ExecuteScalar(),ExecuteNonquery(),ExecuteReader()

There are basically three methods provided by ADO.Net to work with database in asp.net.

Thease are as follows


1-ExecuteScalar()-
- The return type of ExecuteScalar() method is Object type.

- It will used to return a single value.

2-ExecuteNonquery()-
- The return type of ExecuteNonquery() method is Integer type.

- It will used in case of insert,update,delete statement.


3-ExecuteReader()-
- The return type of ExecuteReader() method is sqldatareader type.

- It will return multiple values i.e select statement.

You can also check a very good article on Difference between Abstract class and Interface.