Multi layer architecture


SQL
	ACID properties
		Atomic -- The transaction runs completely or not at all
		Consistent -- Each transaction moves from one consistent state to another
		Independent -- Every transaction runs as if it were the only one on the system
		Durable -- Data changes survive hardware and software failure.
	Abort 
	Table vs database
	create table
		schema
		not null
		primary key
	types
		decimal(5,2)
		date and time types
		enum
		blob/longblob
	update tablename set columnname = value where ...
	delete from tablename where ...
	select columnname from tablename where .. order by columname limit 3
	alter table ...
	drop tablename
	describe table tablename
	joins
	nested queries (and in vs =)
	min and max count and average and group by
	insert into tablename values ( ...)
	database decomposition
		might cost speed
		reduces redundency and possibility of inconsistency
	Indexes

	
PHP
	Built in arrays
		$_GET
		$_POST
		$_COOKIE
		$_SESSION
		$_REQUEST
	Error supression with @
	isset($varname)
	empty($varname)	
	Error checking with die
	Arrays
		Not really arrays
		indexed by key, which can be string
		not always the same type
		foreach ($array as $item)
		foreach($array as %key => $item)
	Cookies
		Uses
		session cookies vs cookies with an expire time
		limits on size
		limits on domain/hostname
		Can be turned off
		$_COOKIE
	Session variables
		$_SESSION
		Needs cookies
		No reasonable size limits
		Expires when the session does
		Allows for privacy
		Requires cookies
	Loops
		while loops
		for loops
		foreach($array as $value)
		foreach($array as $index => $value	Functions
		default arguments
	Objects
		__construct
		__tostring
		$this->thing
		$this->method() vs method()
		class vs local vs global variables
	print_r
	header("location: ...")	
	Variables
		global
		superglobal
			$_REQUEST
			$_COOKIE
			$_POST
			$_GET
	Databases
		Know some way to fetch data like
			mysqli_query
			mysqli_num_rows
			mysqli_fetch_row
		mysqli_connect
		mysqli_select_db
		real_escape_string
		Error checking

Regular Expressions
	end of line chars ^ and $
	Repeat chars * and +
	Maybe char ?
	Sets of chars [abc] and [^abc]
	Ranges of chars [a-z]
	Special sets like /s and /S

Login
	Pick random number
	Verify random number
	passwords always encrypted!
	Know this is vulnurable to snoop attack