Programming using Layered Dot Net Architecture
how to write efficient code and how to represent the information which take advantage of layered design of .net framework. You must also now aware about how you can write code efficiently and improve performance of application and avoids errors due to poor coding style.
Programming using Layered Dot Net Architecture
Note: To make you understand the concept i have started with example
OK, so Lets Start by understanding need of writing a layered programming.
Well for this article I will focus on ADO.net Programming structure, but you can implement with other programming structures too...
Ok, so +ve points for layered programming with ADO.net
i) Opening of connection for a short time and Closing it as soon as database task is completed, it thus help in improving performance of application.
ii) Better usage of Error-Handling, to make sure that connection is closed even if the exception occurs.
iii) Follow Stateless design, taking all needed information as parameter and return all the data through return value. It helps in load balancing and it would be easy while implementing web-service.
iv) Storing connection string in app.config file allow us to made a single change, to change a connection string. It helps in connection pooling.
Now lets understand how to undergo the procedure to achieve above advantages...
ADO.net Programming Style consist of Layered design which describes as bellow:1. User Interface Layer
User Interface consist of Forms which are been designed to interact with User.
2. Stub for Accessing Database Layer
Stub for accessing database layer is been prepared by creating classes which contains a specific details related to access data and task such as adding, editing and deleting functionality..
Note: Connection string is retrieved from
<appSettings>
<add key="connStr" value="data source=(local);Initial Catalog=Northwind;Integrated Security=SSPI">
</add>
</appSettings>
Stub consist of two class files:
2.1) A data details class and
2.2) A database utility class.
Here I have taken Example of filling basic employeed details
2.1) Data Details Class: It consist of details of record which is manipulated.
public class EmpDetails
{
/* Declaring Property for each field. */
private int employeeId;
public int EmployeeId
{
get{return employeeId;}
set{employeeId = value;}
}
private string firstName;
public string FirstName
{
get{return firstName;}
set{firstName = value;}
}
private string lastName;
public string LastName
{
get{return lastName;}
set{lastName = value;}
}
/* Constructor definition */
public EmpDetails(int employeeId,
string firstName,string lastName)
{
this.employeeId = employeeId;
this.firstName = firstName;
this.lastName = lastName;
}
}
2.2) Database Utility Class: It consist of different data manipulation operation (such as add, delete, update, select) which is performed to the actual database.
public class EmpDB
{
string connStr;
/* Retrieving Connection String in Constructor*/
public EmpDB()
{
connStr = ConfigurationSettings.AppSettings["connStr"];
}
/* Insertion of employee details*/
public int InsertEmployee(EmpDetails emp)
{
// Opening Connection
SqlConnection conn = new SqlConnection(connStr);
// Creating Command
SqlCommand cmd = conn.CreateCommand();
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "procInsertEmployee";
// Adding required parameter
cmd.Parameters.Add(new SqlParameter("@EmployeeId",SqlDbType.Int));
cmd.Parameters["@EmployeeId"].Direction = ParameterDirection.Output;
cmd.Parameters.Add(new SqlParameter("@FirstName",SqlDbType.NVarChar,20));
cmd.Parameters["@FirstName"].Value = emp.FirstName;
cmd.Parameters.Add(new SqlParameter("@LastName",SqlDbType.NVarChar,20));
cmd.Parameters["@LastName"].Value = emp.LastName;
try
{
conn.Open();
// Executing Command and retrieving result.
int RecordsAffected = cmd.ExecuteNonQuery();
int EmpId;
if(RecordsAffected != 0)
EmpId = (int)cmd.Parameters["@EmployeeId"].Value;
else
EmpId = -1;
return EmpId;
}
catch(SqlException ex)
{
throw new ApplicationException("Data Error");
}
finally
{
// Ensuring that Connection is closed even if exception occurs.
conn.Close();
}
}
// Similarly Perform different database opperation
// Check out "EmpDB.cs" for demo code.
public int UpdateEmployee(EmpDetails emp)
{...}
public int DeleteEmployee(int EmployeeId)
{...}
public EmpDetails GetEmployee(int EmployeeId)
{...}
public EmpDetails[] GetAllEmployee()
{...}
} 3. Database Layer
Database layer is server where MS SQL Server is installed, or where the database is actually stored. This code design is independent of database layer.
Conclusion
Thus by end of this article, you have understand how to write efficient code and how to represent the information which take advantage of layered design of .net framework. You must also now aware about how you can write code efficiently and improve performance of application and avoids errors due to poor coding style.
Hope to hear your useful comments so that together we can make programming easy and efficient.