I'm in a bit of pickle but the answer is probably pretty simple.
So I have my POST variable:
Array ( [accept] => accept,29 [accept1] => accept,30 [submit] => Save Selections )
That's just a print_r of $_POST.
Basically what I want to do is get the first variable, remove the 'accept,' part and store the number next to it in a variable, run some MySQL queries using that variable (containing that number) then move onto the next one; removing the 'accept,' storing the number next to it and running a query using that stored number. It want to do this for as many times is necessary to go through all the elements containing 'accept,' then a number.
Any help would be appreciated.
I was playing around with some ideas and have this code. It obviously doesn't work but perhaps I could fix and build on it?
while($i <= $elements)
{
while($x == 1)
{
$id = explode(',', next($_POST));
echo $id;
$x = 0;
}
$i++;
}
Im not sure this would fix your problem but I hope this helps and gives you an idea:
$i = 0;
while($i <= count($your_array))
{
$your_var = substr($your_array[$i], 7, 2); //get the number from your accept,29
$query = "SELECT * FROM TABLE WHERE COLUMN = ". $your_var; //use it to run queries as you said
$i+=1;
}
UPDATE - Im not sure if this would work
foreach($your_post_array as $items)
{
$your_var = substr($items, 7, 2);
$query = "SELECT * FROM TABLE WHERE COLUMN = ". $your_var; //use it to run queries as you said
$i+=1;
}
Maybe you should try to echo first the variables to make sure echo $your_var = substr($items, 7, 2);
I would use a foreach loop to loop through $_POST, check if the key starts with accept (stripos?), explode the value if it does and get the second value of the found array and store that somewhere for later use.
By the way, if possible I would change the front-end so that you have just one variable (an array) in $_POST you have to loop through.
Related
I have a site were the user fills a form and all data is stored in a database, when the user enter his/hers page all the added data is visible. Today I´m doing this but in a lot of code rows and there is for sure a much smoother way to do this.
Here´s a look of how I have done it today:
$query = mysqli_query($dbhandle, "SELECT * FROM ..."); // ... added now
$row = mysqli_fetch_assoc($query);
$m0 = $row['m1'];
$m1 = $row['m2'];
$m2 = $row['m3'];
$m3 = $row['m4'];
...
$m47 = $row['m48'];
$firstPlace = $row['firstPlace '];
$secondPlace = $row['secondPlace '];
$thirdPlace = $row['thirdPlace '];
$fourthPlace= $row['fourthPlace'];
As you can see there are a lot of rows of code. What I would like to do is to loop through my query and then add the right value in the database to the right value in the form.
Appreciate help.
There definitely are many alternative (and in every possible sense of the word) better ways to go about your business.
For a kickoff: ask yourself what an array actually is. An array is a collection of data. You store them together because one value of that array in itself doesn't mean much. The data in an array belongs together. Why then, assign it to individual variables in the first place?
Of course, your $row array has keys like $row['m1'], which you assign to a variable called $m0. so the names of the fields in the database don't quite match the names your code uses. That's something that you can, quite easily, fix by changing your query: use aliasses for those fields:
SELECT m1 as m0, ... FROM
Now your array will have a key called m0, instead of m1. This reduces the rest of your code down to:
$row = mysqli_fetch_assoc($query);
echo 'M0: ', $row['m0'];//<-- use m0 value here.
Alternatively, you could use a second array that maps these field-names to the name you want to use in your code:
$map = array(
'm0' => 'm1'
);
echo 'M0: ', $row[$map['m0']];//use value of m0, which is the actual key if the $row array
Still, if you are hell-bound on unmaintainable, messy, error-prone and just awful code, you could use variable variables:
foreach ($row as $key => $value)
{
$$key = $val;
}
Note the double $ in $$key. This is like saying "the variable that is called whatever the value of $key is". If $key is firstname, the code above evaluates to $firstname = $value. But whatever you do: forget this is possible. It's like an enema: yes, it's possible, but you don't want one if you can avoid it. And in this case, you clearly can avoid it.
Loop through the $row var grabbing the key and value. If key starts with "m" followed by a 1 or 2 digit number, get the number, subtract one, concatenate it with "m", and assign the value. Otherwise just interpolate key into variable name and assign value.
foreach ( $row as $key => $value ) {
if ( preg_match('/^m(\d{1,2})/', $key, $matches) ) {
${'m' . ($matches[1] - 1)} = $value;
}
else { $$key = $value; }
}
In the above example, $row['m1'] value gets assigned to var $m0, and $row['firstPlace'] to var $firstPlace, etc.
I have to identify unsaved value from mysql table using php and mysql, for example i using table named as numtab and i have already stored some numbers 1, 3, 4, 7, 23, 12, 45 in numb column.
now i have generated one new number randomly(for example 23) and i have to check this number with already stored numbers,
if 23 is exist in the table mean i have to generate another one new number and have to check once again with stored values, this process have to continue till finding unsaved number.
if generated value is not exist in table mean can stop the process and can store this number in table.
here below the format i am currently using
$numb=23;
$qryb="select * from numtab where numb='$numb'";
$results=mysql_query($qryb)or die("ERROR!!");
if(mysql_num_rows($results) == 1)
{
$numb=rand(1,100);
mysql_query("insert query");
}
the problem is above the code is validation once only, its not verifying second time. i think if using for or while loop mean can solve this problem, but i dont know how to do looping, so help me to solve this problem.
You can use in clause like this :
$qryb="select * from numtab where numb in('$numb')";
$results=mysql_query($qryb)or die("ERROR!!");
$count = mysql_num_rows($results);
if ($count > 0) {
echo "number exist in db";
} else {
echo "number does not exist in db";
}
You could make a while() loop to check if the numbers exist in your database. You could also retrieve all numbers from the database, store them in an array and check if the generated number exists within that array.
The first option would be something like this:
do {
$numb=rand(1,100);
$qryb="select * from numtab where numb='$numb'";
$results = mysql_query($qryb) or die("ERROR!!");
} while(mysql_num_rows($results) >= 1)
mysql_query("insert query");
The second option would be something like this:
$query = mysql_query("SELECT DISTINCT(numb) as numb FROM numtab");
// set array
$array = array();
// look through query
while($row = mysql_fetch_assoc($query)){
// add each row returned into an array
$array[] = $row['numb'];
}
do
{
$numb = rand(1,100);
}
while(!in_array ( $numb , $array) ;
mysql_query("insert query");
I previously designed the website I'm working on so that I'd just query the database for the information I needed per-page, but after implementing a feature that required every cell from every table on every page (oh boy), I realized for optimization purposes I should combine it into a single large database query and throw each table into an array, thus cutting down on SQL calls.
The problem comes in where I want this array to include skipped IDs (primary key) in the database. I'll try and avoid having missing rows/IDs of course, but I won't be managing this data and I want the system to be smart enough to account for any problems like this.
My method starts off simple enough:
//Run query
$localityResult = mysql_query("SELECT id,name FROM localities");
$localityMax = mysql_fetch_array(mysql_query("SELECT max(id) FROM localities"));
$localityMax = $localityMax[0];
//Assign table to array
for ($i=1;$i<$localityMax+1;$i++)
{
$row = mysql_fetch_assoc($localityResult);
$localityData["id"][$i] = $row["id"];
$localityData["name"][$i] = $row["name"];
}
//Output
for ($i=1;$i<$localityMax+1;$i++)
{
echo $i.". ";
echo $localityData["id"][$i]." - ";
echo $localityData["name"][$i];
echo "<br />\n";
}
Two notes:
Yes, I should probably move that $localityMax check to a PHP loop.
I'm intentionally skipping the first array key.
The problem here is that any missed key in the database isn't accounted for, so it ends up outputting like this (sample table):
1 - Tok
2 - Juneau
3 - Anchorage
4 - Nashville
7 - Chattanooga
8 - Memphis
-
-
I want to write "Error" or NULL or something when the row isn't found, then continue on without interrupting things. I've found I can check if $i is less than $row[$i] to see if the row was skipped, but I'm not sure how to correct it at that point.
I can provide more information or a sample database dump if needed. I've just been stuck on this problem for hours and hours, nothing I've tried is working. I would really appreciate your assistance, and general feedback if I'm making any terrible mistakes. Thank you!
Edit: I've solved it! First, iterate through the array to set a NULL value or "Error" message. Then, in the assignations, set $i to $row["id"] right after the mysql_fetch_assoc() call. The full code looks like this:
//Run query
$localityResult = mysql_query("SELECT id,name FROM localities");
$localityMax = mysql_fetch_array(mysql_query("SELECT max(id) FROM localities"));
$localityMax = $localityMax[0];
//Reset
for ($i=1;$i<$localityMax+1;$i++)
{
$localityData["id"][$i] = NULL;
$localityData["name"][$i] = "Error";
}
//Assign table to array
for ($i=1;$i<$localityMax+1;$i++)
{
$row = mysql_fetch_assoc($localityResult);
$i = $row["id"];
$localityData["id"][$i] = $row["id"];
$localityData["name"][$i] = $row["name"];
}
//Output
for ($i=1;$i<$localityMax+1;$i++)
{
echo $i.". ";
echo $localityData["id"][$i]." - ";
echo $localityData["name"][$i];
echo "<br />\n";
}
Thanks for the help all!
Primary keys must be unique in MySQL, so you would get a maximum of one possible blank ID since MySQL would not allow duplicate data to be inserted.
If you were working with a column that is not a primary or unique key, your query would need to be the only thing that would change:
SELECT id, name FROM localities WHERE id != "";
or
SELECT id, name FROM localities WHERE NOT ISNULL(id);
EDIT: Created a new answer based on clarification from OP.
If you have a numeric sequence that you want to keep unbroken, and there may be missing rows from the database table, you can use the following (simple) code to give you what you need. Using the same method, your $i = ... could actually be set to the first ID in the sequence from the DB if you don't want to start at ID: 1.
$result = mysql_query('SELECT id, name FROM localities ORDER BY id');
$data = array();
while ($row = mysql_fetch_assoc($result)) {
$data[(int) $row['id']] = array(
'id' => $row['id'],
'name' => $row['name'],
);
}
// This saves a query to the database and a second for loop.
end($data); // move the internal pointer to the end of the array
$max = key($data); // fetch the key of the item the internal pointer is set to
for ($i = 1; $i < $max + 1; $i++) {
if (!isset($data[$i])) {
$data[$i] = array(
'id' => NULL,
'name' => 'Erorr: Missing',
);
}
echo "$i. {$data[$id]['id']} - {$data[$id]['name']}<br />\n";
}
After you've gotten your $localityResult, you could put all of the id's in an array, then before you echo $localityDataStuff, check to see
if(in_array($i, $your_locality_id_array)) {
// do your echoing
} else {
// echo your not found message
}
To make $your_locality_id_array:
$locality_id_array = array();
foreach($localityResult as $locality) {
$locality_id_array[] = $locality['id'];
}
well, i wanna pull out some data from a mysql view, but the wuery dos not seem to retrieve anything ( even though the view has data in it).
here is the code i've been "playing" with ( i'm using adodb for php)
$get_teachers=$db->Execute("select * from lecturer ");
//$array=array();
//fill array with teacher for each lesson
for($j=0;$j<$get_teachers->fetchrow();++$j){
/*$row2 = $get_lessons->fetchrow();
$row3=$row2[0];
$teach=array(array());
//array_push($teach, $row3);
$teach[$j]=mysql_fetch_array( $get_teachers, TYPE );
//echo $row3;*/
$row = $get_teachers->fetchrow();
//$name=$row[0]+" "+$row[0]+"/n";
//array_push($teach, $row1);
echo $row[0]; echo " ";echo $row[1]." ";
//$db->debug = true;
}
if i try something like "select name,surname from users", the query partially works . By partially i mean , while there are 2 users in the database, the loop only prints the last user.
the original query i wanted to execute was this
$get_teachers=$db->Execute("select surname,name from users,assigned_to,lessons
where users.UID=assigned_to.UID and lessons.LID=assigned_to.LID and
lessons.term='".$_GET['term']."'");
but because it didnt seem to do anything i tried with a view ( when you execute this in the phpmyadmin it works fine(by replacing the GET part with a number from 1 to 7 )
the tables in case you wonder are: users,assigned_to and lessons. ( assigned_to is a table connecting each user to a lesson he teaches by containing UID=userid and LID=lessonid ). What i wanted to do here is get the name+surname of the users who teach a lesson. Imagine a list tha displays each lesson+who teaches it based on the term that lesson is available.
Looking at http://adodb.sourceforge.net/ I can see an example on the first page on how to use the library:
$rs = $DB->Execute("select * from table where key=123");
while ($array = $rs->FetchRow()) {
print_r($array);
}
So, you should use:
while ($row = $get_teachers->fetchrow()) {
instead of:
for ($j = 0; $j < $get_teachers->fetchrow(); ++$j) {
The idea with FetchRow() is that it returns the next row in the sequence. It does not return the number of the last row, so you shouldn't use it as a condition in a for loop. You should call it every time you need the next row in the sequence, and, when there are no more rows, it will return false.
Also, take a look at the documentation for FetchRow().
for($j=0;$j<$get_teachers->fetchrow();++$j){
... a few lines later ...
$row = $get_teachers->fetchrow();
See how you call fetchrow() twice before actually printing anything? You remove two rows from the result set for every 1 you actually use.
while ($row = $get_teachers->fetchrow()) {
instead and don't call fetchrow() again within the loop.
Because you're fetching twice first in the loop
for($j=0;$j<$get_teachers->fetchrow();++$j){
... some code ...
// And here you fetch again
$row = $get_teachers->fetchrow();
You should use it like this
while ($row = $get_teachers->fetchrow()) {
I have a SQL database that contains a field. I can get all of the elements in that field by:
$result=mysql_query($sql);
while($row=mysql_fetch_array($result)){
$ftype =$row['ftype']; //name of field is 'ftype'
print $ftype} //do something
I want a random element to be printed out each time the page is opened/refreshed.
Knowing that the result is an array containing the information i want, I want to randomly choose an element of the array. Also, if there are N elements in the array, I want to choose all N elements exactly once before I show any element again for second time. The process repeats itself. I know how to code something like this in java or python, but I don't think that's the way I should go.
I think I need to use javascript, but I'm just not sure what technology to use.
UPDATE:
Patrick's idea seems to be exactly what i was looking for. I thought I would share what I have now and maybe you can suggest optimization. I hope the intent in the code is obvious.
<?
session_start();
if (!isset($_SESSION['count']) || !isset($_SESSION['randomArray'])) {
$count = 0;
$randomArray = array();
$sql="SELECT youtubeurl FROM Foodlist";
$result=mysql_query($sql);
while($row=mysql_fetch_array($result)){
array_push($randomArray,$row['youtubeurl']);
}
shuffle($randomArray);
$_SESSION['randomArray'] = $randomArray;
$_SESSION['count'] = $count;
} elseif ($_SESSION['count'] >= sizeof($_SESSION['randomArray'])){
$_SESSION['count'] = 0;
$randomArray = $_SESSION['randomArray'];
shuffle($randomArray);
$_SESSION['randomArray'] = $randomArray;
} else{
$randomArray = $_SESSION['randomArray'];
$count = $_SESSION['count'];
echo $randomArray[$count];
$_SESSION['count']++;
}
?>
You can do this without Javascript, however you'll need to open/maintain a session.
Pseudocode:
data = data_from_mysql()
choice = random.choice(data, exclude = SESSION['choices'])
SESSION['choices'].append(choice)
print choice
if len(SESSION['choices']) == len(data):
SESSION['choices'] = []
If you want a random result let the dbms take care of it. Add this to the bottom of your sql query.
ORDER BY RAND()
LIMIT 1