I would like to implement filter in database driven webpage. Some of the option may not have to be selected some of them may do. Filter as you know can change. The question is, is there any way to build a general query like:
SELECT * FROM database.table WHERE name='$name', author='$author', pages='$pages', font='$font';
When once user might just want to choose all books from the particular author, but doesnt care about any other limitations. Other time user might want to get all books with the same name, etc. The thing is, can I in that case just pass NULL or something like that for pages=$pages if I don't care how many pages it will have, but I want to use the same query for other possible filters set by user.
SELECT is the universal MySQL query you're looking for.
As far as I know, you can't disable a specific WHERE condition by passing a null or something else.
What you can do though, is to remove the condition from your query when you don't need it. Meaning you will have to build your query dynamically depending on the filters you'll want.
You'd solve that in PHP by constructing the query dynamically.
$params = [];
foreach ( [ 'name', 'author', 'pages', 'font' ] as $p )
if ( ! empty( $_REQUEST[$p] ) )
$params[$p] = $_REQUEST[$p];
$sth = $db->prepare( "SELECT * FROM database.table WHERE " .
implode( " AND ", array_map( function($k) { return "$k=?"; }, array_keys($params) ) )
);
$sth->execute( array_values( $params ) );
Related
I am making a real estate related app and I've been having a hard time figuring out how to set up the query so that it would return "Only Apartments or Duplexes within selected areas" I'd like to user to be able to find multiple types of property in multiple selected quadrants of the city.
I have a database with a column "type" which is either "Apartment", "House", "Duplex", "Mobile"
In another column I have quadrant_main with values: "NW", "SW", "NE", "SE".
My code works when there is only 1 quadrant selected, but when I select multiple quadrants, I seem to get results which includes ALL the property types from the second or third or 4th quadrant, instead of only "Apartment" and "Duplex" or whatever types the user selects... Any help will be appreciated! thx in advance.
My controller function looks like this:
public function quadrants()
{
$input = \Request::all();
$currentPage = null;
$column = "price";
$order = "desc";
//
// Looks like the input is like 0 => { key: value } ...
// (an Array of key/value pairs)
$q = Listing::where('status','=','Active')->where(function($query) {
$input = \Request::all();
$currentPage = null;
$typeCount = 0;
$quadrantCount = 0;
foreach( $input as $index => $object ) {
$tempObj = json_decode($object);
$key = key((array)$tempObj);
$val = current((array)$tempObj);
if ( $key == "type" ) {
if ( $typeCount > 0 ) {
$query->orWhere('type', '=', $val );
}
else {
$query->where('type', '=', $val );
$typeCount++;
}
}
if ( $key == "quadrant_main" ) {
if ( $quadrantCount > 0 ) {
$query->orWhere('quadrant_main', '=', $val );
}
else {
$query->where('quadrant_main', '=', $val );
$quadrantCount++;
}
}
// else {
// $query->orWhere($key,$val);
// }
}
if( $currentPage ) {
//Force Current Page to Page of Val
Paginator::currentPageResolver(function() use ($currentPage) {
return $currentPage;
});
}
});
$listings = $q->paginate(10);
return $listings;
Looking at your question, its a bit confusing and not much is given to answer definitely. Probable causes of your troubles may be bad data in database, or maybe corrupted input by user.
Disclaimer: Please note that chances are my answer will not work for you at all.
In that case please provide more information and we will work things
out.
There is one thing that I think you have overlooked and thus you are getting awry results. First let me assume a few things.
I think a sample user input should look like this:
array(
0: '{type: Apartment}',
1: '{type: Duplex}',
2: '{quadrant_main: NW}',
3: '{quadrant_main: SW}',
)
What the user meant was give me any apartment or duplex which belongs in NW or SW region.
So after your loop is over, the final SQL statement should be something like this:
Oh and while we are at SQL topic, you can also log the actual
generated SQL query in laravel so you can actually see what was the
final SQL getting generated. If you can post it here, it would help a
lot. Look here.
select * from listings where status = 'Active' and (type = 'Apartment' or type = 'Duplex' and quadrant_main = 'NW' or quadrant_main = 'SW');
What this query will actually produce is this:
Select any listing which is active and:
1. Type is an apartment, or,
2. Type is a duplex, or,
3. Quadrant is SW, and,
4. Quadrant is NW
So assuming you have a database like this:
id|type|quadrant_main
=====================
1|Apartment|NW
2|Apartment|SW
3|Apartment|NE
4|Apartment|SE
5|Duplex|NW
6|Duplex|SW
7|Duplex|NE
8|Duplex|SE
9|House|NW
10|House|SW
11|House|NE
12|House|SE
You will only receive 1, and 5 in the result set. This result set is obviously wrong, plus it is depended on NW because that was the and condition.
The correct SQL query would be:
select * from listings where status = 'Active' and (type = 'Apartment' or type = 'Duplex') and (quadrant_main = 'NW' or quadrant_main = 'SW');
So structure your L5 app such that it produces this kind of SQL query. Instead of trying to cram everything in one loop, have two loops. One loop should only handle type and another loop should only handle quadrant_main. This way you will have the necessary and condition in the right places.
As a side note:
Never directly use user input. Always sanitize it first.
Its not a best practice to put all your logic in the controller. Use repository pattern. See here.
Multiple where clauses are generally applied via Criteria. Check that out in the above linked repository pattern.
You code logic is very complicated and utterly un-necessary. Instead of sending JSON objects, simply send the state of checkboxes. Don't try to generalize the function by going in loop. Instead handle all checkboxes one by one i.e. is "Apartments" selected, if yes, add that to your clause, if not, don't add.
I have a draggable div in which the position is being saved to database with user_id set to unique. How would I check if user_id exists.. and if it does, update the other 3 columns.. If it does not exist, insert new row. I have read to use "ON DUPLICATE KEY UPDATE", but having a hard time implementing it. Any thoughts?
As explained by #N.B. - Working solution
global $wpdb;
$_POST['user_id'];
$_POST['div_id'];
$_POST['x_pos'];
$_POST['y_pos'];
$user_id = $_POST['user_id'];
$div_id = $_POST['div_id'];
$x_pos = $_POST['x_pos'];
$y_pos = $_POST['y_pos'];
$wpdb->query($wpdb->prepare(" INSERT INTO coords
(user_id, div_id, x_pos, y_pos)
VALUES (%d, %s, %d, %d)
ON DUPLICATE KEY UPDATE
x_pos = VALUES(x_pos), y_pos = VALUES(y_pos)",
$user_id,
$div_id,
$x_pos,
$y_pos
));
As #N.B. pointed out in the comments, while the first method I submitted works, it is open to race conditions. I'd like to thank him for pointing that out. Here is that first solution with race conditions:
$user_exists = $wpdb->get_var(
$wpdb->prepare("SELECT user_id FROM coords WHERE user_id = %d", $user_id)
);
if($user_exists) {
// Do Update
}
else {
// Do Insert
}
These race conditions are astronomical, as an insert must finish executing in the time between the first query returning and the next insert query. But the race condition exists none-the-less, and therefore could happen at some point in time.
However your database is still safe. When it occurs it won't duplicate the data, but rather it will throw a wpdb error that a unique key already exists and the insert will silently fail (it won't terminate the script and it won't output the error unless error reporting is turned on).
WordPress database error: [Duplicate entry '3' for key 'PRIMARY']
Amazingly, the above technique is used in the Wordpress core and by countless plugin and theme authors, and I could only find two instances of 'ON DUPLICATE' being used correctly in the Wordpress core. So a large chunk of the internet runs with multiple instances of this race condition seemingly just fine, just to give you an idea of the astronomical chance we're talking about.
Regardless of the chance, to use it is bad practice. As N.B. commented, the database should worry about the data and not PHP.
The Real Solution
Wordpress, for whatever reason, does not have an 'INSERT ON DUPLICATE UPDATE' function, which means you have to either write up a query each time with $wpdb->query or build your own function to handle it. I went with writing a function because writing wpdb->query each time is a pain and brings the user one layer closer to accidental mysql injection. Also development speed.
/**
* Insert on Duplicate Key Update.
*
* Wordpress does not have an 'insert on duplicate key update' function, which
* forces user's to create their own or write standard queries. As writing
* queries is annoying and open to mysql injection via human error, this function
* automates this custom query in an indentical fashion to the core wpdb functions.
* Source: http://stackoverflow.com/a/31150317/4248167
*
* #global wpdb $wpdb
* #param string $table The table you wish to update.
* #param array $data The row you wish to update or insert, using a field => value associative array.
* #param array $where The unique keys that you want to update at or have inserted, also a field => value array.
* #param array $data_formats Wordpress formatting array for the data. Will default to %s for every field.
* #param array $where_formats Wordpress formatting array for the where. Will default to %s for every field.
* #return boolean True if successfully inserted or updated the row.
*/
function insertOrUpdate($table, $data, $where, $data_formats = array(), $where_formats = array())
{
if(!empty($data) && !empty($where)) {
global $wpdb;
// Data Formats - making sure they match up with the data.
$default_data_format = (isset($data_formats[0])) ? $data_formats[0] : '%s';
$data_formats = array_pad($data_formats, count($data), $default_data_format);
$data_formats = array_splice($data_formats, 0, count($data));
// Where Formats - making sure they match up with the where data.
$default_where_format = (isset($where_formats[0])) ? $where_formats[0] : '%s';
$where_formats = array_pad($where_formats, count($where), $default_where_format);
$where_formats = array_splice($where_formats, 0, count($where));
// Get Fields
$data_fields = array_keys($data);
$where_fields = array_keys($where);
// Create Query
$query =
"INSERT INTO $table" .
" (" . implode(', ', array_merge($data_fields, $where_fields)) . ")" .
" VALUES(" . implode(', ', array_merge($data_formats, $where_formats)) . ")" .
" ON DUPLICATE KEY UPDATE";
// Compile update fields and add to query
$field_strings = array();
foreach($data_fields as $index => $data_field) {
$field_strings[] = " $data_field = " . $data_formats[$index];
}
$query .= implode(', ', $field_strings);
// Put it all together - returns true on successful update or insert
// and false on failure or if the row already matches the data.
return !!$wpdb->query(
$wpdb->prepare(
$query,
array_merge(
array_merge(
array_values($data),
array_values($where)
),
array_values($data)
)
)
);
}
return false;
}
To use it, you simply enter parameters just like you would with a $wpdb->update function call.
insertOrUpdate(
'testing_table',
array('column_a' => 'hello', 'column_b' => 'world'),
array('id' => 3),
array('%s', '%s'),
array('%d')
);
In your case, it would be:
insertOrUpdate(
'coords',
array('div_id' => $div_id, 'x_pos' => $x_pos, 'y_pos' => $y_pos),
array('user_id' => $user_id),
array('%d', '%d', '%d'),
array('%d')
);
Or you can just use a default formatting:
insertOrUpdate(
'coords',
array('div_id' => $div_id, 'x_pos' => $x_pos, 'y_pos' => $y_pos),
array('user_id' => $user_id),
array('%d')
);
Or you can ignore the formatting which will default to formatting as strings:
insertOrUpdate(
'coords',
array('div_id' => $div_id, 'x_pos' => $x_pos, 'y_pos' => $y_pos),
array('user_id' => $user_id)
);
If you find any issues just let me know.
I have a data table with 7 columns and 400 records. One of them is budget. I want to group the 400 rows by budget so that I get an array like this:
[budget]=>array(
[0]=>array(
[column1]=>'1',
[column2]=>'sand'
),
[1]=>array(
[column1]=>'2',
[column2]=>'clay'
)
)
[budget2]=>array(
[0]=>array(
[column1]=>'3',
[column2]=>'silt'
),
[1]=>array(
[column1]=>'4',
[column2]=>'stone'
)
)
So far I have been playing around with Yii's CdbCommand and CdbDataReader and PHP's PDOStatement but nothing is working right. I tried the following code
public function actionBidCostByBudget(){
$command = Yii::app()->db
->createCommand()
->Select('*')
->From('bid_cost')
# ->Query()
;
echo '<pre>';
echo get_class($command);
$pdostatement=$command->getPdoStatement();
if($pdostatement) echo get_class($pdostatement);
# print_r($statement->fetchall(PDO::FETCH_COLUMN|PDO::FETCH_GROUP));
# print_r($command->readall());
# print_r($statement->fetch());
# $columnsArray = BidCost::attributeLabels();
//print_r($rowsArray);
//$this->layout='\\layout';
}
The attempts to print_r all print out with nothing. getPdoStatement equals nothing. I have been trying to use PDO::FETCH_COLUMN|PDO::FETCH_GROUP as per the Php.net website, but it does not work either because I get nothing.
One of Yii's strengths is it's ActiveRecord, so why not use it?
Make your budget to a separate table (so you can generate a model from it). Reference it from your "datatable".
CREATE TABLE budget (
id INTEGER PRIMARY KEY,
name TEXT
);
CREATE TABLE datatable(
column1 TEXT,
column2 TEXT,
...
budget_id INTEGER,
FOREIGN KEY(budget_id) REFERENCES budget(id)
);
Next generate models with Gii, and now you can use your newly made relations like this:
$budget = Budget::model()->findByAttributes( ["name"=>"budget2"] );
foreach( $budget->datatables as $dt ) {
echo $dt->column1;
echo $dt->column2;
}
(I know. Not the array you asked for. Sorry if I'm way off with this.)
Alright, the bottom line is that I was not able to find a way to do this right thru Yii, so I did it with a more hands-on approach.
The first thing I did was basically initiate a database connection thru Yii.
$command = Yii::app()->db //outputs CDbConnnection
The next thing I did was get a PDO class from the connection:
$pdoinstance = $command->getPdoInstance(); //outputs PDO class
From this point, it was help obtained from PHP.net and another question posted on this forum:
$pdostatement=$pdoinstance->prepare('SELECT BUDGET_CODE,
PAY_ITEM, ITEM, DESCRIPTION FROM bidcost');
$pdostatement->execute();
//default fetch mode could not be set
# $pdostatement->setfetchmode(PDO::FETCH_GROUP|PDO::FETCH_ASSOC);
//returns array
$testarray=$pdostatement->fetchAll(PDO::FETCH_GROUP|PDO::FETCH_ASSOC);
I'm using readbeanphp as ORM for my php project. I'm trying to load a bean with an additional where clasue. But i'm not sure how to do this.
Normally i'd get a 'bean' like this:
$book = R::load('book', $id);
Which is basically like saying:
SELECT * FROM book WHERE id = '$id'
But i need to add another condition in the where clause:
SELECT * FROM book WHERE id = '$id' AND active = 1
How can i do this with redbeanphp?
R::find() and R::findOne() is what you are looking for:
$beans=R::find("books","active=? AND id=?",array(1,1));
Or if you want a single bean only:
$bean=R::findOne("books","active=? AND id=?",array(1,1));
R::find() will return multiple beans, while R::findOne() returns just a single bean.
You technically could use R::load() but would have to use PHP to check the active field after the bean is loaded to test if it is valid:
$bean=R::load("book",$id);
if($bean->active==1){//valid
//do stuff
}else{//not valid
//return error
}
Hope this helps!
RedBean_Facade::load is using for primary key only.
if you want get beans by a complex query
use
R::find like,
$needles = R::find('needle',' haystack = :haystack
ORDER BY :sortorder',
array( ':sortorder'=>$sortorder, ':haystack'=>$haystack ));
Read more about R::find
http://www.redbeanphp.com/manual/finding_beans
try to use getAll to write your query directly with parameters
R::getAll( 'select * from book where
id= :id AND active = :act',
array(':id'=>$id,':act' => 1) );
Read more about queries,
http://www.redbeanphp.com/manual/queries
these answers are fine but can be simplified. What you should use is:
$book = R::find('books', id =:id AND active =:active, array('id' => $id, 'active' => 1));
And then you can do your standard foreach to loop through the returned array of data.
I've Collective Intelligence book, but I'm not sure how it can be apply in practical.
Let say I have a PHP website with mySQL database. User can insert articles with title and content in the database. For the sake of simplicity, we just compare the title.
How to Make Coffee?
15 Things About Coffee.
The Big Question.
How to Sharpen A Pencil?
Guy Getting Hit in Balls
We open 'How to Make Coffee?' article and because there are similarity in words with the second and fourth title, they will be displayed in Related Article section.
How can I implement this using PHP and mySQL? It's ok if I have to use Python. Thanks in advance.
Store a set of keywords alongside each product, which should essentially be everything in the title besides a set of stop words. When a title is displayed, you find any other products which share keywords in common (with those with one or more in common given priority).
You could further enhance this by assigning a score to each keyword based on its scarcity (with more scarce words being given a higher score, as a match on 'PHP', for instance, is going to be more relevant than a match on 'programming'), or by tracking the number of times a user navigates manually between a set of products.
Regardless you'd best start off by making it simple, and then enhance it as you go on. Depending on the size of your database more advanced techniques may not be all that fruitful.
You're best off using a set of tags which are parsed and stored in the db when the title is inserted, and then querying based on that.
If you have to parse the title though, you'd basically be doing a LIKE query:
SELECT * FROM ENTRIES WHERE TITLE LIKE '%<keyword>%';
For a more verbose answer though:
// You need some test to see if the word is valid.
// "is" should not be considered a valid match.
// This is a simple one based on length, a
// "blacklist" would be better, but that's up to you.
function isValidEntry( $word )
{
return strlen( $word ) >= 4;
}
//to hold all relevant search strings:
$terms = array();
$postTitleWords = explode( ' ' , strtolower( 'How to Make Coffee' ) );
for( $postTitleWords as $index => $word )
{
if( isValidEntry( $word ) ) $terms[] = $word;
else
{
$bef = #$postTitleWords[ $index - 1 ];
if( $bef && !isValidEntry( $bef ) ) $terms[] = "$bef $word";
$aft = #$postTitleWords[ $index + 1 ];
if( $aft && !isValidEntry( $aft ) ) $terms[] = "$word $aft";
}
}
$terms = array_unique( $terms );
if( !count( $terms ) )
{
//This is a completely unique title!
}
$search = 'SELECT * FROM ENTRIES WHERE lower( TITLE ) LIKE \'%' . implode( '%\' OR lower( TITLE ) LIKE \'%' $terms ) . '\'%';
// either pump that through your mysql_search or PDO.
This can be simply achieved by using wildcards in SQL queries. If you have larger texts and the wildcard seems to be unable to capture the middle part of text then check if the substring of one matches the other. I hope this helps.
BTW, your question title asks about implementing recommendation system and the question description just asks about matching a field among database records. Recommendation system is a broad topic and comes with many interesting algorithms (e.g, Collaborative filtering, content-based method, matrix factorization, neural networks, etc.). Please feel free to explore these advanced topics if your project is to that scale.