php variable scope inside a loop in a function - php

I am wondering is there any way to get the value of a variable, that was defined in a loop inside a function?
Do variables declared in a loop / if-then-else, etc have a limited scope (only inside these blocks)?
here is an example of a function:
<?php
function getComments($tabName) {
$sql = "select
a.owner,
a.table_name,
a.column_name,
a.data_type,
a.data_length,
a.data_precision,
b.comments
from
all_tab_columns a,
user_col_comments b
where
a.TABLE_NAME = b.table_name
and a.COLUMN_NAME = b.column_name
and a.owner = 'CORE'
and a.table_name ='" . $tabName . "'
order by
a.column_id";
$stid = oci_parse(getConnect(), $sql);
// runs the query above
oci_execute($stid);
while ($row = oci_fetch_array($stid, OCI_ASSOC + OCI_RETURN_NULLS)) {
foreach ($row as $column => $entry) {
// Column name
if ($column == 'COLUMN_NAME') {
$output = "this is a column";
}
}
}
return $output;
}
And here I get the "Undefined variable: output" error.
if I put echo instead the $output variable, I get the result.
Is it because the $output scope? How can I get the $output value in my return?

try to satisfy this condition
if ($column == 'COLUMN_NAME') {
$output = "this is a column";
}
and also u can try to return immediately after ur condition
if ($column == 'COLUMN_NAME') {
return "this is a column";
}

Related

Call MySql Select Query in 2 different php function

Please help me with my problem.. can i call once Mysql Select Query from different function from two different function too... Sorry i don't know how to explain.. but below my sample what i want to archive..
I want use single query for 2 function.. so maybe i have to write code like below?
function sqlSelect ($db, $id, $id2) {
$sql = mysqli_query($db, "SELECT * FROM xxx WHERE id='$id' AND id2='$id2'");
$row = mysqli_num_rows($sql);
$field = mysqli_fetch_object($sql);
return $row;
}
but how to use $field inside 2 diff function?
function aaa ($a,$b,$c) {
if($row >= 1){
//Do something with $a $b and $c
//$reget field with $field['column'];
$field['column']; //???
}
return $result;
}
function bbb ($a,$b,$c) {
if($row >= 1){
//Do something with $a $b and $c
//get field with $field['column'];
$field['column']; //???
}
}
what i do right now is
function aaa ($db,$id,$id2,$a,$b,$c) {
$sql = mysqli_query($db, "SELECT * FROM xxx WHERE id='$id' AND id2='$id2'");
$row = mysqli_num_rows($sql);
$field = mysqli_fetch_object($sql);
if($row >= 1){
//Do something with $a $b and $c
//get field with $field['column'];
}
}
function bbb ($db,$id,$id2,$a,$b,$c) {
$sql = mysqli_query($db, "SELECT * FROM xxx WHERE id='$id' AND id2='$id2'");
$row = mysqli_num_rows($sql);
$field = mysqli_fetch_object($sql);
if($row >= 1){
//Do something with $a $b and $c
//get field with $field['column'];
}
}
But if i use what i write and code right now i think it's have to call same query twice. I cannot use query outside function so i have to write query on each function but i want to just write query once and can use in two different function..
Sorry for stupid explanation..
Thank you for help
One implementation can be as follow by passing an array as argument,
<?php
$arg['db']="database";
$arg['tabe']="table";
$arg['search']['id1']="id1";
$arg['search']['id2']="id2";
$arg['do_something']['a']="a";
$arg['do_something']['b']="b";
$arg['do_something']['c']="c";
function searchAndDoSomethingAndReturnResult($arg)
{
$return = NULL;
$query="SELECT * FROM ".$arg['table'];
$flag=false;
foreach($arg['search'] as $key=>$value)
{
if($flag)
$query.=" AND ";
else
$flag=true;
$query.= $key." = '".$value."' ";
}
$row = mysqli_num_rows($query);
$field = mysqli_fetch_object($query);
if($row >= 1)
{
foreach($arg['do_something'] as $job=>$value)
{
// $return[] = "some result"
// do something
}
}
return $return;
}
?>
let me know if this solve your problem
You can either pass in the $field variable as a function argument
<?
$field = ...;
function sql1($field,...,...){
// Use $field here
}
function sql2($field,...,...){
// Use $field here
}
?>
Alternatively, you can use the global keyword to access variables from outside of the function
<?
$field = ...;
function sql1(){
global $field;
// Use $field here
}
function sql2(){
global $field;
// Use $field here
}
?>

Check for empty rowset in oci_fetch_array

I am doing the following...
$approved = oci_parse($conn_prs, "select * from patch_files where patch_reviewer = '". $_SESSION['id'] ."' and patch_status = 'Approved'"); // now rows available for current id
oci_execute($approved);
while ($row = oci_fetch_array($approved, OCI_BOTH + OCI_RETURN_NULLS )) {
var_dump($row); // shows nothing
if ($row == null) { echo "<p>None Found...</p>"; }
else { ....
Not sure why the null condition is not working...
Your null condition is not working because $row is never null. oci_fetch_array() returns an array of the row fields, or false. If there are no rows your while loop is not executed.
You seem to have misunderstood the purpose of OCI_RETURN_NULLS. When used, it creates array elements for empty fields in $row, not an empty array if there are no rows.
A quick and dirty way to do what you want is:
$i = 0;
while ($row = oci_fetch_array($approved, OCI_BOTH + OCI_RETURN_NULLS)) {
$i++;
...
}
if ($i == 0) {
echo "<p>None Found...</p>";
}
try with -
while ($row = oci_fetch_array($approved, OCI_BOTH + OCI_RETURN_NULLS )) {
var_dump($row); // shows nothing
if (empty($row)) { echo "<p>None Found...</p>"; }
else { ....
oci_fetch_array() - returns the next row from a query as an array.

php while loop running only once

I have a php script for check the availability of some data. I call this script from external jquery. the jquery is running fine. here is my php:
<?php
$avares = checkAva($fi_nm, $tbl_nm, $txtval);
echo $avares;
function checkAva($field, $table, $curval) {
$avres = mysql_query("SELECT " . $field . " FROM " . $table . "") or die("query failed");
while ($a_row = mysql_fetch_array($avres)) {
$dbval = $a_row[$field];
if ($curval == $dbval) {
return "no";
} else {
return "yes";
}
}
}
?>
$curval is the variable coming from external jquery. my problem is that the while loop seems to run only once though there are lot of entries in the DB. I checked it with an integer variable and the while loop seems to run only once. can you help me to solve that?
Look at your code.
while ($a_row = mysql_fetch_array($avres)) {
$dbval = $a_row[$field];
if ($curval == $dbval) {
return "no";
} else {
return "yes";
}
}
you have used return, if its true it returns and false then also returns change those according to your needs. The return statement immediately ends execution of the current function
It will by design as you have a return statement. From what you have said your not actually wanting it to return but to set a variable that at end of execution will return no or yes. I could be wrong on this but hey ho.
<?php
echo checkAva($fi_nm, $tbl_nm, $txtval);
function checkAva($field, $table, $curval) {
$avres = mysql_query("SELECT " . $field . " FROM " . $table) or die("query failed");
$noOrYes = "yes";
while ($a_row = mysql_fetch_array($avres)) {
if($curval == $a_row[$field]) {
$noOrYes = "no";
}
}
return $noOrYes;
}
?>
The possible issue that can cause Loop to iterate once are:
Error in the Variable used for the $query and $result
Same name Variable inside and outside of the Loop
Incorrect placement of Return statement
Invalid Mysql Statement
Directly put the condition in your Query like
function checkAva($field, $table, $curval) {
$avres = mysql_query("SELECT " . $field . " FROM " . $table . "
WHERE `".$field."` = '".$curVal."'");
$res = mysql_fetch_array($avres);
if(is_array($res) && count($res) > 0)
return "Yes";
else
return "No";
}
Instead of getting all the results and checking with each one of the result you directly put a condition to extract the results which satisfies your condition.This will be suggestable if you have many records.
You need to put one of the return outside of the while loop.
For example if you just wanted to check if $curval == $dbval
while ($a_row = mysql_fetch_array($avres)) {
$dbval = $a_row[$field];
//If the condition was met return with a no
if ($curval == $dbval) {
return "no";
}
}
//If the condition was not met return yes
return yes;
That's basically what you need to do so the loop will run until your condition was met or not at all.

Merging PHP IF statements to a single statement or function

So I have some code that it seems that I have to repeat over and over again for $round == P,1,2 and A. Is there any I can achieve this without producing redundant code?
I'm thinking of writing a function that simply swaps through through all 3 possible $round variables that can be available and echoing the relevant information. Any idea on how to achieve this?
The other information will remain the same - its only $round that will change,
// determine previous round
if($round == "P") echo "";
// if we are in round 1, look up round P bookings
if($round == "1")
{
$sql = "SELECT
*
FROM ts_request
INNER JOIN ts_day
ON ts_request.day_id = ts_day.id
INNER JOIN ts_period
ON ts_request.period_id = ts_period.id
INNER JOIN ts_allocation
ON ts_request.id = ts_allocation.request_id
WHERE ts_request.round=:round
AND ts_request.dept_id=:dept
ORDER BY ts_request.module_id ASC";
$stm = $pdo->prepare( $sql );
$stm->execute( array( ':round' => 'P', ':dept' => $loggedin_id ) );
$rows = $stm->fetchAll();
foreach ($rows as $row)
{
echo '<tr align="center">';
echo '<td>'.$row['module_id'].'</td>';
echo '<td>'.$row['day'].'</td>';
echo '<td>'.$row['period'].'</td>';
echo '<td>';
$sql = "SELECT * FROM ts_roompref
WHERE request_id=:id";
$stm = $pdo->prepare( $sql );
$stm->execute( array( ':id' => $row['request_id']) );
$rows2 = $stm->fetchAll();
foreach ($rows2 as $row2)
{
if ($row2['room_id']=="0")
{
echo "Any<br>";
}
else
{
echo $row2['room_id'].'<br>';
}
}
echo '</td>';
echo '<td>'.$row['status'].'</td>';
echo '</tr>';
}
}
// if we are in round 2, look up round 1 bookings
if($round == "2")
{
$sql .= "";
}
foreach ($rows as $row)
{
// echo results here
};
// if we are in round A, look up round 2 bookings
if($round == "A")
{
$sql .= "";
}
foreach ($rows as $row)
{
// echo results here
};
This may help.
$roundsInOrder = array('P', '1', '2', 'A');
$roundKey = array_search($incomingRoundLetter, $roundsInOrder);
if ($roundKey !== false || $roundKey != 0) {
$roundToQuery = $roundsInOrder[$roundKey - 1];
// your other code snipped
$stm->execute( array( ':round' => $roundToQuery, ':dept' => $loggedin_id ) );
//more code here
}
What this code does:
It sets up the rounds in order. Then, it searches the rounds for the incoming round. We really want the key. Then, the if statement checks to a) make sure we have actually found the round and b) the round is not the first one (0 = P) because we don't want to do any query then. Finally, the $roundToQuery gets the value out of the rounds that is directly before the current key.
I think what you are searching for is the switch() function in php.
Here is a nice and simple tutorial on how to use it:
http://www.tizag.com/phpT/switch.php
Hope this helps.
"Swapping" already exists, it's called "switch statement". In your case it should look like this:
switch($round) {
case "P":
//code
break;
case "1":
//code
break;
case "2":
//code
break;
case "A":
//code
break;
default:
//code, when value of $round doesn't match any case
break;
}

using a $_GET id to filter a mysql_fetch_array in PHP

So I have a query that I am returning all of the items into a mysql_fetch_array. Now, I know I could write another query and just select the items I need into a seperate query but, is there a way to just filter from the larger query what I want dependent on $_GET?
So, in english the user comes from a hyperlink that has ?id=1 and I peform a while that gets the all the values but, only display the $_GET['id'] items in a list
<?php //give ma all values but only echo out list of the $_GET['id'] in the url
while ($row = mysql_fetch_array($result) {
$id = $rowvideo["id"];
$title = $rowvideo["title"];
$length = $rowvideo["length"];
}
echo("<li><a href='#'>". $title." " .$length. "</a></li>");
?>
Hope this makes sense. Thank you all.
If you do not want a second query to get just what you need, a simple-if-statement in your loop should work:
<?php
$getId = isset($_GET['id']) ? $_GET['id'] : false;
//give ma all values but only echo out list of the $_GET['id'] in the url
while ($row = mysql_fetch_array($result)) {
$id = $row["id"];
$title = $row["title"];
$length = $row["length"];
if ($id == $getId) {
echo("<li><a href='#'>". $title." " .$length. "</a></li>");
}
}
?>
Note that I declared $getId outside of the loop to prevent having to use isset() during every iteration. If you don't verify if it's set and attempt to use it it will throw an undefined index warning - assuming you have error_reporting turned on (with that level enabled).
Alternatively, you could use PHP's array_filter() on the data after you've parsed it all:
$results = array();
while ($row = mysql_fetch_array($result)) $results[] = $row;
if (isset($_GET['id'])) {
$filtered = array_filter($results, function($element) use ($_GET['id']) { return ($element['id'] == $_GET['id']); });
$results = $filtered;
}
foreach ($results as $result) {
echo("<li><a href='#'>". $result['title']." " .$result['length']. "</a></li>");
}
My personal opinion would be to be more efficient and write the second query though, assuming of course you don't actually need all of the results when an id is specified. It would be as simple as:
if (isset($_GET['id']) && is_numeric($_GET['id'])) {
$query = 'SELECT id, title, length FROM table WHERE id=' . (int)$_GET['id'];
} else {
$query = 'SELECT id, title, length FROM table';
}
// your existing code as-is
A little more clarity here:
This will allow the filter by id in the url by specifying id=xxx, IF xxx is an integer that is positive. So id of 'bob' or -1 will not filter the results still giving all results
$filter=false;
if(isset($_GET['id']))
{
$filter_id=intval($_GET['id']);
if($id>0) $filter=true;
}
while($row = mysql_fetch_array($result))
{
if( (!$filter) || ( ($filter) && ($filter_id==$row['id']) ) )
{
$id = $row["id"];
$title = $row["title"];
$length = $row["length"];
// do other stuff here
}
}
I also changed $rowvideo to $row as this is the array you used to fetch the results.
<?php //give ma all values but only echo out list of the $_GET['id'] in the url
while ($row = mysql_fetch_array($result)) {
$id = $rowvideo["id"];
$title = $rowvideo["title"];
$length = $rowvideo["length"];
if ($id == $_GET['id']) { // or even ===
echo("<li><a href='#'>". $title." " .$length. "</a></li>");
}
}
?>

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