Skip to main content

What is 3-tier Architecture

The 3-tier Architecture is all about separating the Business Logic from the Application and Data Storage. i.e., Database (in general). It is popularly called as MVC (Model-View-Controller) Model. User will interact with View part in the application. This will be controlled by Controller and Model layers.

Whenever user performs something, that will call some action handler in the Code behind and calls a functions in the Controller. In Object Oriented approach, Model consists of Business objects. Depending on the situation, some business object will be created and that will be used to store and retrieve data from the Database.

This separation is needed in real time application,
Because the change in one layer should not effect the other layer's functionality.

For Ex. Change in the Database from SQL server to Oracle is nowhere related to user. So he/she should not know these details while interacting with the system.
Labels:

Comments

Post a Comment

Popular posts from this blog

Solution Array for List in WCF

Here is another common problem encounters with WCF Service in initial days. Suppose there is a method which returns a List of Objects the proxy will be generated as method which returns an array of objects. Reason: This problem is due to the default interpretation of collections. While generating proxy for the service all the collections are by default interpreted as arrays. That is why all the lists will be converted to arrays. Solution: If you are generating proxy by adding service reference from visual studio directly, there will be a 'advanced' button. Click that button and select the System.Generic.List as your Collection. This will resolve the problem. If you are generating proxy with svcutil here is the command to do the job. svcutil.exe http://ServerName/ServiceName/Servic.svc?wsdl /collectionType:System.Collections.Generic.List`1 or in short svcutil http://ServerName/ServiceName/Servic.svc?wsdl /ct:System.Collections.Generic.List`1 for more information go through this ...
1 comment
Read more

Linq: Query for multiple join conditions in Linq to SQL

This is common to join a table with another on multiple conditions, Like Select * from Customer c Join Invoice i on c.CustomerID = i.CustomerID and c.CustomerTypeID = i.CustomerTypeID I need to write a Linq to SQL query for the same scenario. But the syntax for this query is a bit different to expect. The Linq query is as follows: From c in DataContext .Customers Join i in DataContext .Invoices on new { c.CustomerID, c.CustomerTypeID } equals new { i.CustomerID, i.CustomerTypeID } *DataContext in the above query should be replaced with actual datacontext name.
3 comments
Read more

Troubleshoot WCF service returning object with null fields

When you are working with WCF service for the first time, generally you will get this error for some reason. Here is the description of the error: WebServiceReference . ServiceClient client = new WebServiceReference . ServiceClient (); WebServiceReference . ImplementationRequest req = new WebServiceReference . ImplementationRequest (); req = client.GetRequest(); Here the Method GetRequest will return an object of ImplementationRequest. Everything will run without any error but the req object will contain all null fields/ majority null fields. Solution: Those nulls are due to error in generating the proxy for the Data Contract defined by the service. Verify that [DataMember] attribute tag is given for all the data fields and [DataContract] for the Class. If those attributes are missing, the object will be generated with null values. If all fields have the tags but the issue is not resolved, then the service reference should be re-added and the proxy should be re-generated. Then t...
1 comment
Read more