I often like to have my results sent elsewhere in the format of an array (although keep in mind that if you just plan on traversing through the array in another part of the script, this extra step is just a waste of time).
This is my one-liner for transforming a mysqli_result set into an array.
<?php
$sql = new MySQLi($host, $username, $password, $database);
$result = $sql->query("SELECT * FROM `$table`;");
for ($set = array (); $row = $result->fetch_assoc(); $set[] = $row);
print_r($set);
?>
Outputs:
Array
(
[0] => Array
(
[id] => 1
[field2] => a
[field3] => b
),
[1] => Array
(
[id] => 2
[field2] => c
[field3] => d
)
)
I use other variations to adapt to the situation, i.e. if I am selecting only one field:
<?php
$sql = new MySQLi($host, $username, $password, $database);
$result = $sql->query("SELECT `field2` FROM `$table`;");
for ($set = array (); $row = $result->fetch_assoc(); $set[] = $row['field2']);
print_r($set);
?>
Outputs:
Array
(
[0] => a
[1] => c
)
Or, to make the array associative with the primary index (code assumes primary index is the first field in the table):
<?php
$sql = new MySQLi($host, $username, $password, $database);
$result = $sql->query("SELECT * FROM `$table`;");
for ($set = array (); $row = $result->fetch_assoc(); $set[array_shift($row)] = $row);
print_r($set);
?>
Outputs:
Array
(
[1] => Array
(
[field2] => a
[field3] => b
),
[2] => Array
(
[field2] => c
[field3] => d
)
)
mysqli_result::fetch_assoc
mysqli_fetch_assoc
(PHP 5, PHP 7)
mysqli_result::fetch_assoc -- mysqli_fetch_assoc — Fetch a result row as an associative array
Descrierea
Stil obiect-orientat
public mysqli_result::fetch_assoc
(
) : array
Stil procedural
Returns an associative array that corresponds to the fetched row or null
if there are no more rows.
Notă: Numele câmpurilor întoarse de această funcție sunt sensibile la literele majuscule/minuscule.
Notă: Această funcție stabilește câmpurile NULL la valoarea PHP
null.
Parametri
-
result -
Numai stilul procedural: Un identificator al setului de rezultate întors de mysqli_query(), mysqli_store_result() sau mysqli_use_result ().
Valorile întoarse
Returns an associative array of strings representing the fetched row in the result
set, where each key in the array represents the name of one of the result
set's columns or null if there are no more rows in resultset.
If two or more columns of the result have the same field names, the last column will take precedence. To access the other column(s) of the same name, you either need to access the result with numeric indices by using mysqli_fetch_row() or add alias names.
Exemple
Example #1 Stil obiect-orientat
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if ($mysqli->connect_errno) {
printf("Connect failed: %s\n", $mysqli->connect_error);
exit();
}
$query = "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 50,5";
if ($result = $mysqli->query($query)) {
/* fetch associative array */
while ($row = $result->fetch_assoc()) {
printf ("%s (%s)\n", $row["Name"], $row["CountryCode"]);
}
/* free result set */
$result->free();
}
/* close connection */
$mysqli->close();
?>
Example #2 Stil procedural
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$query = "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 50,5";
if ($result = mysqli_query($link, $query)) {
/* fetch associative array */
while ($row = mysqli_fetch_assoc($result)) {
printf ("%s (%s)\n", $row["Name"], $row["CountryCode"]);
}
/* free result set */
mysqli_free_result($result);
}
/* close connection */
mysqli_close($link);
?>
Exemplele de mai sus vor afișa:
Pueblo (USA) Arvada (USA) Cape Coral (USA) Green Bay (USA) Santa Clara (USA)
Example #3 A mysqli_result example comparing iterator usage
<?php
$c = mysqli_connect('127.0.0.1','user', 'pass');
// Using iterators (support was added with PHP 5.4)
foreach ( $c->query('SELECT user,host FROM mysql.user') as $row ) {
printf("'%s'@'%s'\n", $row['user'], $row['host']);
}
echo "\n==================\n";
// Not using iterators
$result = $c->query('SELECT user,host FROM mysql.user');
while ($row = $result->fetch_assoc()) {
printf("'%s'@'%s'\n", $row['user'], $row['host']);
}
?>
Exemplul de mai sus va afișa ceva similar cu:
'root'@'192.168.1.1' 'root'@'127.0.0.1' 'dude'@'localhost' 'lebowski'@'localhost' ================== 'root'@'192.168.1.1' 'root'@'127.0.0.1' 'dude'@'localhost' 'lebowski'@'localhost'
A se vedea și
- mysqli_fetch_array() - Fetch a result row as an associative, a numeric array, or both
- mysqli_fetch_row() - Get a result row as an enumerated array
- mysqli_fetch_object() - Returns the current row of a result set as an object
- mysqli_query() - Performs a query on the database
- mysqli_data_seek() - Adjusts the result pointer to an arbitrary row in the result
add a note
User Contributed Notes 6 notes
Miller ¶
11 years ago
Enrique Garcia ¶
1 year ago
There is a difference between MariaDB and MySQL(>5.4) whether the input parameter (mysqli object) has data or is empty (it comes from a previus query).
-MariaDB: you get an exception:
Fatal error: Uncaught TypeError: mysqli_fetch_assoc(): Argument #1 ($result) must be of type mysqli_result
-MySQL: you can continue, in spite of not having data in the mysqli object.
james dot phx at gmail dot com ¶
13 years ago
IMPORTANT NOTE:
If you were used to using code like this:
<?php
while(false !== ($row = mysql_fetch_assoc($result)))
{
//...
}
?>
You must change it to this for mysqli:
<?php
while(null !== ($row = mysqli_fetch_assoc($result)))
{
//...
}
?>
The former will cause your script to run until max_execution_time is reached.
gilles dot falquet at unige dot ch ¶
7 years ago
Be careful when using fetch_assoc instead of fetch_row. If two columns of the result have the same column name, even if they are prefixed with different table names in the query, only one of them will be retained in the result. This is because the prefix is dropped (either by mysql or by this function)
For example if the query is
select p1.name, p2.name
from person p1, friend, person p2
where p1.id = friend.person1 and p2.id = friend.person2
the arrays returned by fetch_assoc will be of the form
{'name' => 'bob'}
{'name' => 'anna'}
and not (as expected)
{'p1.name' => 'bob', 'p2.name' => 'alice'}
{'p1.name' => 'anna', 'p2.name' => 'irla'}
Hesham Mohamed Sediek ¶
9 years ago
when you fetch the data from the query variable
and try to fetch it again in another part of the script
from the same query variable ,
when you try to echo all data you have fetched,
it will not echo the data you have used in the first fetch
(it will exceed the results you have used in the first fetch).......
Example :
<?php
$connect = new mysqli("localhost","root","root","elshamy")
or die (mysqli_error());
$query=$connect->query("SELECT * FROM users ORDER BY id ASC");
$first_fetch=$query->fetch_array(MYSQLI_ASSOC);
echo $first_fetch['id']."===>".$first_fetch['user_name']."\n--------------------\n";
while($row=$query->fetch_array(MYSQLI_ASSOC)){
/*it will exceed the first
id&user_name value that
you have use in the first fetch*/
echo $row['id']." ".$row['user_name']."<br/>";
}
?>
above example will echo :
1===>userA
------------------------
2===>userB
3===>userC
4===>userD
paul dot allsopp at inseego dot com ¶
7 years ago
The official example given here breaks a cardinal rule, and should be rectified.
while ($row = $result->fetch_assoc())...
...breaks the rule of "assignment in condition".
while (($x = $y->getZ()) !== false) or
while (($x = $y->getZ()) !== null)
...is the correct syntax.
Conditional statements should always check for a boolean
