I believe I am using the PDO fetch functions completely wrong. Here is what I am trying to do:
Query a row, get the results, use a helper function to process the results into an array.
Query
function userName($db){
$q = $db->prepare("SELECT id, name FROM users WHERE id = :user");
$q->bindParam(":user", $user);
$q->execute();
$qr = $q->fetchAll(PDO::FETCH_ASSOC);
if ($qr->rowCount() > 0){
foreach($qr as $row){
$names[$row['id']] = buildArray($row);
}
return $names;
}
}
My custom array building function
function buildArray($row){
$usernames = array();
if(isset($row['id'])) $usernames['id'] = $row['id'];
if(isset($row['name'])) $usernames['name'] = $row['name'];
}
I'm actually getting exactly what I want from this, but when I echo inbetween I see that things are looping 3 times instead of once. I think I am misusing fetchAll.
Any help appreciated
If you're going to build a new array, there's not much point in having fetchAll() build an array. Write your own fetch() loop:
function userName($db){
$q = $db->prepare("SELECT id, name FROM users WHERE id = :user");
$q->bindParam(":user", $user);
$q->execute();
$names = array();
while ($row = $q->fetch(PDO::FETCH_ASSOC)) {
$names[$row['id']] = $row;
}
return $names;
}
There's also no need for buildArray(), since $row is already the associative array you want.
Related
I create as the following function. how to get all data using this array. when run this function will appear only the first record. but, i want it to appear all the records. what is the error in this code.
public function get_All_Se($stId){
$query = "SELECT * FROM session WHERE stId = '$stId'";
$result = $this->db->query($query) or die($this->db->error);
$data = $result->fetch_array(MYSQLI_ASSOC);
return $data;
}
public function get_All_Se($stId){
$rows=array();
$query = "SELECT * FROM session WHERE stId = '$stId'";
$result = $this->db->query($query) or die($this->db->error);
while($data= $result->fetch_assoc()){
$rows[]=$data;
}
return $rows;
}
Run loop over all results and add to some return array.
$rows = array();
while(($row = $result->fetch_array($result))) {
$rows[] = $row;
}
As the documentation of mysqli::fetch_array() explains, it returns only one row (and not an array containing all the rows as you might think).
The function you are looking for is mysqli::fetch_all(). It returns all the rows in an array.
public function get_All_Se($stId)
{
$query = "SELECT * FROM session WHERE stId = '$stId'";
$result = $this->db->query($query) or die($this->db->error);
return $result->fetch_all(MYSQLI_ASSOC);
}
The code above still has two big issues:
It is open to SQL injection. Use prepared statements to avoid it.
or die() is not the proper way to handle the errors. It looks nice in a tutorial but in production code it is a sign you don't care about how your code works and, by extension, what value it provides to their users. Throw an exception, catch it and handle it (log the error, put some message on screen etc) in the main program.
Try this way...
<?php
// run query
$query = mysql_query("SELECT * FROM <tableName>");
// set array
$array = array();
// look through query
while($row = mysql_fetch_assoc($query)){
// add each row returned into an array
$array[] = $row;
// OR just echo the data:
echo $row['<fieldName>']; // etc
}
// debug:
print_r($array); // show all array data
echo $array[0]['<fieldName>'];
?>
I often need to retrieve results and access them by a given column.
Is there a way to write this without walking through the whole dataset each time?
I looked into various PDO fetch modes, but nothing jumped out as being simpler than that. Thanks.
function get_groups() {
$stmt = $dbc->prepare("SELECT * FROM groups ORDER BY group_name");
$stmt->execute();
$groups = $stmt->fetchAll();
$return = [];
foreach($groups as $group) {
$return[$group['id']] = $group;
}
return $return;
}
My proposed solution was pretty obsolete. The right solution comes from this answer
$stmt = $pdo->query("SELECT foo,baz FROM bar")
$groupedByFooValuesArray = $stmt->fetchAll(\PDO::FETCH_GROUP|\PDO::FETCH_UNIQUE)
to group it by another column, change the first column you select
if your goal is to have your same array indexed by different column values, I think the only option is to actually index them by different column values.
you can do that by controlling by which field the array is returned
function get_groups($sql,$key,$values='') {
if ($values != '') {
$stmt = $dbc->prepare($sql);
$stmt->execute($values);
$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
}
else {
$rows = $dbc->query($sql)->fetchAll(PDO::FETCH_ASSOC);
}
foreach ($rows as $row) {
$indexed[$row[$key]] = $row;
}
return $indexed;
}
then, use get_groups to build an indexed array:
$sql = 'SELECT * FROM groups ORDER BY group_name'
var_dump(get_groups($sql,'id'));
There might be a way to store a resultset in some way that you can fetchAll() it multiple times, that would be awesome. but I don't know it.
I have a PHP function that extract dat of an invoice from DB.
The invoice may have more then one line (one product).
function getInvoiceLines($id)
{
$res = mysql_query("select * from invoice_lines where id = $id ");
while ($row = mysql_fetch_array($res))
{
$res_retun['ref']=$row['ref'];
$res_retun['label']=$row['label'];
$res_retun['price']=$row['label'];
$res_retun['qty']=$row['qty'];
}
return $res_retun ;
}
I found this link Create a Multidimensional Array with PHP and MySQL and I made this code using that concept.
Now, how can I move something like a cursor to the next line and add more lines if there's more in MySQL result??
If it's possible, how can I do to show data in HTML with for ??
A little modification should get what you want, below the [] operator is a shorthand notation to add elements to an array, the problem with your code is that you are overwriting the same keys on each iteration
// fetch only what you need;
$res = mysql_query("select ref, label, price, qty from invoice_lines where id = $id ");
while ($row = mysql_fetch_array($res))
{
$res_return[] = $row;
}
return $res_return;
Note, I fixed some of your typos (you were using $rw instead of $row in the loop of your original code)
If you used PDO with fetchAll() you would be returned with the array your expecting, also be safe from nastys:
<?php //Cut down
$db = new PDO("mysql:host=localhost;dbname=dbName", 'root', 'pass');
$sql = "SELECT * FROM invoice_lines WHERE id = :id ";
$stmt = $db->prepare($sql);
$stmt->bindParam(':id', $id);
$stmt->execute();
$res_return = $stmt->fetchAll(PDO::FETCH_ASSOC);
?>
Then you just loop through the array like with any other array:
<?php
foreach($res_return as $row){
echo $row['ref'];
...
...
}
?>
Also id should not have more then 1 row it should be unique IF its your primary key.
If you were using PDO like you should be it would be super easy and you would solve your sql injection issues
$db = new PDO(...);
function getInvoiceLines( $db, $id )
{
$stmnt = $db->prepare("select ref, label, price, qty from invoice_lines where id=?");
$stmnt->execute( array( $id ) );
return $stmnt->fetchAll( PDO::FETCH_ASSOC );
}
Make variable global first Then access it in function. For exp.
$return_arr = array(); // outside function
$i = 0;
cal_recursive(); // call function first time
function cal_recursive(){
global $return_arr;
global $i;
$return_arr[$i] = // here push value to array variable
$i++;
// do code for recursive function
return $return_arr // after end
}
I am building a function that acts like Drupal's variable_initialize() function that pulls all key/value pairs into a global variable. I am trying to find the proper parameters I need to put into fetchAll() to remove the row number and get basically what fetch(PDO::FETCH_ASSOC) does but for all returned rows.
I basically want fetchAll to return:
Array {
[name] = value,
[name2] = value2,
[name3] = value3,
}
The variable table is a simple 2 column table (name)|(value)
function variable_init() {
global $db, $variable;
$query = "SELECT * FROM variable";
$stmt = $db->prepare($query);
$stmt->execute();
$result = $stmt->fetchAll(); //need help here
foreach($result as $name => $value) {
$variable[$name] = $value;
}
}
I have tried PDO_COLUMN/PDO_GROUP/etc... but I can't seem to offset the array to remove the row numbers. Thanks.
I think you may be getting confused about what PDOStatement::fetchAll() returns.
The method returns all rows (arrays or objects, depending on fetch style) in an array.
Try this
$result = $stmt->fetchAll(PDO::FETCH_ASSOC);
foreach ($result as $row) {
$variable[$row['name']] = $row['value'];
}
I want to make a simple function that I can call on to query my database. I pass the "where" part of the query to it and in the code below, my $q variable is correct. However, what should I then do to be able to use the data? I'm so confused at how to do something I'm sure is extremely easy. Any help is greatly appreciated!
function getListings($where_clause)
{
$q = "SELECT * FROM `listings` $where_clause";
$result = mysql_query($q,$dbh);
foreach (mysql_fetch_array($result) as $row) {
$listingdata[] = $row;
}
return $listingdata;
}
Your function should be like this:
function getListings($where_clause, $dbh)
{
$q = "SELECT * FROM `listings` $where_clause";
$result = mysql_query($q, $dbh);
$listingdata = array();
while($row = mysql_fetch_array($result))
$listingdata[] = $row;
return $listingdata;
}
Improvements over your function:
Adds MySQL link $dbh in function arguments. Passit, otherwise query will not work.
Use while loop instead of foreach. Read more here.
Initialize listingdata array so that when there is no rows returned, you still get an empty array instead of nothing.
Do you have a valid db connection? You'll need to create the connection (apparently named $dbh) within the function, pass it in as an argument, or load it into the function's scope as a global in order for $result = mysql_query($q,$dbh); to work.
You need to use while, not foreach, with mysql_fetch_array, or else only the first row will be fetched and you'll be iterating over the columns in that row.
$q = "SELECT * FROM `listings` $where_clause";
$result = mysql_query($q,$dbh);
while (($row = mysql_fetch_array($result)) != false)
{
$listingdata[] = $row;
}
Always add error handling in your code. That way you'll see what is going wrong.
$result = mysql_query($q,$dbh);
if (!$result) {
trigger_error('Invalid query: ' . mysql_error()." in ".$q);
}
Here is a function which will save you some time. First Argument tablename, then condition(where), fields and the order. A simple query will look like this : query_db('tablename');
function query_db($tbl_name,$condition = "`ID` > 0",$fields = "*",$order="`ID` DESC"){
$query="SELECT ".$fields." FROM `".$tbl_name."` WHERE ".$condition." ORDER BY".$order;
$query=$con->query($query);
$row_data=array();
while($rows = $query->fetch_array()){
$row_data[] = $rows;
}
return $row_data;
}