So basically i'm trying to create a complex timetable and i have these two methods that each perform a different check function for me:
Checks if i have a unique array
function tutorAllot($array,$check,$period){
//check for clashes and return non colliding allotment
shuffle($array);
$rKey = array_rand($array);
if(array_key_exists($array[$rKey]['teacher_id'], $check[$period])) {
return $this->tutorAllot($array,$check,$period);
}
return $tutor = array($array[$rKey]['teacher_id'] => $array[$rKey]['subject_code']);
}
checks that each subject does not appear more than twice in a day
function checkDayLimit($data,$check){
//check double day limit
$max = 2;
$value = array_values($check);
$tempCount = array_count_values($data);
return (array_key_exists($value[0], $tempCount) && $tempCount[$value[0]] <= $max) ? true : false;
}
I'm calling the functions from a loop and populating timetable array only if all conditions area satisfied:
$outerClass = array();
foreach ($value as $ky => $val) {
$innerClass = array(); $dayCount = array();
foreach ($periods[0] as $period => $periodData) {
$innerClass[$period] = array();
if(!($periodData == 'break')){
$return = $this->Schedule->tutorAllot($val,$clashCheck,$period);
if($return){
//check that the returned allocation hasnt reached day limit
if($this->Schedule->checkDayLimit($dayCount,$return)){
$innerClass[$period] += $return;
$clashCheck[$period] += $return;
}else{
}
}
}else{
$innerClass[$period] = '';
}
}
//debug($innerClass);
$outerClass[$ky] = $innerClass;
}
My requirements
If the checkDayLimit returns false , i want to go back and call tutorAllot function again to pick a new value.
I need to do this without breaking the loop.
I was thinking maybe i could use goto statement but only when am out of options.
Is there a way i can achieve this without using goto statement.
PHP v5.5.3 Ubuntu
Your architecture seems overly complex. Instead of
pick at random >> check limit >> if at limit, go to re-pick...
Why not incorporate both checks into a single function? It would
Filter out data that is not eligible to be picked, and return an array of legitimate choices
Pick at random from the safe choices and return the pick
addendum 1
I don't think there is any need for recursion. I would use array_filter to pass the data through a function that returns true for eligible members and false for the rest. I would then take the result of array_map and make a random selection from it
Related
I run a script under xampp with a mysqlDB.
I check if a domainname has an ip.
The problem is, that I have to check over 100000 domain names from a MySQL_DB.
The function "gethostbyname" works great, but my solution is too slow.
while($row = mysqli_fetch_array($db_res)) { // get the DB domainnames entrys
if (empty($row['status'])) {
$items[] = $row['domainnames'];
}
foreach ($items AS $domain) {
if ( gethostbyname($domain) != $domain ) {
do somthing.....
}
}
}
How do I get it faster?
Your foreach() loop inside of your while() loop is simply a bad idea. Think about it.
As you iterate the result set, $items swells and swells -- this means that the foreach() will have to work longer and longer and longer.
Ultimately, if you need to process the gethostbyname() value for the next task in your script, you should be storing that value at the same time that you INSERT the entry into your table the first time -- perhaps the new column can be host.
The smart money is not to call gethostbyname() 100000 times; have the value ready when you SELECT it.
Beyond the above logic, I don't see the need to declare an array with a single element/string, then iterate it.
In fact, your query should contain a WHERE clause that excludes rows that have a null/0/blank status value AND includes rows that have a host (new column) value that matches $domain so that php doesn't have to bother any qualifying/disqualifying conditions.
foreach ($db_res as $row) { // yes, you can simply iterate the result object
// do whatever with the associative string elements (e.g. $row['domainnames'])
// ...you know this is a string and not an array, right? -^^^^^^^^^^^^^^^^^^^
}
thanks for the answers.
With your assistance i was able to reduce the procedure to:
while($row = mysqli_fetch_array($db_res))
{
$domain = $row['domainnames'];
if ( gethostbyname($domain) != $domain ) {
do somthing.....;
}
else{
do somthing.....;
}
}
it feels a little bit faster but not enough.
#mickmackusa i catch now only the empty "status" fields:
$db_res = mysqli_query ($db_link, "select domainnames FROM domaintable WHERE status = ''")
Looks like when your while loop iterates, it uses the $items from the last iteration - which will waste time - so please try this version (putting the foreach into the if:
while($row = mysqli_fetch_array($db_res)) { // get the DB domainnames entrys
if (empty($row['status'])) {
$items[] = $row['domainnames'];
foreach ($items AS $domain) {
if ( gethostbyname($domain) != $domain ) {
do somthing.....
}
}
}
}
I have a 2 dimensional array. Each subarray consists out of a number of options. I am trying to write a script which picks one of these options for each row. The chosen options have to be unique. An example:
$array = array(
1 => array(3,1),
2 => array(3),
3 => array(1,5,3),
);
With a solution:
$array = array(
1 => 1,
2 => 3,
3 => 5,
);
I have finished the script, but i am not sure if it is correct. This is my script. The description of what i am doing is in the comments.
function pickUnique($array){
//Count how many times each option appears
$counts = array();
foreach($array AS $options){
if(is_array($options)){
foreach($options AS $value){
//Add count
$counts[$value] = (isset($counts[$value]) ? $counts[$value]+1 : 1);
}
}
}
asort($counts);
$didChange = false;
foreach($counts AS $value => $count){
//Check one possible value, starting with the ones that appear the least amount of times
$key = null;
$scoreMin = null;
//Search each row with the value in it. Pick the row which has the lowest amount of other options
foreach($array AS $array_key => $array_options){
if(is_array($array_options)){
if(in_array($value,$array_options)){
//Get score
$score = 0;
$score = count($array_options)-1;
if($scoreMin === null OR ($score < $scoreMin)){
//Store row with lowest amount of other options
$scoreMin = $score;
$key = $array_key;
}
}
}
}
if($key !== null){
//Store that we changed something while running this function
$didChange = true;
//Change to count array. This holds how many times each value appears.
foreach($array[$key] AS $delValue){
$counts[$delValue]--;
}
//Remove chosen value from other arrays
foreach($array AS $rowKey => $options){
if(is_array($options)){
if(in_array($value,$options)){
unset($array[$rowKey][array_search($value,$options)]);
}
}
}
//Set value
$array[$key] = $value;
}
}
//validate, check if every row is an integer
$success = true;
foreach($array AS $row){
if(is_array($row)){
$success = false;
break;
}
}
if(!$success AND $didChange){
//Not done, but we made changes this run so lets try again
$array = pickUnique($array);
}elseif(!$success){
//Not done and nothing happened this function run, give up.
return null;
}else{
//Done
return $array;
}
}
My main problem is is that i have no way to verify if this is correct. Next to that i also am quite sure this problem has been solved a lot of times, but i cannot seem to find it. The only way i can verificate this (as far as i know) is by running the code a lot of times for random arrays and stopping when it encounters an insolvable array. Then i check that manually. So far the results are good, but this way of verication is ofcourse not correct.
I hope somebody can help me, either with the solution, the name of the problem or the verification method.
I know how to get a mysql-row and convert it to json:
$row = mysqli_fetch_assoc(mysqli_query($db, "SELECT * FROM table WHERE id=1"));
echo json_encode($row); // it's an ajax-call
but:
the db-row has different types like int, float, string.
by converting it using json_encode() all results are strings.
Is there a better way to correct the types than this:
$row['floatvalue1'] = 0+$row['floatvalue1'];
$row['floatvalue2'] = 0+$row['floatvalue2'];
$row['intvalue1'] = 0+$row['intvalue1'];
I would like to loop through the keys and add 0 because:
first coding rule: DRY - dont repeat yourself
but i can't because:
row has also other types than numbers (string, date)
there are many columns
design is in dev, so columns-names often changes
Thanks in advance and excuse my bad english :-)
EDIT (to answer the comment-question from Casimir et Hippolyte):
I call this php-code using ajax to get dynamically sql-values. in my javascript-code i use the results like this:
result['intvalue1'] += 100;
lets say the json-result of intval1 is 50, the calculated result is:
"50100", not 150
The code below is just a proof of concept. It needs encapsulation in a function/method and some polishing before using it in production (f.e. call mysqli_fetch_field() in a loop and store the objects it returns before processing any row, not once for every row).
It uses the function mysqli_fetch_field() to get information about each column of the result set and converts to numbers those columns that have numeric types. The values of MYSQLI_TYPE_* constants can be found in the documentation page of Mysqli predefined constants.
// Get the data
$result = mysqli_query($db, "SELECT * FROM table WHERE id=1");
$row = mysqli_fetch_assoc($result);
// Fix the types
$fixed = array();
foreach ($row as $key => $value) {
$info = mysqli_fetch_field($result);
if (in_array($info->type, array(
MYSQLI_TYPE_TINY, MYSQLI_TYPE_SHORT, MYSQLI_TYPE_INT24,
MYSQLI_TYPE_LONG, MYSQLI_TYPE_LONGLONG,
MYSQLI_TYPE_DECIMAL,
MYSQLI_TYPE_FLOAT, MYSQLI_TYPE_DOUBLE
))) {
$fixed[$key] = 0 + $value;
} else {
$fixed[$key] = $value;
}
}
// Compare the results
echo('all strings: '.json_encode($row)."\n");
echo('fixed types: '.json_encode($fixed)."\n");
something like
$row['floatvalue1'] = reset( sscanf ( $row['floatvalue1'] , "%f" ));
$row['floatvalue2'] = reset( sscanf ( $row['floatvalue2'] , "%f" ));
$row['intvalue1'] = reset( sscanf ( $row['intvalue1'] , "%d" ));
json_encode($row);
If you're simply trying to make sure that your values are operable with respect to their type, you need to first cast their type correctly.
Unless you need them server-side, I would just pass-on the json directly to the front-end and do the work there.
In Javascript, you could make an attempt at casting the numbers like so:
function tryNumber(string){
return !isNaN( parseInt(string) ) ? parseInt(string) : string;
}
function tryDate(string){
return !isNaN( new Date(string).getTime() ) ? new Date(string) : string;
}
tryNumber('foo'); // "hello"
tryNumber('24'); // 24
tryDate('bar'); // "bar"
tryDate('December 17, 1995'); // "Sun Dec 17 1995 00:00:00 GMT+0000 (GMT)"
These two lines attempt to cast the values as a Date/Number. If they can't be cast, they will remain String's.
A MySQLi OO version based on #axiac's answer, that produces a JSON array ($jsnAll) containing all records. In this code snippet, the method FixSQLType is called to fix a row. Note, it should be wrapped in a try{}catch{} block and "objMySQLi" has already been instantiated:
$lcAllRows = array();
// Make an SQL SELECT statement
$SQL = "SELECT * FROM $lcName WHERE $lcWhere";
// Run the query
$this->sqlResult = $this->objMySQLi->query($SQL);
// Fetch the result
while( $row = $this->sqlResult->fetch_assoc()){
$lcCount = count($lcAllRows) ;
// Call to fix, row
$fixedRow = $this->FixSQLType($row);
$lcAllRows[$lcCount]= $fixedRow;
}
$jsnAll = json_encode($lcAllRows);
The FixSQLType method. This is almost identical to #axiac's answer, except for the call to $this->sqlResult->fetch_field_direct($i). "fetch_field" seemed to get itself lost, using "fetch_field_direct" overcame that problem.
private function FixSQLType($pRow){
// FROM https://stackoverflow.com/a/28261996/7571029
// Fix the types
$fixed = array();
$i = 0;
foreach ($pRow as $key => $value) {
$info = $this->sqlResult->fetch_field_direct($i);
$i++;
if (in_array($info->type, array(
MYSQLI_TYPE_TINY, MYSQLI_TYPE_SHORT, MYSQLI_TYPE_INT24,
MYSQLI_TYPE_LONG, MYSQLI_TYPE_LONGLONG,
MYSQLI_TYPE_DECIMAL,
MYSQLI_TYPE_FLOAT, MYSQLI_TYPE_DOUBLE
))) {
$fixed[$key] = 0 + $value;
} else {
$fixed[$key] = $value;
}
}
return $fixed;
}
My goal is to iterate over all rows in a specific ColumnFamily in a node.
Here is the php code (using my wrapper over phpcassa):
$ring = $cass_db->describe_ring();
foreach ($ring as $ring_details)
{
$start_token = $ring_details->start_token;
$end_token = $ring_details->end_token;
if ($start_token != null && $end_token != null)
{
$i = 0;
$batch_size = 10;
$params = array(
'token_start' => $start_token,
'token_finish' => $end_token,
'row_count' => $batch_size,
'buffer_size' => 1000
);
while ($batch = $cass_db->get_range_by_token('myColumnFamily', $params))
{
var_dump('Batch# '.$i);
foreach ($batch as $row)
{
$row_key = $row[0];
$row_values = $row[1];
var_dump($row_key);
}
$i++;
//Just to stop infinite loop
if ($i > 14)
{
die();
}
}
}
}
get_range_by_token() uses default parameters overwritten by $params.
In each batch I get the same 10 row keys.
How to iterate over all existing rows in a large Cassandra DB?
I am not a PHP developer so I may misunderstand something in your code. More, you did not specify which cassandra version you are using.
Iteration on all rows is generally done starting and ending with an empty token, and redefining the start token in each iteration. In your code I can't see where you redefine token_start in each iteration. If you don't redefine it you're querying cassandra everytime for the same range of tokens and you will get always the same resultset.
Your code should do something like this ...
start_token = '';
end_token = '';
page_size = 100;
while ( get_range_by_token('cf', start_token, end_token, page_size) {
// here I should get page_size rows (unless I'm in last iteration or table rows is smaller than page_size elements)
start_token = rows[rows.size()].getKey();
}
HTH,
Carlo
I am building up an array with a set of database fields with information about table, actual field name and descriptive field name as a multi-dimensional array. Here is what it currently looks like:
$Fields['User']['ID'] = "User ID";
$Fields['User']['FirstName'] = "First Name";
$Fields['Stats']['FavouriteOrder'] = "Favourite Item Ordered";
$Fields['Geographic']['Location'] = "Current Location";
$Fields['Geographic']['LocationCode'] = "Current Location Code";
Okay, this is fine, but I am piping this into a system that allows exporting of selected fields, and in the end I want to foreach() through the different levels, extract the data and then ultimately have all the descriptive fields to be displayed sorted alphabetically using their descriptive name. So ultimately in the order: Current Location, Current Location Code, Favorite Item Ordered, First Name then User ID - obviously keeping index associations.
I can't use usort() and I can't use array_multisort()... or maybe I can and I just don't know how. usort() seems to need a key to sort by, but I have variable keys. array_multisort() just seems to do the same as sort() really.
This is for a 2D array only. Not the most elegant piece of code I've written, but it works...
foreach($Fields as $key=>$var) {
ksort($var);
$Fields[$key]=$var;
}
ksort($Fields);
Let me rather give a real-life data example, as opposed to fake data because the fake data nearly confused me. So, fake data is commented.
/*
$Fields['User']['ID'] = "User ID";
$Fields['User']['FirstName'] = "First Name";
$Fields['Stats']['FavouriteOrder'] = "Favourite Item Ordered";
$Fields['Geographic']['Location'] = "Current Location";
$Fields['Geographic']['LocationCode'] = "Current Location Code";
*/
$Fields['Product']['ReferenceNumber'] = "Product Reference Number";
$Fields['Product']['Halaal'] = "Halaal Status";
$Fields['Product']['Kosher'] = "Kosher Status";
$Fields['Product']['KosherType'] = "Kosher Type";
$Fields['Product']['CuringSalts'] = "Curing Salts Status";
$Fields['Product']['ProductVisibility'] = "Product Visibility";
$Fields['Product']['ProductStatus'] = "Product Status";
$Fields['Product']['PackBarCode'] = "Barcode";
$Fields['Product']['ProductDescription'] = "Product Description";
$Fields['Pack']['PackSize'] = "Pack Size";
$Fields['Pack']['PackSizeNumeric'] = "Numeric Pack Size";
$Fields['Allergens']['ContainsNuts'] = "Product Contains Nuts";
foreach ($Fields as $key => $value) {
ksort($value);
$Fields[$key] = $value;
}
ksort($Fields);
I'm having one of 'those' Fridays... print_r($Fields) reveals that the keys are being sorted and values are associated, but it's still sorting by the keys and not the end value.
It's almost like i need a reverse sorting system which checks all values first, sorts them and then says 'okay where do you belong ... ah you belong to FieldX in Table Y'
I was hoping there was a sneaky clever way to do it, perhaps there is, but I guess I'll write a function to parse through the data, write a reversed array and then re-write the original in value-order. Hectically inefficient, but it'll do.
Still open to better suggestions though!
I literally had to work this out yesterday for a project I was working on - here's my code:
Resource array looks like this:
$resource[$count]['title']
$resource[$count]['filepath']
$resource[$count]['filename']
$resource[$count]['taxonomy'][0]
A couple of sort functions to sort by title ASC or DESC
function compare_asc($a, $b) {
return strcmp($a['title'], $b['title']);
}
function compare_desc($a, $b) {
if ($a['title'] == $b['title']) {
return 0;
}
return ($a['title'] > $b['title']) ? -1 : 1;
//return strcmp($a['title'], $b['title']);
}
And finally use usort to do the dirty before you loop through $resource and output whatever it is you need.
usort($resource, "compare_asc");
Okay, it's not elegant at all. So I don't encourage using this and will look for a better way down the line. But here's the solution I've got that works with the examples above and below.
Unfortunately, the way I want it to be, the array HAS to contain a preceding 'ordering' number so, I suppose it's a fail on my part from the very beginning. But it works now.
$TempDescArray = array();
$TempFieldArray = array();
$TempTableArray = array();
$Pointer = 0;
foreach ($Fields as $Table => $FieldsArray) {
foreach ($FieldsArray as $Field => $Description) {
$TempDescArray[$Pointer] = $Description;
$TempFieldArray[$Pointer] = $Field;
$TempTableArray[$Pointer] = $Table;
$Pointer++;
}
}
asort($TempDescArray);
$Fields = array();
$Pointer2 = 0;
foreach ($TempDescArray as $Pointer => $Description) {
$Fields[$Pointer2][$TempTableArray[$Pointer]][$TempFieldArray[$Pointer]] = $Description;
$Pointer2++;
}