Trouble grasping OOP concepts

[Venom Rush]

Hi all

I'm learning OOP and I'm having a bit of trouble grasping the concepts. I'm trying to code a class that will connect to a database and have a function that will insert data into a table no matter how complex the insert is. For instance:

Insert 1:
INSERT INTO animals (animal type, size, age) VALUES ($animal_type, $size, $age)

Insert 2:
INSERT INTO food (type, calories) VALUES ($type, $calories)

Basically I'm not sure how to create a function to do this or if I should make an abstract class or create an interface.

P.S. I have more than one table each with differing amounts of columns.

[nav33n]

Hi there! I am not sure about the idea of an abstract class or an interface. Here is a simple example of a class with 3 functions, getConnection, closeConnection and insertToTable. getConnection is to connect to the database and closeConnection to close(!). The function insertToTable takes 1 parameter, that is an array. You can pass as many values you want through the array and insert relative values to the table.

<?php
class Database {
	private $db_connection;
	public function getConnection(){
		$this->db_connection=mysql_connect("localhost","root","passw");
		mysql_select_db("databasename");
		if(!$this->db_connection) {
			die('Could not connect'.mysql_error());
		} else {
			return $this->db_connection;
		} 
	}
	public function closeConnection() {
		mysql_close($this->db_connection);
	}
	public function insertToTable($data){
		 $animal_type = $data['animal_type'];
		 $animal_age = $data['animal_age'];
		 /* and all the other data */
		 $insert_to_table1 = "insert into animal (type) values ('$animal_type');
		 mysql_query($insert_to_table1);
		 $insert_to_table2 = "insert into animal_age (age) values ('$animal_age');
		 mysql_query($insert_to_table2);
	}
}	
$obj_Connection = new Database();
$obj_Connection->getConnection();
$data = array();
$data['animal_type'] = "dog";
$data['animal_age'] = 12;
$obj_Connection->insertToTable($data);
$obj_Connection->closeConnection();
?>

Cheers!

[Venom Rush]

Hi there! I am not sure about the idea of an abstract class or an interface. Here is a simple example of a class with 3 functions, getConnection, closeConnection and insertToTable. getConnection is to connect to the database and closeConnection to close(!). The function insertToTable takes 1 parameter, that is an array. You can pass as many values you want through the array and insert relative values to the table.

<?php
class Database {
	private $db_connection;
	public function getConnection(){
		$this->db_connection=mysql_connect("localhost","root","passw");
		mysql_select_db("databasename");
		if(!$this->db_connection) {
			die('Could not connect'.mysql_error());
		} else {
			return $this->db_connection;
		} 
	}
	public function closeConnection() {
		mysql_close($this->db_connection);
	}
	public function insertToTable($data){
		 $animal_type = $data['animal_type'];
		 $animal_age = $data['animal_age'];
		 /* and all the other data */
		 $insert_to_table1 = "insert into animal (type) values ('$animal_type');
		 mysql_query($insert_to_table1);
		 $insert_to_table2 = "insert into animal_age (age) values ('$animal_age');
		 mysql_query($insert_to_table2);
	}
}	
$obj_Connection = new Database();
$obj_Connection->getConnection();
$data = array();
$data['animal_type'] = "dog";
$data['animal_age'] = 12;
$obj_Connection->insertToTable($data);
$obj_Connection->closeConnection();
?>

Cheers!

Thanks for your response nav33n. The trouble comes in when I have multiple tables. One for food, animals, mechanical etc. Just want to create a something that will be able to work across the website.

[nav33n]

The example posted above can also deal with multiple tables. But, if you have different forms and different operations (like one form inserting a record to food table, another form to animals table, etc), you can have multiple functions. Sorry for my ignorance, but, I am not really sure what exactly is the problem :-/

[Venom Rush]

Would something like this work?

public function insertToTable($table, $columns, $data){
		 $insert_to_table = "insert into $table ($columns) values ('$data')";
		 mysql_query($insert_to_table);
}

Code that goes on the animals page

$obj_Connection = new Database();
$obj_Connection->getConnection();
$table = "animals";
$columns = "type, age, length";
$data = "dog, 5, 1.5m";
$obj_Connection->insertToTable($table, $columns, $data);
$obj_Connection->closeConnection();

Code that goes on the food page

$obj_Connection = new Database();
$obj_Connection->getConnection();
$table = "food";
$columns = "type, calories";
$data = "cake, 1000";
$obj_Connection->insertToTable($table, $columns, $data);
$obj_Connection->closeConnection();

[nav33n]

Umm.. Yeah, well, almost.. This looks good except the part where you insert string values to a varchar column of the table. Strings should be wrapped in ' single quotes.. So, pass the values accordingly.. ie.,

$obj_Connection = new Database();
$obj_Connection->getConnection();
$table = "food";
$columns = "type, calories";
$data = "[single_quote_here]'cake'[/single_quote], 1000";
$obj_Connection->insertToTable($table, $columns, $data);
$obj_Connection->closeConnection();

I hope you understood what I am talking bout.

[Venom Rush]

Yes I did. Thanks a lot nav33n ;)

[nav33n]

Great! You are welcome!

[Venom Rush]

Forgot to mark this as solved....but thanks for the link vrluckyin ;)