I have a table that contains
column 1 = state column 2 = link
Alabama auburn.alabama.com
Alabama bham.alabama.com
Alabama dothan.alabama.com
I need to grab from my database table and put into an array that i can array_walk() through. they need to be accessed like this array.
$arraytable = array(
"auburn.alabama.com"=>"Alabama",
"bham.alabama.com"=>"Alabama",
"dothan.alabama.com"=>"Alabama",
);
I have tried everything but not sure how make this work using php to print the array like such. Any help is greatly appreciated.
Note Your question title is inconsistent with your example. In the title you ask for column 1 as the key, but your example uses column 2 as the key. I've used column 2 here...
It isn't clear what MySQL API you are using to fetch, but whichever it is, use the associative fetch method and create new array keys using the pattern $arraytable[$newkey] = $newvalue. This example would be in object-oriented MySQLi:
$arraytable = array();
while($row = $result->fetch_assoc()) {
// Create a new array key with the 'link' and assign the 'state'
$arraytable[$row['link']] = $row['state'];
}
You can use array_column for this, since PHP5.5 (http://php.net/array_column)
Description
array array_column ( array $array , mixed $column_key [, mixed $index_key = null ] )
array_column() returns the values from a single column of the array, identified by the column_key. Optionally, you may provide an index_key to index the values in the returned array by the values from the index_key column in the input array.
For PHP < 5.5:
https://github.com/ramsey/array_column/blob/master/src/array_column.php
To implement AcidReign's suggestion, here is the snippet:
Code: (Demo)
$resultset = [
['state' => 'Alabama', 'link' => 'auburn.alabama.com'],
['state' => 'Alabama', 'link' => 'bham.alabama.com'],
['state' => 'Alabama', 'link' => 'dothan.alabama.com']
];
var_export(array_column($resultset, 'state', 'link'));
// ^^^^-- use this column's data for keys
// ^^^^^-- use this column's data for values
Output:
array (
'auburn.alabama.com' => 'Alabama',
'bham.alabama.com' => 'Alabama',
'dothan.alabama.com' => 'Alabama',
)
However, array_column() won't directly work on a result set object, but a foreach() can immediately access the data set using array syntax without any fetching function calls.
Body-less foreach: (Demo)
$result = [];
foreach ($mysqli->query('SELECT * FROM my_table') as ['link' => $link, 'state' => $result[$link]]);
var_export($result);
Or a foreach with a body: (Demo)
$result = [];
foreach ($mysqli->query('SELECT * FROM my_table') as $row) {
$result[$row['link']] = $row['state'];
}
var_export($result);
All of the above snippets return:
array (
'auburn.alabama.com' => 'Alabama',
'bham.alabama.com' => 'Alabama',
'dothan.alabama.com' => 'Alabama',
)
Related
I wrote this function to get a subset of an array. Does php have a built in function for this. I can't find one in the docs. Seems like a waste if I'm reinventing the wheel.
function array_subset($array, $keys) {
$result = array();
foreach($keys as $key){
$result[$key] = $array[$key];
}
return $result;
}
I always want this too. Like a PHP version of Underscore's pick.
It's ugly and counter-intuitive, but what I sometimes do is this (I think this may be what prodigitalson was getting at):
$a = ['foo'=>'bar', 'zam'=>'baz', 'zoo'=>'doo'];
// Extract foo and zoo but not zam
print_r(array_intersect_key($a, array_flip(['foo', 'zoo'])));
/*
Array
(
[foo] => bar
[zoo] => doo
)
*/
array_intersect_key returns all the elements of the first argument whose keys are present in the 2nd argument (and all subsequent arguments, if any). But, since it compares keys to keys, I use array_flip for convenience. I could also have just used ['foo' => null, 'zoo' => null] but that's even uglier.
array_diff_key and array_intersect_key are probably what you want.
There is no direct function I think in PHP to get a subset from an array1 with compare to another array2 where the values are the list of key name which we fetch.
Like: array_only($array1, 'field1','field2');
But this way can be achieved the same.
<?php
$associative_array = ['firstname' => 'John', 'lastname' => 'Smith', 'DOB' => '2000-10-10', 'country' => 'Ireland' ];
$subset = array_intersect_key( $associative_array, array_flip( [ 'lastname', 'country' ] ) );
print_r( $subset );
// Outputs...
// Array ( [lastname] => Smith [country] => Ireland );
I have this array:
$datas = array(
array(
'id' => '1',
'country' => 'Canada',
'cities' => array(
array(
'city' => 'Montreal',
'lang' => 'french'
),
array(
'city' => 'Ottawa',
'lang' => 'english'
)
)
)
);
Question 1:
How can I get the the country name when I have the id ?
I tried: $datas['id'][1] => 'country'
Question 2:
How can I loop in the cities when I have the id ?
I tried:
foreach ($datas as $data => $info) {
foreach ($info['cities'] as $item) {
echo '<li>'.$item['city'].'</li>';
}
}
Thanks a lot.
You have the ID of the array you want analyse, but your array is structured as a map, meaning that there are no keys in the outer array. You will therefore have to iterate the array first to find the object you are looking for.
While the first approach would be to search for the object that has the ID you are looking for, i suggest you map your arrays with their IDs. To do that, you can use two PHP array functions: array_column and array_combine.
array_column can extract a specific field of each element in an array. Since you have multiple country objects, we want to extract the ID from it to later use it as a key.
array_combine takes two arrays with the same size to create a new associative array. The values of the first array will then be used as keys, while the ones of the second array will be used as values.
$mappedCountries = array_combine(array_column($datas, 'id'), $datas);
Assuming that the key 1 is stored in the variable $key = 1;, you can afterwards use $mappedCountries[$key]['country'] to get the name of the country and $mappedCountries[$key]['cities'] to get the cities, over which you can then iterate.
if there might be many arrays in $datas and you want to find one by id (or some other key) you can do something like this:
function search($datas, $key, $value) {
foreach($datas as $data) {
if ($data[$key] === $value) {
return $data;
}
}
So if you want to find where id = 1
$result = search($datas, 'id', '1');
and then you can get country echo $result['country'] or whatever you need.
i'm having an array which contains record ids as follows:
Array
(
[0] => 113
[1] => 43
[2] => 64
)
so for achieving the corresponding records, i'd have to run 3 queries:
select * from mytable where id=113
select * from mytable where id=43
select * from mytable where id=64
my question: wouldn't it be possible executing just ONE query on the whole table then directly access the mysqli result like an associative array by passing the ID?
something like $record = $res['id'][113];?
thanks in advance
You need the IN clause
SELECT * FROM mytable WHERE id IN ( 113,43,64 );
Custom function indexme takes an array of arrays (numeric or associative) and by default gets the first element value of each sub-array and makes it the associative index in a return array. Optionally, a column name can be passed as the second parameter to designate which column value to use for the index.
$array = array(array('id' => 12, 'name' => 'Joe'), array('id' => 9, 'name' => 'Jane'));
$array_keyed = indexme($array);
// > array(12 => array('id' => 12, 'name' => 'Joe'), 9 => array('id' => 9, 'name' => 'Jane'));
print $array_keyed[12]['name'];
// > Joe
function indexme($arr, $key = '') { // <- custom function indexme
$return_arr = array();
if ( '' == $key ) {
$keys = array_keys($arr[0]);
$key = $keys[0];
}
foreach ( $arr as $value ) {
$return_arr[$value[$key]] = $value;
}
return $return_arr;
}
Pass the mysqli response to this function to make an ID indexed array:
$results_keyed = indexme($result->fetch_assoc(), 'id');
Check out the accepted answer on this page MySQL Prepared statements with a variable size variable list for a nice solution to the WHERE IN technique.
I have an array that looks like this:
Array([0]=>Array([id]=>7 [name]=foo) [1]=>Array([id]=>10 [name]=bar) [2]=>Array([id]=>15 [name]=baz))
Each index contains an another array with various elements including an 'id'. I would like to "go up" a level, such that my top-level array is indexed by the ID element of the corresponding nested arrays, but that index still contains an array with all of the elements that were in the sub arrays?
In other words, how can I use PHP to turn the above array into this:
Array([7]=>Array([id]=>7 [name]=foo) [10]=>Array([id]=>10 [name]=bar) [15]=>Array([id]=>15 [name]=baz))
What you need to do here is extract the ids from each sub-array in your input. If you have these as an array of ids, you are just an array_combine call away from re-indexing your original array to use these ids as the keys.
You can produce such an array of ids using array_map, which leads to:
// input data
$array = array(array('id' => '7', 'name' => 'foo'),array('id' => 10, 'name' => 'bar'));
// extract ids from the input array
$ids = array_map(function($arr) { return $arr['id']; }, $array);
// "reindex" original array using ids as array keys, keep original values
$result = array_combine($ids, $array);
print_r($result);
The syntax I 've used for the anonymous function (first argument to array_map) requires PHP >= 5.3, but you can achieve the same (although a bit less conveniently) with create_function in any PHP version you 'd not be ashamed of using.
See it in action.
In modern, supported versions of PHP, this whole task can be achieved with array_column() alone.
Using null as the second parameter will leave the rows unchanged.
Using id as the 3rd parameter will assign those columnar values as the new first level keys. Be aware that if these columnar values are not unique, subsequently encountered duplicates will overwrite previously encountered rows with the same id value -- this is because keys cannot be duplicates on a given level in an array.
DO NOT bother calling array_combine(), it is simply unnecessary/indirect.
Code: (Demo)
$array = [
['id' => 7, 'name' => 'foo'],
['id' => 10, 'name' => 'bar'],
['id' => 15, 'name' => 'baz'],
];
var_export(
array_column($array, null, 'id')
);
Output:
array (
7 =>
array (
'id' => 7,
'name' => 'foo',
),
10 =>
array (
'id' => 10,
'name' => 'bar',
),
15 =>
array (
'id' => 15,
'name' => 'baz',
),
)
Try this:
$newArray = array();
foreach($oldArray as $key => $value) {
$newArray[$value['id']] = $value;
}
Since PHP 5.5.0, you can shorten the code by using array_column() instead of array_map().
$result = array_combine(array_column($array, 'id'), $array);
Given this multidimensional array, I'm trying to retrieve the value of one of the child keys:
$movieCast = Array(
'1280741692' => Array(
...
, 'userid' => 62
, 'country_id' => '00002'
...
)
, '1280744592' => Array(
...
, 'userid' => 62
, 'country_id' => '00002'
...
)
)
How can I retrieve the value of country_id?
The top-level array key could be anything and the value of country_id will always be the same for a specific user. In this example, user #62's country_id will always be 00002.
You have to iterate through the outer array:
foreach ($outer as $inner) {
//do something with $inner["country_id"]
}
Another option is to build an array with the contry_ids (example uses PHP >=5.3 functionality, but that can be worked around easily in earlier versions):
array_map(function ($inner) { return $inner["country_id"]; }, $outer);
EDIT If the ids are all the same, even easier. Do:
$inner = reset($outer); //gives first element (and resets array pointer)
$id = $inner["country_id"];
a more general-purpose solution using php 5.3:
function pick($array,$column) {
return array_map(
function($record) use($column) {
return $record[$column];
},
$array
);
}
You need to use this:
array_column($movieCast, 'country_id')
The result will be:
array (
0 => '00002',
1 => '00002',
)