		
		[Column(Storage="_PostalCode", DbType="NVarChar(10)")]
		public string PostalCode
		{
			get
			{
				return this._PostalCode;
			}
			set
			{
				if ((this._PostalCode != value))
				{
					this.OnPostalCodeChanging(value);
					this.SendPropertyChanging();
					this._PostalCode = value;
					this.SendPropertyChanged("PostalCode");
					this.OnPostalCodeChanged();
				}
			}
		}
		
		[Column(Storage="_Country", DbType="NVarChar(15)")]
		public string Country
		{
			get
			{
				return this._Country;
			}
			set
			{
				if ((this._Country != value))
				{
					this.OnCountryChanging(value);
					this.SendPropertyChanging();
					this._Country = value;
					this.SendPropertyChanged("Country");
					this.OnCountryChanged();
				}
			}
		}
		
		[Column(Storage="_HomePhone", DbType="NVarChar(24)")]
		public string HomePhone
		{
			get
			{
				return this._HomePhone;
			}
			set
			{
				if ((this._HomePhone != value))
				{
					this.OnHomePhoneChanging(value);
					this.SendPropertyChanging();
					this._HomePhone = value;
					this.SendPropertyChanged("HomePhone");
					this.OnHomePhoneChanged();
				}
			}
		}
		
		[Column(Storage="_Extension", DbType="NVarChar(4)")]
		public string Extension
		{
			get
			{
				return this._Extension;
			}
			set
			{
				if ((this._Extension != value))
				{
					this.OnExtensionChanging(value);
					this.SendPropertyChanging();
					this._Extension = value;
					this.SendPropertyChanged("Extension");
					this.OnExtensionChanged();
				}
			}
		}
		
		[Column(Storage="_Photo", DbType="Image", UpdateCheck=UpdateCheck.Never)]
		public System.Data.Linq.Binary Photo
		{
			get
			{
				return this._Photo;
			}
			set
			{
				if ((this._Photo != value))
				{
					this.OnPhotoChanging(value);
					this.SendPropertyChanging();
					this._Photo = value;
					this.SendPropertyChanged("Photo");
					this.OnPhotoChanged();
				}
			}
		}
		
		[Column(Storage="_Notes", DbType="NText", UpdateCheck=UpdateCheck.Never)]
		public string Notes
		{
			get
			{
				return this._Notes;
			}
			set
			{
				if ((this._Notes != value))
				{
					this.OnNotesChanging(value);
					this.SendPropertyChanging();
					this._Notes = value;
					this.SendPropertyChanged("Notes");
					this.OnNotesChanged();
				}
			}
		}
		
		[Column(Storage="_ReportsTo", DbType="Int")]
		public System.Nullable<int> ReportsTo
		{
			get
			{
				return this._ReportsTo;
			}
			set
			{
				if ((this._ReportsTo != value))
				{
					if (this._Employee1.HasLoadedOrAssignedValue)
					{
						throw new System.Data.Linq.ForeignKeyReferenceAlreadyHasValueException();
					}
					this.OnReportsToChanging(value);
					this.SendPropertyChanging();
					this._ReportsTo = value;
					this.SendPropertyChanged("ReportsTo");
					this.OnReportsToChanged();
				}
			}
		}
		
		[Column(Storage="_PhotoPath", DbType="NVarChar(255)")]
		public string PhotoPath
		{
			get
			{
				return this._PhotoPath;
			}
			set
			{
				if ((this._PhotoPath != value))
				{
					this.OnPhotoPathChanging(value);
					this.SendPropertyChanging();
					this._PhotoPath = value;
					this.SendPropertyChanged("PhotoPath");
					this.OnPhotoPathChanged();
				}
			}
		}
		
		[Association(Name="Employee_Employee", Storage="_Employees", ThisKey="EmployeeID", OtherKey="ReportsTo")]
		public EntitySet<Employee> Employees
		{
			get
			{
				return this._Employees;
			}
			set
			{
				this._Employees.Assign(value);
			}
		}
		
		[Association(Name="Employee_Employee", Storage="_Employee1", ThisKey="ReportsTo", OtherKey="EmployeeID", IsForeignKey=true)]
		public Employee Employee1
		{
			get
			{
				return this._Employee1.Entity;
			}
			set
			{
				Employee previousValue = this._Employee1.Entity;
				if (((previousValue != value) 
							|| (this._Employee1.HasLoadedOrAssignedValue == false)))
				{
					this.SendPropertyChanging();
					if ((previousValue != null))
					{
						this._Employee1.Entity = null;
						previousValue.Employees.Remove(this);
					}
					this._Employee1.Entity = value;
					if ((value != null))
					{
						value.Employees.Add(this);
						this._ReportsTo = value.EmployeeID;
					}
					else
					{
						this._ReportsTo = default(Nullable<int>);
					}
					this.SendPropertyChanged("Employee1");
				}
			}
		}
		
		public event PropertyChangingEventHandler PropertyChanging;
		
		public event PropertyChangedEventHandler PropertyChanged;
		
		protected virtual void SendPropertyChanging()
		{
			if ((this.PropertyChanging != null))
			{
				this.PropertyChanging(this, emptyChangingEventArgs);
			}
		}
		
		protected virtual void SendPropertyChanged(String propertyName)
		{
			if ((this.PropertyChanged != null))
			{
				this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
			}
		}
		
		private void attach_Employees(Employee entity)
		{
			this.SendPropertyChanging();
			entity.Employee1 = this;
		}
		
		private void detach_Employees(Employee entity)
		{
			this.SendPropertyChanging();
			entity.Employee1 = null;
		}
	}
}
#pragma warning restore 1591

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Share

About the Author

dave.dolan
United States United States
Dave works all day, and stays up all night coding and reading, surfing the intertubes.

You may also be interested in...

| Advertise | Privacy | Terms of Use | Mobile
Web03 | 2.8.150731.1 | Last Updated 14 Aug 2008
Article Copyright 2008 by dave.dolan
Everything else Copyright © CodeProject, 1999-2015
Layout: fixed | fluid