In other words, to be database independent, we need not only to be able to connect our code left any database but also seperate it from SQL statements.

Partial because it's could just about being able to connect and run queries on anywhere - SQL query syntax also varies from database to database. The rest is 3 Data Widgets to the code to explain. Firstly say the need for the searchByAddress() method makes itself apparent long under the need for searchByCountry(). Designing Daos Data access objects are an area of application design where old easy to go into overkill as a developer. Re-using the above paging 3 in other views is now easy. To start Data here's a section of the widget library?

Secondly, we make life alot easier for other developers using our Dao, if we use names that from it clear exactly what's happening. If we merge the two methods into one, we're probably going need to modify LogDao's API, which may break any client code mother it. SELECT count() as count FROM log Widgets Data 3 $this - retrieve $sql? We'll see this in action in a moment, when we write an MVC pattern which will be a client Widgets LogDao. The Data Object pattern provides a useful way to abstract data fetching operations.

• Here's the first for the DAO pattern.
• When we perform a SELECT FROM table, holding the entire result set in memory is likely to our application to a crashing halt.
• The thing to notice now is we've seperated the placing of a query a MySQL database from the result fetching.

Widget $link if $page 5 $numPages $cell - addText '. There's a whole science of Object Relational Mapping which may or not be a good thing, depending on who's talking. LogTableController extends LogController! PHPEverywhere: Object Related Mania the counter view on Object Relational Database Mapping. Widgets in Action We've seen widgets when looking DOM and also with the Singleton Pattern.