Accessibility of Modifier in C#

		within assembly	outside assembly
	with inheritance	without inheritance	with inheritance	without inheritance
public	Yes	Yes	Yes	Yes
private	No	No	No	No
protected	Yes	No	yes	No
internal	yes	Yes	No	No
protected internal	Yes	Yes	Yes	No

         

Difference between Data Reader, Data Adapter, Dataset in C #

Data Reader 

Data Reader is used to read the data from Data Base in forward direction only Data Reader read the data in connected environment it will fetch the data very fast as comparison to Data set.

C# code 

Sqlconnection con=new Sqlconnection (“Data Source=.; integrated security=true; initial catalog=Master”)

{

con.open( );

Sqlcommand cmd=new Sqlcommand(“select * from emp”, con);

SqlDataReader dr= cmd.ExecuteReader ();

con.close();

}

Data Adapter

Data Adapter will work as a bridge between Data Reader and Data set, it is worked in disconnected architecture. Data Adapter is used to read the data from database and bind the data from data base.

Data set 

Data set work in the disconnected environment is the collection of Data tables and relations between tables .It is used to hold multiple tables with data. Data set also provides features like saving data as XML and loading XML data.

C# code 

Sqlconnection con=new Sqlconnection (“Data Source=.; integrated security=true; initial catalog=Master”)

{

con.open( );

Sqlcommand cmd=new Sqlcommand(“select * from emp”, con);

SqlDataAdapter sda = new SqlDataAdapter(cmd);

 DataSet ds = new DataSet();

 da.Fill(ds);

}

What is the difference between ADO and ADO.Net?

ADO	ADO.Net
Used connected data usage	Used disconnected data environment
Provided by record set	Provided by data set
Data is stored in binary format	Data is stored in XML format
It is COM based library	It is CLR based library
XML integration is not possible	XML integration is possible
ADO allows to create client-side cursors only	ADO.NET gives you the choice of either using client-side or server-side cursors
Join cannot be allow	Allow
Constraint cannot allow	Allow
Trigger cannot allow	Allow

Update multiple rows with different values SQL server

In this article I am going to explain how to update multiple row with different value by single Update Statement in SQL.

Here I am creating two table and by these two table I will update  employee table "salary column" value according to employee department with the help of "salary" table

CREATE TABLE Employee (                 EmpId INT identity(1, 1)                 ,NAME VARCHAR(50)                 ,Department VARCHAR(20)                 ,Salary MONEY                 )

create table salary ( Department VARCHAR(20) ,Salary MONEY )

Employee Table Data

Salary Table Data

Now I am writing a single update statement, which update employee salary according to department by the use of "salary" table.

UPDATE t1 SET t1.Salary = t2.Salary FROM Employee AS t1 INNER JOIN salary AS t2 ON t1.Department = t2.Department

After executing above  update query the employee table look like

What is difference between Dispose and finalize method in c#?

Dispose Method ()

-          Dispose method belong to the IDisposable interface

-          Dispose method will be used to free unmanaged resource like files, database connections etc.

-          To clear unmanaged resource we have to manually write the code to implement it.

-          It is faster method

-          Syntax of this method is void Dispose()

Finalize Method ()

-          Finalize method belong to the object class.

-          It is automatically raised by garbage collection mechanism when the object goes to scope.

-          It is slower method

-          Syntax for this method is protected virtual void Finalize()