php Test2

Application Programming Interface, or API, defines the classes, methods, functions and variables that your application will need to call in order to carry out its desired task.

term - extension. The PHP code consists of a core, with optional extensions to the core functionality.

PHP's MySQL-related extensions, such as the mysqli extension, and the mysql extension, are implemented using the PHP extension framework.

• Mysqli extension
• Mysql extension:
• Php Data Objects (PDO)

• Create a mysqli object,
• connect to the MySQL server and open the database.
• Returns true on success and false on failure.

• protect against dangerous data reaching the database server.
• by separating the SQL from the user data and sending them separately to the server.  (Malicious data would be a text field containing Bugs Bunny; drop table patients;)
• Prepared statements improve performance.
• prepares the SQL statement for execution.
• ? is used for user entered variables.
• returns a mysqli_stmt object on success
•      returns false on failure.

• binds the specified values (user entered variables) to the ?s in the prepare statement.
• first parameter lists the data type of each ?
• s=string/date, i=int/bool, d=double, b=BLOB
• must be 1:1 ?s in prepare: variables in
• bind_param.

• binds the columns in the result set (the table data) to the specified variables.
• Returns true on success and
•     false on failure.

• The
• prepared statement is combined with the parameters values (if supplied) and statement is executed.
• Returns true on success,
•     false on failure.

• Fetch or return the next available row from the query results and place the
• data in the bound variables.
• Prepared statements come as binary so
• data types are recognized for what they are.
• Returns false when all the rows have been returned.
• A record pointer is used to keep track
• of the current row.

Returns the number of rows that were added/changed in the last execute statement.

Close the prepared stmt object.

Close the connection.

• A class is a definition of an object. A class contains data and the routines (methods) required to manipulate the data
• Defines attributes and methods of a particular type of object.
• It is a blue print for an object

• An instance of the class.
• Groups together data and routines in a data structure.
• You can create more than one object from a single class.

• One piece of data inside the class.
• Also called property, class variable, data member.
• Attributes should be declared as private or protected, where possible.

• A function inside a class.
• works on the attributes in the class to produce a result.
• works on only one object at a time.
• Also called property.
• Visibility can be:
•   private: only accessible by the class that defines it.
•   protected: accessible only within class itself and its inherited classes.
•   public (the default): can be accessed anywhere.
• Functions cannot be overloaded.
• To call a method: $objectname->methodname(parameter list)

• A method that is automatically called when the object is created.
• It is optional (but recommended) to add parameters to the constructor. These optional parameters can be used to assign initial values to the attributes when the object is created.
• If the constructor throws an exception on error, the object will not be created.

• A method that is automatically executed when an object is destroyed.
• typically used to release resources.
• example, closing a database connection.

• property is used to access private attributes from outside a class.
• A Get property returns the value of the attribute.
• A Set property receives a value as a parameter and assigns that value to the attribute.
• The parameter should be validated and only assigned to the attribute if valid.
• A public property can be directly accessed by code outside of the class.
• Private properties cannot be directly accessed by code outside the class.
• Protected properties can only be accessed within the class itself and its inherited classes.
• By default, properties are public.
• Style: provide the access modifier
•      (private, protected or public)
• Within a class, variable $this is used to refer to the current object. It allows you to access the properties and methods of the current object.
• The object access operator (->) is used to provide the access.