I have a MySQL database with user inputted address's in it and need to sort and echo/print in order of the amount of times an address is used/displayed in the database? i.e if an address is in the database more times, then it is to be displayed first, and the least times is to be displayed last in a environment.
There is no example of coding at this stage, because it is a new script and not to sure where to start with it.
Could any one point me in the right direction?
This seams to have done the job!
$sqld="SELECT DeliveryName, DeliveryAddress, count(*)
AS alias
FROM rwxoq_jobs
GROUP BY DeliveryAddress
ORDER BY alias DESC";
$resultd = mysqli_query($conn, $sqld);
while($rowd = mysqli_fetch_assoc($resultd)) {
if (strpos($list, $rowd{'DeliveryAddress'}) === false) {
$list .= $rowd{'DeliveryAddress'}.'|';
echo $rowd{'DeliveryName'}.'<BR>'.$rowd{'DeliveryAddress'}.'<BR>';
}
}
Related
I've developed a bidding system with PHP and MySQL.
It works good in the most of the cases, but I've noticed there is a problem when offers are really close.
$now = DateTime::createFromFormat('U.u', microtime(true));
$dateMicroTime = date("Y-m-d H:i:s").".".$now->format("u");
$amountToRaise = 100;
$lastOffer = $bid->lastOffer();
//if there is an offer yet
if($lastOffer){
$newPrice = $lastOffer->getAmount()+$amountToRaise;
//else is the first offer
}else{
$newPrice = $amountToRaise;
}
//if the user is not the last bidder
if($user->getId() != $lastOffer->getUserId()){
$bidOffer = new BidOffer();
$bidOffer->setBidId($bid->getId());
$bidOffer->setUserId($user->getId());
$bidOffer->setAmount($newPrice);
$bidOffer->setTime($dateMicroTime);
$bidOffer->save();
//if this is not the first offer I give back the money to the previous user
if($lastOffer){
$lastUser = $lastOffer->user();
$lastUser->setCash($lastUser->getCash()+$lastOffer->getAmount());
$lastUser->save();
}
}
The code works well when offers are done in different moments, but users offer in the same seconds for example: 18:00:01.1299022 and 18:00.02.1222377
The user with previous offer doesn't receive back the offer.
How can I fix this? I've tried to use a temporary variable to block the statement temporary until every query are executed, but no success.
I would separate dateTime from microtime and would not use $dateMicroTime = date("Y-m-d H:i:s").".".$now->format("u");.
You can than use microtime to extract the last bidder. This can be done by adding a bid_utime column in your DB. If you are looking all the bidders for one auction chronologically ORDER BY table.bid_utime DESC.Last bidder can be found by ORDER BY table.bid_utime DESC LIMIT 1 as a return from $lastOffer = $bid->lastOffer();.
This also means you wont be saving your bids with: $bidOffer->setTime($dateMicroTime);but with something like:
$bidOffer->setDate($date); and $bidOffer->set_uTime($now);
But you can also skip all of this and return only the last entry from the bid table with SELECT * FROM bid_Table ORDER BY ID DESC LIMIT 1 and forget about dateMicroTime and microtime. Hope this helps.
I am currently taking an IT course in which people can bring in their computer(s) and the class works on them to get experience. Right now, the instructor has the customers fill out a sheet of paper giving their name, phone number and the computer's issue(s). However, he would like to use a PHP page to allow the students or himself look back to see what this person's previous issues were (if any). I am using PDO and prepared statements to query the database, but I am having trouble figuring out how to get the number of records returned by the prepared statement. I've tried using stmt_num_rows, but it doesn't appear to be working. Here is the code I have so far:
$custID = $_GET["id"];
$compID = $_GET["compID"];
$stmtIssues = $db->prepare("SELECT IssueID, DateRequested, Issue, ActionsTaken FROM ISSUES WHERE ComputerID=:compID AND CustomerID=:custID ORDER BY DateRequested");
$stmtIssues->bindParam(":custID", $custID);
$stmtIssues->bindParam(":compID", $compID);
$stmtIssues->execute();
$numIssues = stmt_num_rows($stmtIssues);
Am I doing this right?
Any and all help is greatly appreciated.
Chris
You could do a few things:
Solution one, if you just want the count, let the database count for you:
$stmtIssues = $db->prepare("SELECT COUNT(IssueID) FROM ISSUES WHERE ComputerID=:compID AND CustomerID=:custID ORDER BY DateRequested");
$stmtIssues->bindParam(":custID", $custID);
$stmtIssues->bindParam(":compID", $compID);
$stmtIssues->execute();
$numIssues = $stmtIssues->fetchColumn();
Solution two, if you're going to display the results in addition to the count:
$stmtIssues = $db->prepare("SELECT IssueID, DateRequested, Issue, ActionsTaken FROM ISSUES WHERE ComputerID=:compID AND CustomerID=:custID ORDER BY DateRequested");
$stmtIssues->bindParam(":custID", $custID);
$stmtIssues->bindParam(":compID", $compID);
$stmtIssues->execute();
$rows = $db->fetchAll();
$numIssues = count($rows);
foreach ($rows as $row) {
echo $row['IssueID']; // you can add other columns and/or formatting here too.
}
Solution one is quicker and returns only the count. Solution two, on the other hand, returns all details you may want to display.
I have a bunch of photos on a page and using jQuery UI's Sortable plugin, to allow for them to be reordered.
When my sortable function fires, it writes a new order sequence:
1030:0,1031:1,1032:2,1040:3,1033:4
Each item of the comma delimited string, consists of the photo ID and the order position, separated by a colon. When the user has completely finished their reordering, I'm posting this order sequence to a PHP page via AJAX, to store the changes in the database. Here's where I get into trouble.
I have no problem getting my script to work, but I'm pretty sure it's the incorrect way to achieve what I want, and will suffer hugely in performance and resources - I'm hoping somebody could advise me as to what would be the best approach.
This is my PHP script that deals with the sequence:
if ($sorted_order) {
$exploded_order = explode(',',$sorted_order);
foreach ($exploded_order as $order_part) {
$exploded_part = explode(':',$order_part);
$part_count = 0;
foreach ($exploded_part as $part) {
$part_count++;
if ($part_count == 1) {
$photo_id = $part;
} elseif ($part_count == 2) {
$order = $part;
}
$SQL = "UPDATE article_photos ";
$SQL .= "SET order_pos = :order_pos ";
$SQL .= "WHERE photo_id = :photo_id;";
... rest of PDO stuff ...
}
}
}
My concerns arise from the nested foreach functions and also running so many database updates. If a given sequence contained 150 items, would this script cry for help? If it will, how could I improve it?
** This is for an admin page, so it won't be heavily abused **
you can use one update, with some cleaver code like so:
create the array $data['order'] in the loop then:
$q = "UPDATE article_photos SET order_pos = (CASE photo_id ";
foreach($data['order'] as $sort => $id){
$q .= " WHEN {$id} THEN {$sort}";
}
$q .= " END ) WHERE photo_id IN (".implode(",",$data['order']).")";
a little clearer perhaps
UPDATE article_photos SET order_pos = (CASE photo_id
WHEN id = 1 THEN 999
WHEN id = 2 THEN 1000
WHEN id = 3 THEN 1001
END)
WHERE photo_id IN (1,2,3)
i use this approach for exactly what your doing, updating sort orders
No need for the second foreach: you know it's going to be two parts if your data passes validation (I'm assuming you validated this. If not: you should =) so just do:
if (count($exploded_part) == 2) {
$id = $exploded_part[0];
$seq = $exploded_part[1];
/* rest of code */
} else {
/* error - data does not conform despite validation */
}
As for update hammering: do your DB updates in a transaction. Your db will queue the ops, but not commit them to the main DB until you commit the transaction, at which point it'll happily do the update "for real" at lightning speed.
I suggest making your script even simplier and changing names of the variables, so the code would be way more readable.
$parts = explode(',',$sorted_order);
foreach ($parts as $part) {
list($id, $position) = explode(':',$order_part);
//Now you can work with $id and $position ;
}
More info about list: http://php.net/manual/en/function.list.php
Also, about performance and your data structure:
The way you store your data is not perfect. But that way you will not suffer any performance issues, that way you need to send less data, less overhead overall.
However the drawback of your data structure is that most probably you will be unable to establish relationships between tables and make joins or alter table structure in a correct way.
I'm really new to PHP but I've been learning all I can, but I'm also aware that I have a lot to learn so go easy on me.
I'm currently working on a classifieds script and although the code is severely dated, It was a lot worse before I began cleaning it up and now I'm just trying to get the classifieds stable again, then I plan on going back and updating things to a more modern language (PDO) but for now I have NO IDEA on where to begin (and don't want to be reading for months while getting nowhere as I have been while learning HTML, CSS, PHP and JS)
The code below originally displayed the Title column from the table it was fetching the data from (tt_%s) but I have since modified the form which inserts the data into the DB so now there is no longer a "Title" column and in it's place there is now Year and Model from one table and Manufacturer from another table but this is where I get confused and am asking for help.
Presently this is what I am looking at; (Below the code I'll explain more)
<?php
echo "<div class='mostPopular'>";
echo "Popular<br>Listings";
$node = new sqlNode();
$node->table = "types";
$node->select = "ID";
$node->orderby = "ORDER BY rand()";
if(($typeRS = $mysql->select($node)) === false )
die('Unable to Retrieve Ad Type');
$sql = array();
$typeID = 0;
while( $adType = mysql_fetch_assoc($typeRS) ){
$typeID = sprintf("`tt_%s`", abs(intval($adType['ID'])));
$sql[] = sprintf("SELECT %s.Year, %s.Hits, %s.CategoryID, %s.ID, CONCAT('','%s') AS TypeID FROM %s WHERE (`ExpireDate` > NOW()) ",
$typeID,
$typeID,
$typeID,
$typeID,
intval($adType['ID']),
$typeID);
}
$sqlStr = #implode("union ",$sql);
$sqlStr .= " ORDER BY Hits DESC LIMIT 5";
if(($adRS = $mysql->exSql($sqlStr)) === false)
die('Unable to Retrieve Most Popular Ads');
while( $ad = mysql_fetch_assoc($adRS) ){
echo "<p>";
echo "<a href='detail.php?fatherID=".$ad['CategoryID']."&TypeID=".$ad['TypeID']."&ListingID=".$ad['ID']."'>";
echo $ad['Title'];
echo "</a>";
echo "</p>";
}
echo "</div>";
?>
For starters, I don't know what CONCAT('','%s') is all about, nor do I know what $sqlStr = #implode("union ",$sql); is all about.
In addition to these issues, considering that this code is outdated and I should be switching to PDO, I was hoping someone could show me exactly how to perform these queries with PDO as then I could learn by example and apply the same procedures to other queries throughout the site.
If anyone wouldn't mind conversing with me to the point where I can perform the same outcome with PDO I'd be most appreciative and I thank you all in advance while I eagerly await your replies.
BTW, I ask this after studying every PHP and MySql tutorial I can find for the past several months
Thanks
Although "Please rewrite this code to PDO" being too localized one, the real problem you have require different solution.
First of all, you need to fix your database architecture. It's terrible.
Premature optimization, being the root of all evil, depraved you from the right ways. There is no point in splitting your data into small chunks if you going to union them anyway.
You have to have one table for the ads.
It will make all this code obsolete, leaving only one regular query which can be run in one conventional PDO call.
Next, this code has been written by some sprintf() maniac, who made it overcomplicated out of nowhere. As a matter of fact, not a single sprintf() is really needed here.
$sql = array();
while( $row = mysql_fetch_assoc($typeRS) ){
$typeID = abs($row['ID']);
$sql[] = "SELECT Year, Hits, CategoryID, ID, '$typeID' AS TypeID
FROM tt_$typeID WHERE ExpireDate > NOW()";
}
$sqlStr = implode("union ",$sql)." ORDER BY Hits DESC LIMIT 5"
is enough.
But again, no need for this union query. Everything have to be performed via single ordinary query like this one
SELECT Year, Hits, CategoryID, ID, TypeID FROM ads ORDER BY Hits DESC LIMIT 5
which you no doubt will be able to run using whatever PDO example you have
i've got a script which is supposed to run through a mysql database and preform a certain 'test'on the cases. Simplified the database contains records which represent trips that have been made by persons. Each record is a singel trip. But I want to use only roundway trips. So I need to search the database and match two trips to each other; the trip to and the trip from a certain location.
The script is working fine. The problem is that the database contains more then 600.000 cases. I know this should be avoided if possible. But for the purpose of this script and the use of the database records later on, everything has to stick together.
Executing the script takes hours right now, when executing on my iMac using MAMP. Off course I made sure that it can use a lot of memory etcetare.
My question is how could I speed things up, what's the best approach to do this?
Here's the script I have right now:
$table = $_GET['table'];
$output = '';
//Select all cases that has not been marked as invalid in previous test
$query = "SELECT persid, ritid, vertpc, aankpc, jaar, maand, dag FROM MON.$table WHERE reasonInvalid != '1' OR reasonInvalid IS NULL";
$result = mysql_query($query)or die($output .= mysql_error());
$totalCountValid = '';
$totalCountInvalid = '';
$totalCount = '';
//For each record:
while($row = mysql_fetch_array($result)){
$totalCount += 1;
//Do another query, get all the rows for this persons ID and that share postal codes. Postal codes revert between the two trips
$persid = $row['persid'];
$ritid = $row['ritid'];
$pcD = $row['vertpc'];
$pcA = $row['aankpc'];
$jaar = $row['jaar'];
$maand = $row['maand'];
$dag = $row['dag'];
$thecountquery = "SELECT * FROM MON.$table WHERE persid=$persid AND vertpc=$pcA AND aankpc=$pcD AND jaar = $jaar AND maand = $maand AND dag = $dag";
$thecount = mysql_num_rows(mysql_query($thecountquery));
if($thecount >= 1){
//No worries, this person ID has multiple trips attached
$totalCountValid += 1;
}else{
//Ow my, the case is invalid!
$totalCountInvalid += 1;
//Call the markInvalid from functions.php
$totalCountValid += 1;
markInvalid($table, '2', 'ritid', $ritid);
}
}
//Echo the result
$output .= 'Total cases: '.$totalCount.'<br>Valid: '.$totalCountValid.'<br>Invalid: '.$totalCountInvalid; echo $output;
Your basic problem is that you are doing the following.
1) Getting all cases that haven't been marked as invalid.
2) Looping through the cases obtained in step 1).
What you can easily do is to combine the queries written for 1) and 2) in a single query and loop over the data. This will speed up the things a bit.
Also bear in mind the following tips.
1) Selecting all columns is not at all a good thing to do. It takes ample amount of time for the data to traverse over the network. I would recommend replacing the wild-card with all columns that you really need.
SELECT * <ALL_COlumns>
2) Use indexes - sparingly, efficiently and appropriately. Understand when to use them and when not to.
3) Use views if you can.
4) Enable MySQL slow query log to understand which queries you need to work on and optimize.
log_slow_queries = /var/log/mysql/mysql-slow.log
long_query_time = 1
log-queries-not-using-indexes
5) Use correct MySQL field types and the storage engine (Very very important)
6) Use EXPLAIN to analyze your query - EXPLAIN is a useful command in MySQL which can provide you some great details about how a query is ran, what index is used, how many rows it needs to check through and if it needs to do file sorts, temporary tables and other nasty things you want to avoid.
Good luck.