Related
I have a function like this:
public function myfunc ($arg1, $arg2, $arg3, $arg4, $arg5, $arg6, $arg7, $arg8) {
// do something
}
See? My function gets 8 arguments. Yes it works as well, but you know, it's ugly kinda ..! Isn't there any better idea? For example passing just one array contains all argument. Is it possible? or even something similar.
I do it this way..
$params = [];
put things in params..
$params[] = $a;
$params[] = $b;
pass the array to function
myFunction($params);
The function accept array as arg like, definition:
public function myFunction($params = []){}
Pass something in, and var_dump to check for yourself...
OK, now I know that it's an SQL operation you're doing then the best approach would be an associative array (assuming PDO and prepared statements).
public function myFunc (array $data)
{
// Using 3 values for example!
$stmt = $this -> pdo -> prepare ("INSERT INTO TABLE thisTable (
col1,
col2,
col3
) VALUES (
:val1,
:val2,
:val3
)");
if (false !== $stmt execute ($data))
{
return $stmt -> rowCount ();
} else {
return 0;
}
}
You'd call it with an array with the correct parameters in it:
$success = (bool) $obj -> myFunc (["val1" => "First value to insert",
"val2" => "Second value to insert",
"val3" => "Third value to insert"]);
It depends whether myfunc belongs to an exposed api or not (i.e.: public)
If it is public, the signature must break when you update the underlying model (your insert query), otherwise errors will be committed on the client-side.
With an array, you're losely mapping your Model to your Application, and you'd just expect programmers to send you the right values. With a tight/restricting mapping, this kind of error cannot happen.
I think that if you're saving an item in the database, you actually need all these fields. It is unelegant indeed, but it's not an anti-pattern as none of them are optional. And even if one or two were, it would not be a concern.
What you could do to improve your api is either:
If there are situation where you need to pass only a few of the parameters (i.e. most are optional or depend on a particular scenario) then you could specialize the method into separate functions. But PHP not accepting function polymorphism is quite a pain in the neck for this kind of things; you'd have to name the methods differently.
public function myfunctosavedatainaparticularcase ($arg1, $arg2, $arg3, $arg4)
// do something
}
public function myfunctosavedatainanotherparticularcase ($arg5, $arg6, $arg7, $arg8)
// do something
}
Use an object model mapper. For example, suppose you're saving a User data. You'd just pass a User object to the method:
public function myfunc (User $user)
// map fields to the User signature.
}
This would be acceptable if you're in control of the User class since you'd have to change it to reflect model changes.
Use an ORM to handle this for you. You'd only have to update the xml specifications of the schema after you decide to change the database model, all necessary changes would be propagated to the application automatically. Of course the objects definition would change but that is inevitable.
This is not so much a question about execution as it is a question about improving code. I am a 2nd year student, we started to touch on OOP recently and I am finally getting the hold of it....sort of.
I realize this is a very basic question, but what better place to learn from some of the best.
My Question
I have a class which creates a new match. My problem is that I am sure the code is unnecessary long and can get much improved (just keep in mind it is beginner level).Specifically I would like to know:
Can I change the below into 1 setter and 1 getter method?
I would like to use the rand() function for match ID can I do this inside the setter function of setMatchId or should it be done outside of the class?
Thank you very much for taking the time to read this.
<?php
class match{
private $matchId;
private $team1;
private $team2;
private $venue;
function __construct($pMatchId, $pTeam1, $pTeam2, $pVenue){
$this->matchId = $pMatchId;
$this->team1 = $pTeam1;
$this->team2 = $pTeam2;
$this->venue = $pVenue;
}
function setMatchId($pMatchId){
$this->matchId = $pMatchId;
}
function getMatchId(){
return $this->matchId;
}
function setTeam1($pTeam1){
$this->team1 = $pTeam1;
}
function getTeam1(){
return $this->team1;
}
function setTeam2($pTeam2){
$this->team2 = $pTeam2;
}
function getTeam2(){
return $this->team2;
}
function setVenue($pVenue){
$this->venue = $pVenue;
}
function getVenue(){
return $this->venue;
}
} // c;lass match
$x = new match("1", "Patriots", "Chargers", "Newlands");
echo $x->getMatchId();
echo'<br />';
echo $x->getTeam1();
echo'<br />';
echo $x->getTeam2();
echo'<br />';
echo $x->getVenue();
?>
How often are teams or venues going to change for a match? I think you should get rid of the setters since you're already providing all the necessary data through your constructor.
You can indeed change your code to work with a single getter and setter methods, but I'd strongly discourage that. IDE's won't be able to assist you with code completion if you implement such methods but, most importantly, you should never blindly implement getters and setters in your entities if they have no reason to exist.
Let the design guide you on that. Start by passing everything your objects need through their constructors and only add getters/setters when you need them, not the other way around.
In terms of the randomness of the ID, you could use UUIDs for them. You could use this library to create them. I'd pass them through its constructor as well.
You can use __set and __get magic methods of PHP.
private $data = array(); // define property array
public function __set($name, $value) // set key and value in data property
{
echo "Setting '$name' to '$value'\n";
$this->data[$name] = $value;
}
public function __get($name) // get propery value
{
if(isset($this->data[$name])) {
return $this->data[$name];
}
}
You can write your existing code as below:-
class Match{
private $data = [];
function __construct($property=[]){
if(!empty($property)){
foreach($property as $key=>$value){
$this->__set($key,$value);
}
}
}
public function __set($name, $value) // set key and value in data property
{
// echo "Setting '$name' to '$value'\n";
$this->data[$name] = $value;
}
public function __get($name) // get propery value
{
if(isset($this->data[$name])) {
return $this->data[$name];
}
}
}
Set properties using construct method
$x = new match(["matchId"=>"1", "team1"=>"Patriots","team2"=>"Chargers","venue"=>"Newlands"]);
echo '<pre>'; print_r($x);
Set properties without construct method
$x = new match;
$x->matchId = '1'; // 1
$x->team1 = 'team1'; // Patriots
$x->team2 = 'Chargers'; // Chargers
$x->venue = 'Newlands'; // Newlands
echo '<pre>'; print_r($x);
output:-
Match Object
(
[data:Match:private] => Array
(
[matchId] => 1
[team1] => Patriots
[team2] => Chargers
[venue] => Newlands
)
)
Now you can access and set propery by below way:-
// Get all properties values
echo $x->matchId; // 1
echo $x->team1; // Patriots
echo $x->team2; // Chargers
echo $x->venue; // Newlands
// Overwrite existing values
$x->team1 = 'new team1';
// Get updated value
echo $x->team1; // new team1
Hope it will help you :)
The first question:
Can I change the below into 1 setter and 1 getter method?
[EDIT] Reply to first comment:
You can, but you shouldn't.. To me it's better keep all setters and getters parted. You might want to get only a specific field when using your match object instance in your code. So if you need to get team1 or team2 it's better to have two different getter methods.
The second question:
I would like to use the rand() function for match ID can I do this inside the setter function of setMatchId or should it be done outside of the class?
Well, in my opinion, the best way of handle it is to disallow any access to the $matchId field making it private and removing any setter method.
Then, you should place the rand generation inside the constructor or, if you want to keep it parted in a specific function you could make a public getter like this:
public getMatchId(){
if ($this->matchId != null)
return $this->matchId
// Generate it with rand()
$this->matchId = rand()
return $this->matchId;
}
In the constructor then simply call the getMatchId() method.
By the way, this solution doesn't help you with getting a unique match identifier, to achieve that you should generate it not purely randomly but using something that is dependant of the informations of the Match (for instance you could use a combination of team1, team2 and venue) and/or keep track of used matchid (a static field or a database could be helpful)
[EDIT] Reply to second comment:
I'm using the if statement in the getter because this getter is thought to generate the $matchId when it's called for the first time, while it'll always return the previously generated $matchId for the other calls.
You question made me think of another possible implementation. If you want to avoid the if then you should generate the $matchId in the constructor.
This way should be fine:
public __construct($team1, $team2, $venue){
$this->matchId = rand();
$this->team1 = $team1;
$this->team2 = $team2;
$this->venue = $venue
}
public getMatchId(){
return $this->matchId;
}
There are multiple answers covering how to do setters and getters in various degrees of complexity and magic. In this post I would rather focus on the design quality of your class Match. This is based on the design idea related to what do you want to use your class for?
Some typical statements answering this question:
Keep record of a given match – In other words it needs to hold information related to one match, i.e. venue, homeTeam, awayTeam, result?, and possibly a matchId related to storing the result somewhere
Set the result of a match – You'll create the match, and then a little later you'll set the actual result of the match.
Store a match – If you don't store it anywhere it is kind of futile to keep track of the match, so most likely you would need some interface either to a database, or some mean to get all information related to a match ready for storing into a file or similar
Ability to retrieve the details of a match – If not getting all information at the same time, you could opt for a getter for the specific values you'll want.
For me I don't see the need for changing the team or venue, as that would mean a new match in my world. And I would definitively not implement a generic setter which would allow for setting whatever to whatever. A generic setter is a security risk in my world.
Alternate implementation
Adhering to the statements given I would write something similar to this:
<?php
class Match {
private $matchId;
private $homeTeam;
private $awayTeam;
private $venue;
private $result;
function __construct($venue, $homeTeam, $awayTeam, $matchId = NULL) {
$this->venue = $venue;
$this->homeTeam = $homeTeam;
$this->awayTeam = $awayTeam;
if (is_null($matchId)) {
$this->matchId = uniqid();
} else {
$this->matchId = $matchId;
}
// In PHP7: $this->matchId = $matchId ?: uniqid();
$this->result = "";
}
function setResult($result){
$this->result = $result;
}
function getAll(){
return array($this->venue, $this->homeTeam, $this->awayTeam,
$this->matchId, $this->result);
}
function __get($name) {
if (property_exist($this, $name)) {
return $this->$name;
}
}
function __set($name, $value) {
if (property_exist($this, $name)) {
$this->$name = $value;
}
}
?>
Some comments related to this code:
homeTeam and awayTeam – Having variables name team1 or team2 is a code smell, to me. I would either create an array for those, or find better names. In this case I opted for better names to make a clear distinction between the two variables.
__construct() – When creating a match the default value for matchId indicates that it will be set to a uniqid(). I consider this a better practice rather then using a random value. And it still allows for setting a specific match id if you want to provide this.
Based on the assumption that you don't know the result when the match is created, the result is set to an empty string for starters.
setResult() – As this is the only part of a match I foresee changing I provided a setter for this value.
getAll() – This returns an array of all the values, ready for storing somewhere. If you like this could easily be changed into a comma separated string or whatever format you would like for post-processing. It could even be a dictionary, but I just used a simple array to keep it simple.
__get() and __set() – Contrary to some of the other answers this getter (and setter) is a little safer to use as it verifies that the actual property is defined in this class using property_exist().
I'm not sure if I would actually have the generic setter, but if you'd like one, this is a better option as it doesn't allow for creation of new properties to your class at runtime.
Usage of class
Here is some simple usage of the class (if my untested code actually works, that is):
<!php
$m = new Match("Newlands", "Patriots", "Chargers");
// Time passes
$m->setResult("102-32");
echo 'In the game ' . $m->homeTeam . ' vs ' . $m->awayTeam
echo ' at ' . $m ->venue ' the result was ' . $m->result . ' <br />'
// Append the match to a file
$fp = fopen('allmatches.csv', 'a');
fputcsv($fp, $m->getAll());
fclose($fp);
?>
This uses fputcsv to format the array into a line in the csv format. Having a method or some way to create a match from an array is left as an exercise. You possibly have a static method taking a file name as a parameter, and return an array of matches.
There is no good or bad model when you aren't trying to solve a well-defined problem just like there's no good answer to a bad question.
Before even worrying about things such as getters and setters you need to determine the purpose of the model and what problem it is trying to solve.
I understand that this is probably just a modeling exercise, but if you want it to have any value, start by defining your problem domain and then work out the solution.
For instance, if you are modeling an application service that allows to query a list of matches, then perhaps Match is a simple immutable data structure that acts as a Data Transfer Object.
If you were modeling a ViewModel that is meant to be 2-way bound to a CRUD screen allowing to update the details of a Match then perhaps you'd have a data container with public getters and setters like you had.
If you were crafting a tournament system domain model and had a use case such as: "Tournament administrators will enter the scoring of a match after it's completion. The outcome will be automatically resolved by the system. The possible results are that the home/away team wins or a draw."
Then perhaps Match would carry a behavior such as (pseudo-code):
scoring = new Scoring(homeTeamScore: 2, awayTeamScore: 3);
match.complete(scoring);
match.outcome(); //-> MatchOutcome.AwayTeamWon
As you can see, the model should be a solution to a well-defined problem. It should model the reality of that problem (not the real world), no more, no less.
I would like to use the rand() function for match ID can I do this
inside the setter function of setMatchId or should it be done outside
of the class?
The generation of an entity's identity is usually not the responsibility of the identity itself in respect to the Single Responsibility Principle. The algorithm that generates the identity may change independently of the Match concept itself.
First of all, there's nothing bad in having several get/set methods, unless you're coding on a 64kb RAM machine (Where you probably would use C, Lua, or such instead of PHP). If they're all doing (almost) the same thing and you think they're messing code up, put them on the very end of your class, so they don't block your vision ;-).
For the practical altering of your code:
If you have several members which differ only by data but actually represent the same kind, like team1, team2 puting them into an array and use a get/setByIndex is legit.
(Take care: I didn't use PHP for hundreds of years or so, there might me syntactical mistakes)
Example:
function setTeamByIndex($pIndex, $pTeam){
$this->teams[$pIndex] = $pTeam;
}
function getTeamByIndex($pIndex){
return $this->team[$pIndex];
}
Alternatively, in other language it's common to return multiple values. This is not possible in PHP, but there's a workaround:
setTeamsFromArray
-- receives an Array with teams and applies the given teams by their key.
getAllTeamsArray
-- returns an Array, containing all teams.
function setTeamsFromArray($pTeams){
foreach ($pTeams as $key=>$team) {
$this->teams[$key] = $team
}
}
function getAllTeamsArray(){
return array( $this->team1, $this->team2 )
}
echo(getAllTeamsArray()[0]) -> echos team1
echo(getAllTeamsArray()[1]) -> echos team2
In my opinion, this is all one reasonable could do in your case.
Shrinking stuff down is not always reasonable and 10 4liners are, most of the time, better than 1 40liner.
for geter and seter you can use __call() magic method for example realize the geters and setters
public function __call($name, $arguments)
{
// TODO: Implement __call() method.
$method = substr($name,0,3);
$key = strtolower(substr($name,3,strlen($name)));
if($method == 'set') {
$this->_data[$key] = $argument[0]
return $this;
} elseif($method=='get') {
if(isset($this->_data[$key])) {
return $this->_data[$key];
} else {
return null;
}
}
}
this is simple realization getter and setter automaticaly generate.
Imagine a "Games" class used to track games between opponents. Is it better OOP to have 1 method to retrieve games based on user input parameters or is it better to have multiple methods specific to the retrieval goals?
class Games {
function get_games($game_id = NULL, $stadium_id = NULL, $start_date = NULL,
$end_date = NULL, $count = 999); {}
}
VS
class Games {
function get_all_games($count = 999); {}
function get_game_by_id($game_id = 1); {}
function get_games_by_stadium($stadium_id = 1); {}
function get_games_by_dates($start_date = NULL; $end_date = NULL) {}
}
Explanation of benefits and any coding / snytax tips would be appreciated. Thanks.
The more I practice OOP the more I find myself following a rule about passing parameters to methods. Kind of like having many levels of nested if statements, I find that if I have more than two I might be doing something wrong.
Keep your code simple. You're writing a method that does something, not a block of procedural code that does everything. If you want to get a game, then get a game. If you want to get a list for a date range, then do that.
However I would point out that you don't really need get_all_games() - You can just allow for get_games_by_dates() to be passed with no parameters. If it doesn't get any then it would get the games for every date since forever (all the games)
I would always err on the side of OOP code. the reason being is that it makes you code much easier to maintain and read. The more functions you have the easier it is to follow code later on down the road
I would go for separate methods since you are using lots of paramaters with default values.
If you want to get all games you would have to do:
$games->get_games(NULL, NULL, NULL, NULL, 999);
Assuming that your get_....() functions are returning all game data, I would write a single function to return this data, based on an id passed in, and write a series of find_...() functions to return an array of found ids. This will have the added benefit of making it easier to override the data retrieval code in decendant classes.
class Games {
public function get_game($game_id) {
// Return game details (array/object) for $game_id, or FALSE if not found.
}
public function find_all_games() {
// Return array of ids for all games.
}
public function find_games_by_dates($start_date = NULL, $end_date = NULL) {
// Return array of ids between $start_date and $end_date unless NULL.
}
}
You can then call:
$oGames = new Games() ;
$aGames = $oGames->find_all_games() ;
foreach($aGames as $id) {
$aGame = $oGames->get_game($id) ;
if($aGame !== FALSE) { // This check might be skipped if you trust the array of ids from find_all_games().
// Assuming an array is returned.
echo "Game Found: ".$aGame['name']."\n" ;
}
}
The benefit of "multiple methods specific to the retrieval goals" is that you can add/remove goals. The problem with using one monolithic function with a bunch of parameters is that, should you decide to add/remove a way to get games, you'd have to change the interface. Which would break any code that uses it.
Each method should be as concise as possible, performing only one function.
Some quick background info: I'm coding up a site which matches books to the classes they're required for.
I have two pieces of data that I need to represent in my code-- which books go with which classes, and the data (titles, authors, pricing, etc.) on these books.
Currently I represent this all with two arrays: $classArray, and $Books_data.
The advantage of this approach over a one-variable approach is that I don't repeat myself-- if a Book is required multiple times for different classes, only the ISBN needs to be stored in the $classArray and I can store the data in the $Books_array. This advantage is especially poignant because I have to query the pricing data from API's on the fly. If I only had a $classBooksArray, I'd have to loop the query responses into a big array, repeating myself (seemingly) unnecessarily.
The disadvantage of this approach is that these variables follow each other almost everywhere like Siamese twins. Nearly every function that needs one, needs the other. And my coding spidey sense tells me it might be unnecessary.
So, what would be the best way to store this data? Two arrays, one array, or some other approach I haven't mentioned (e.g. passing by reference).
Why not an associative which has two keys - one pointing to an array of classes, one to store Books
data?
$allData = array("classes" => &$classArray, "books" => &$Books_data);
That way you're only passing around 1 variable (less clutter) but retain all the benefits of separate data stores for books and classes.
Though, to be honest, if it's just TWO sets of data, so IMHO your spidey sense is wrong - passing both as separate parameters is perfectly fine. Once you get into a set of siamise sextuplet variables, then the above approach starts to actually bring benefits.
A multidimensional array.
$collection = array(
'classes' => array( /* Contents of $classArray */),
'books' => array( /* Contents of $Books_data */)
);
function some_function($collection) {
// looping over books
foreach ($collection['books'] as $book) {
// yadda yadda
}
}
Or better yet a class:
/* Define */
class Collection {
private $books;
private $classes;
public function __construct($classes = array(), $books = array()) {
$this->books = $books;
$this->classes = $classes;
}
public function addBook($book) {
$this->books[] = $book;
}
public function addClass($class) {
$this->classes[] = $class;
}
public function get_classes() {
return $this->classes;
}
public function get_books() {
return $this->books;
}
}
function some_function(Collection $col) {
// looping over books
foreach ($col->get_books as $book) {
// yadda yadda
}
}
/* Usage */
$collection = new Collection(); // you also could pass classes and books in the
// constructor.
$collection->addBook($book);
somefunction($collection);
If your datas were a database, your current proposal being a normal form would be canonical. The two variables would just become tables and ISBN a foreign key to books table (with a third table as a class has several books). I would probably stick with the current implementation as it will be very easy to transform to database when that will be necessary (and it usually happens faster than expected).
EDIT: a comment, say it is already in a database... what I do not understand is why you would want to store a full database in memory instead of just keeping what is necessary for the current task.
Let's be OO and put the arrays into an object. Define a class with those properties, load it up, and call its methods. Or, if you must have other functions operating with the object's data, pass the instance around. Disallow direct access to the data, but provide methods for extracting the salient info.
class book_class_association {
protected $books_to_classes = array();
protected $classes_to_books = array();
function __construct() {
$this->books_to_classes = array(
'mathbook1' => array('math'),
'mathbook2' => array('math'),
);
$this->classes_to_books = array(
'math' => array('mathbook1', 'mathbook2'),
);
}
function classes_for_book( $class_name ) {
return $this->books_to_classes[$class_name];
}
function books_for_class( $class_name ) {
return $this->classes_to_books[$class_name];
}
}
Is there a reason you are not storing this data in a database and then querying the database? It is a many to many relationship, and you would need 3 tables - class , book, and class_book_intersection.
So for example, you ui could have "select class" from a list, where the list is derived from the rows in class.
Then if the class id selected is 123. The query would then be something like:
Select book.title, book.cost
from book
inner join class_book_intersection
on
class_book_intersection.classid = 123 and
class_book_intersection.bookid = book.bookid
What is the best way of working with calculated fields of Propel objects?
Say I have an object "Customer" that has a corresponding table "customers" and each column corresponds to an attribute of my object. What I would like to do is: add a calculated attribute "Number of completed orders" to my object when using it on View A but not on Views B and C.
The calculated attribute is a COUNT() of "Order" objects linked to my "Customer" object via ID.
What I can do now is to first select all Customer objects, then iteratively count Orders for all of them, but I'd think doing it in a single query would improve performance. But I cannot properly "hydrate" my Propel object since it does not contain the definition of the calculated field(s).
How would you approach it?
There are several choices. First, is to create a view in your DB that will do the counts for you, similar to my answer here. I do this for a current Symfony project I work on where the read-only attributes for a given table are actually much, much wider than the table itself. This is my recommendation since grouping columns (max(), count(), etc) are read-only anyway.
The other options are to actually build this functionality into your model. You absolutely CAN do this hydration yourself, but it's a bit complicated. Here's the rough steps
Add the columns to your Table class as protected data members.
Write the appropriate getters and setters for these columns
Override the hydrate method and within, populate your new columns with the data from other queries. Make sure to call parent::hydrate() as the first line
However, this isn't much better than what you're talking about already. You'll still need N + 1 queries to retrieve a single record set. However, you can get creative in step #3 so that N is the number of calculated columns, not the number of rows returned.
Another option is to create a custom selection method on your TablePeer class.
Do steps 1 and 2 from above.
Write custom SQL that you will query manually via the Propel::getConnection() process.
Create the dataset manually by iterating over the result set, and handle custom hydration at this point as to not break hydration when use by the doSelect processes.
Here's an example of this approach
<?php
class TablePeer extends BaseTablePeer
{
public static function selectWithCalculatedColumns()
{
// Do our custom selection, still using propel's column data constants
$sql = "
SELECT " . implode( ', ', self::getFieldNames( BasePeer::TYPE_COLNAME ) ) . "
, count(" . JoinedTablePeer::ID . ") AS calc_col
FROM " . self::TABLE_NAME . "
LEFT JOIN " . JoinedTablePeer::TABLE_NAME . "
ON " . JoinedTablePeer::ID . " = " . self::FKEY_COLUMN
;
// Get the result set
$conn = Propel::getConnection();
$stmt = $conn->prepareStatement( $sql );
$rs = $stmt->executeQuery( array(), ResultSet::FETCHMODE_NUM );
// Create an empty rowset
$rowset = array();
// Iterate over the result set
while ( $rs->next() )
{
// Create each row individually
$row = new Table();
$startcol = $row->hydrate( $rs );
// Use our custom setter to populate the new column
$row->setCalcCol( $row->get( $startcol ) );
$rowset[] = $row;
}
return $rowset;
}
}
There may be other solutions to your problem, but they are beyond my knowledge. Best of luck!
I am doing this in a project now by overriding hydrate() and Peer::addSelectColumns() for accessing postgis fields:
// in peer
public static function locationAsEWKTColumnIndex()
{
return GeographyPeer::NUM_COLUMNS - GeographyPeer::NUM_LAZY_LOAD_COLUMNS;
}
public static function polygonAsEWKTColumnIndex()
{
return GeographyPeer::NUM_COLUMNS - GeographyPeer::NUM_LAZY_LOAD_COLUMNS + 1;
}
public static function addSelectColumns(Criteria $criteria)
{
parent::addSelectColumns($criteria);
$criteria->addAsColumn("locationAsEWKT", "AsEWKT(" . GeographyPeer::LOCATION . ")");
$criteria->addAsColumn("polygonAsEWKT", "AsEWKT(" . GeographyPeer::POLYGON . ")");
}
// in object
public function hydrate($row, $startcol = 0, $rehydrate = false)
{
$r = parent::hydrate($row, $startcol, $rehydrate);
if ($row[GeographyPeer::locationAsEWKTColumnIndex()]) // load GIS info from DB IFF the location field is populated. NOTE: These fields are either both NULL or both NOT NULL, so this IF is OK
{
$this->location_ = GeoPoint::PointFromEWKT($row[GeographyPeer::locationAsEWKTColumnIndex()]); // load gis data from extra select columns See GeographyPeer::addSelectColumns().
$this->polygon_ = GeoMultiPolygon::MultiPolygonFromEWKT($row[GeographyPeer::polygonAsEWKTColumnIndex()]); // load gis data from extra select columns See GeographyPeer::addSelectColumns().
}
return $r;
}
There's something goofy with AddAsColumn() but I can't remember at the moment, but this does work. You can read more about the AddAsColumn() issues.
Here's what I did to solve this without any additional queries:
Problem
Needed to add a custom COUNT field to a typical result set used with the Symfony Pager. However, as we know, Propel doesn't support this out the box. So the easy solution is to just do something like this in the template:
foreach ($pager->getResults() as $project):
echo $project->getName() . ' and ' . $project->getNumMembers()
endforeach;
Where getNumMembers() runs a separate COUNT query for each $project object. Of course, we know this is grossly inefficient because you can do the COUNT on the fly by adding it as a column to the original SELECT query, saving a query for each result displayed.
I had several different pages displaying this result set, all using different Criteria. So writing my own SQL query string with PDO directly would be way too much hassle as I'd have to get into the Criteria object and mess around trying to form a query string based on whatever was in it!
So, what I did in the end avoids all that, letting Propel's native code work with the Criteria and create the SQL as usual.
1 - First create the [get/set]NumMembers() equivalent accessor/mutator methods in the model object that gets returning by the doSelect(). Remember, the accessor doesn't do the COUNT query anymore, it just holds its value.
2 - Go into the peer class and override the parent doSelect() method and copy all code from it exactly as it is
3 - Remove this bit because getMixerPreSelectHook is a private method of the base peer (or copy it into your peer if you need it):
// symfony_behaviors behavior
foreach (sfMixer::getCallables(self::getMixerPreSelectHook(__FUNCTION__)) as $sf_hook)
{
call_user_func($sf_hook, 'BaseTsProjectPeer', $criteria, $con);
}
4 - Now add your custom COUNT field to the doSelect method in your peer class:
// copied into ProjectPeer - overrides BaseProjectPeer::doSelectJoinUser()
public static function doSelectJoinUser(Criteria $criteria, ...)
{
// copied from parent method, along with everything else
ProjectPeer::addSelectColumns($criteria);
$startcol = (ProjectPeer::NUM_COLUMNS - ProjectPeer::NUM_LAZY_LOAD_COLUMNS);
UserPeer::addSelectColumns($criteria);
// now add our custom COUNT column after all other columns have been added
// so as to not screw up Propel's position matching system when hydrating
// the Project and User objects.
$criteria->addSelectColumn('COUNT(' . ProjectMemberPeer::ID . ')');
// now add the GROUP BY clause to count members by project
$criteria->addGroupByColumn(self::ID);
// more parent code
...
// until we get to this bit inside the hydrating loop:
$obj1 = new $cls();
$obj1->hydrate($row);
// AND...hydrate our custom COUNT property (the last column)
$obj1->setNumMembers($row[count($row) - 1]);
// more code copied from parent
...
return $results;
}
That's it. Now you have the additional COUNT field added to your object without doing a separate query to get it as you spit out the results. The only drawback to this solution is that you've had to copy all the parent code because you need to add bits right in the middle of it. But in my situation, this seemed like a small compromise to save all those queries and not write my own SQL query string.
Add an attribute "orders_count" to a Customer, and then write something like this:
class Order {
...
public function save($conn = null) {
$customer = $this->getCustomer();
$customer->setOrdersCount($customer->getOrdersCount() + 1);
$custoner->save();
parent::save();
}
...
}
You can use not only the "save" method, but the idea stays the same. Unfortunately, Propel doesn't support any "magic" for such fields.
Propel actually builds an automatic function based on the name of the linked field. Let's say you have a schema like this:
customer:
id:
name:
...
order:
id:
customer_id: # links to customer table automagically
completed: { type: boolean, default false }
...
When you build your model, your Customer object will have a method getOrders() that will retrieve all orders associated with that customer. You can then simply use count($customer->getOrders()) to get the number of orders for that customer.
The downside is this will also fetch and hydrate those Order objects. On most RDBMS, the only performance difference between pulling the records or using COUNT() is the bandwidth used to return the results set. If that bandwidth would be significant for your application, you might want to create a method in the Customer object that builds the COUNT() query manually using Creole:
// in lib/model/Customer.php
class Customer extends BaseCustomer
{
public function CountOrders()
{
$connection = Propel::getConnection();
$query = "SELECT COUNT(*) AS count FROM %s WHERE customer_id='%s'";
$statement = $connection->prepareStatement(sprintf($query, CustomerPeer::TABLE_NAME, $this->getId());
$resultset = $statement->executeQuery();
$resultset->next();
return $resultset->getInt('count');
}
...
}