a layer between data base and application
-
Hello I want to ask you if anybody have an idea of a layer that can be added between the database and the application, I have heard about it, and they say that it helps in the diminution of the changes in the application when we change something in the database, and I heard also that this concept is in relation with classes. So please, if anybody had an idea, a book or a website that can helps me to study this concept gives it to me. Thanks a lot.
-
Hello I want to ask you if anybody have an idea of a layer that can be added between the database and the application, I have heard about it, and they say that it helps in the diminution of the changes in the application when we change something in the database, and I heard also that this concept is in relation with classes. So please, if anybody had an idea, a book or a website that can helps me to study this concept gives it to me. Thanks a lot.
I have a class that I have writen for comunicating with sql that makes it pretty simple. If you would like a copy send me an e-mail with your e-mail address and I will send it to you. Pablo www.aes4you.com
-
Hello I want to ask you if anybody have an idea of a layer that can be added between the database and the application, I have heard about it, and they say that it helps in the diminution of the changes in the application when we change something in the database, and I heard also that this concept is in relation with classes. So please, if anybody had an idea, a book or a website that can helps me to study this concept gives it to me. Thanks a lot.
You're referring to a Business Logic Layer (BLL) - the web is full of articles on this, by people better qualified than me, but in a nutshell a BLL sits between the UI and the data so that: The UI calls a BLL method (Such as: GetAllCustomers()) The BLL determines if the user is entitled to get this information, and if so calls some function of the Data Access Layer(DAL) (Such as: GetAllCustomers()) The DAL issues SQL commands to the database such as (SELECT * FROM Customers) The DAL returns the raw query results to the BLL The BLL returns the results of the the query to the UI, formatted in some useable format - maybe DataGrid rows or an array of strings. The UI Layer displays this information. It's a very powerful model, enabling you, as the developer, to de-couple the UI from the business rules and the data. In effect this means that your UI can change - be it WinForms, Web based (HTML, ASP etc), Avalon XAML forms without having to recode two major parts of your application.
-
You're referring to a Business Logic Layer (BLL) - the web is full of articles on this, by people better qualified than me, but in a nutshell a BLL sits between the UI and the data so that: The UI calls a BLL method (Such as: GetAllCustomers()) The BLL determines if the user is entitled to get this information, and if so calls some function of the Data Access Layer(DAL) (Such as: GetAllCustomers()) The DAL issues SQL commands to the database such as (SELECT * FROM Customers) The DAL returns the raw query results to the BLL The BLL returns the results of the the query to the UI, formatted in some useable format - maybe DataGrid rows or an array of strings. The UI Layer displays this information. It's a very powerful model, enabling you, as the developer, to de-couple the UI from the business rules and the data. In effect this means that your UI can change - be it WinForms, Web based (HTML, ASP etc), Avalon XAML forms without having to recode two major parts of your application.
that's what i need. thanks a lot , you made it. so 'll search the web now to know about the BLL and DAL.