{"id":15177,"date":"2015-06-02T05:01:15","date_gmt":"2015-06-01T19:01:15","guid":{"rendered":"http:\/\/www.rjmprogramming.com.au\/ITblog\/?p=15177"},"modified":"2015-06-01T13:27:23","modified_gmt":"2015-06-01T03:27:23","slug":"php-object-interface-primer-tutorial","status":"publish","type":"post","link":"https:\/\/www.rjmprogramming.com.au\/ITblog\/php-object-interface-primer-tutorial\/","title":{"rendered":"PHP Object Interface Primer Tutorial"},"content":{"rendered":"
\"PostgreSQL<\/a>

PHP Object Interface Primer Tutorial<\/p><\/div>\n

Today we are going to show a PHP example of object “interface”, and we like the excerpt from the useful link<\/a> below, which discusses the same “database” interface idea as we are going to tackle today …<\/p>\n

\nThe point is – the INTERFACE describes the methods that we need to access our database. It does NOT describe in any way HOW we achieve that. That’s what the IMPLEMENTing class does. We can IMPLEMENT this interface as many times as we need in as many different ways as we need. We can then switch between implementations of the interface without impact to our code because the interface defines how we will use it regardless of how it actually works.\n<\/p><\/blockquote>\n

… in that today, on our local MAMP<\/a> web server, we imagine a web application able to toggle between two different database arrangements for …<\/p>\n

    \n
  1. PostgreSQL<\/li>\n
  2. MySql<\/li>\n<\/ol>\n

    … to present some “films” (table) data, as we did a few days ago when we just did a PostgreSQL version with PostgreSQL PHP Tutorial<\/a>.<\/p>\n

    So, as you can tell with our PHP source code filminterface.php<\/a> where we go …<\/p>\n


    \ninterface Database {
    \n function listFilms();
    \n function addFilm($code, $title, $did, $date_prod, $kind, $len);
    \n function removeFilm($code);
    \n function amendFilm($code, $title, $did, $date_prod, $kind, $len);
    \n}
    \n<\/code><\/p>\n

    … with our “Database” interface class, that this interface class shows what functionality occurs in common for classes that “interface” to it via …<\/p>\n


    \nclass MySqlDatabase implements Database {
    \n\/\/ ...
    \n}
    \nclass PostgreSQLDatabase implements Database {
    \n\/\/ ...
    \n}
    \n<\/code><\/p>\n

    Please feel free to examine the code and try a scenario yourself in a Mac OS X MAMP Apache\/PHP\/MySql (and add your own PostgreSQL (how to install is discussed at PostgreSQL Primer Tutorial<\/a> way below)) environment.<\/p>\n

    \n

    Previous relevant PostgreSQL PHP Tutorial<\/a> is shown below.<\/p>\n

    \"PostgreSQL<\/a>

    PostgreSQL PHP Tutorial<\/p><\/div>\n

    Some time ago we talked about the PostgreSQL database, and showed you some command line (installation and) usage via a MacBook Pro Terminal application’s (bash environment) command line.<\/p>\n

    So that showed a bit of SQL for PostgreSQL and you can see it is a lot like other database SQL, and am not about to tell you otherwise today.<\/p>\n

    The only SQL part that may not be transportable to other database SQL today, is the use of the PostgreSQL “to_date()”<\/a> function, but the lesson is that so much relational database coalesces with the SQL (DML<\/a>) for …<\/p>\n