How to Copy Properties form one object to another in linq

We can copy properties from one object to another by writing extention method to linq


public static class LinqExtensions
        public static void CopyPropertiesTo<T>(this T source, T dest)
            var plist = from prop in typeof(T).GetProperties() where prop.CanRead && prop.CanWrite select prop;

            foreach (PropertyInfo prop in plist)
                prop.SetValue(dest, prop.GetValue(source, null), null);

Complete Project On Entity Framework and crystal Reports

Hi Guys… On sep-21st-2012 My site completes 1 year so that i am providing free downlod of a project entitled as HOUSE FINANCE APPLICATION

This project includes

3.Crystal Reports

4.linq to entities

5.Jquery Ajax

7.Sql & Tsql


How to apply distinct Method on particular column in LINQ

Sometimes we need to select two or more columns based on one column distinct
in this situation if we have one primary column and one columns allows duplicates so now we want to read these two columns based on column which allow duplicates… in this situation if we apply Distinct method it will takes records based on primary key column, it won’t read based on other column…
To do that….follows these steps…

first create one method for DistinctBy

public static IEnumerable<TSource> DistinctBy<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> selector)
            var set = new HashSet<TKey>();
            return source.Where(element => set.Add(selector(element)));

and use this method to do Distinct based on Particular column…

var x = (from n in context.tblEmployees.Where(i => i.EMPLOYEE_ID == EmployeeId) select n).DistinctBy(i => i.EmployeeName).ToList();



LINQ: Sequence Contains No Elements:First()

LINQ: Sequence Contains No Elements:

The InvalidOperationException:Sequence contains no lelments exception will occur whenever we will try to retrive data from table in database doesn’t contain no elements… so whenever we are trying to get data it does not match our query, this error will occur.

 What is First() in Linq:

Whenever we want to select first record only from list of records we will use this first() method as follows

Var x = (from n in Contextorentity.TableName select n).first();

If we want to select last record only from list of records we will use Last() method as follows

Var x = (from n in Contextorentity.TableName select n).first();

Without where Condition:

 var x = (from n in Contextorentity.TableName select n).first();

if the above select query contains no records in it it will return error like sequence contain no elements

with where condition:

if we are using any where condition in our query as follows

var x = (from n in Contextorentity.Employee where n.EmpId == 100  select n).first();

if no record matches with this query it returns error because the first method should select single record from list only, so if no list founds it will returns error.


We have solution for this error in linq only that is,

Instead of using First() method we can use FirstOrDefault() method.

What is FirstOrDefault() Method:

Firstordefault() method will also select single record from list of records, if no records found it will returns null value, so error won’t come…



………………..Happy Coding………………….