mysqli_result::fetch_array

mysqli_fetch_array

(PHP 5, PHP 7, PHP 8)

mysqli_result::fetch_array -- mysqli_fetch_array — Fetch the next row of a result set as an associative, a numeric array, or both

Descrizione

Stile orientato agli oggetti

public mysqli_result::fetch_array(int $mode = MYSQLI_BOTH): array|null|false

Stile procedurale

mysqli_fetch_array(mysqli_result $result, int $mode = MYSQLI_BOTH): array|null|false

Fetches one row of data from the result set and returns it as an array. Each subsequent call to this function will return the next row within the result set, or null if there are no more rows.

In addition to storing the data in the numeric indices of the result array, this function can also store the data in associative indices by using the field names of the result set as keys.

If two or more columns of the result have the same name, the last column will take precedence and overwrite any previous data. To access multiple columns with the same name, the numerically indexed version of the row must be used.

Nota: I nomi dei campi restituiti da questa funzione sono case-sensitive.

Nota: Questa funzione imposta i campio NULL al valore PHP null.

Elenco dei parametri

result

Solo nello stile procedurale: un identificatore di resultset restituito da mysqli_query(), mysqli_store_result() o mysqli_use_result().

mode

This optional parameter is a constant indicating what type of array should be produced from the current row data. The possible values for this parameter are the constants MYSQLI_ASSOC, MYSQLI_NUM, or MYSQLI_BOTH.

By using the MYSQLI_ASSOC constant this function will behave identically to the mysqli_fetch_assoc(), while MYSQLI_NUM will behave identically to the mysqli_fetch_row() function. The final option MYSQLI_BOTH will create a single array with the attributes of both.

Valori restituiti

Returns an array representing the fetched row, null if there are no more rows in the result set, o false in caso di fallimento.

Esempi

Example #1 mysqli_result::fetch_array() example

Stile orientato agli oggetti

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

$query = "SELECT Name, CountryCode FROM City ORDER BY ID LIMIT 3";
$result = $mysqli->query($query);

/* numeric array */
$row = $result->fetch_array(MYSQLI_NUM);
printf("%s (%s)\n", $row[0], $row[1]);

/* associative array */
$row = $result->fetch_array(MYSQLI_ASSOC);
printf("%s (%s)\n", $row["Name"], $row["CountryCode"]);

/* associative and numeric array */
$row = $result->fetch_array(MYSQLI_BOTH);
printf("%s (%s)\n", $row[0], $row["CountryCode"]);

Stile procedurale

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = mysqli_connect("localhost", "my_user", "my_password", "world");

$query = "SELECT Name, CountryCode FROM City ORDER by ID LIMIT 3";
$result = mysqli_query($mysqli, $query);

/* numeric array */
$row = mysqli_fetch_array($result, MYSQLI_NUM);
printf("%s (%s)\n", $row[0], $row[1]);

/* associative array */
$row = mysqli_fetch_array($result, MYSQLI_ASSOC);
printf("%s (%s)\n", $row["Name"], $row["CountryCode"]);

/* associative and numeric array */
$row = mysqli_fetch_array($result, MYSQLI_BOTH);
printf("%s (%s)\n", $row[0], $row["CountryCode"]);

The above examples will output something similar to:

Kabul (AFG)
Qandahar (AFG)
Herat (AFG)

Vedere anche:

mysqli_fetch_assoc() - Fetch the next row of a result set as an associative array
mysqli_fetch_column() - Fetch a single column from the next row of a result set
mysqli_fetch_row() - Fetch the next row of a result set as an enumerated array
mysqli_fetch_object() - Fetch the next 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

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User Contributed Notes 4 notes

down

Jammerx2 ¶

14 years ago


Putting multiple rows into an array:

<?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 LIMIT 3";
$result = $mysqli->query($query);

while($row = $result->fetch_array())
{
$rows[] = $row;
}

foreach($rows as $row)
{
echo $row['CountryCode'];
}

/* free result set */
$result->close();

/* close connection */
$mysqli->close();
?>

down

-2

Duncan ¶

11 years ago


Note that the array returned contains only strings.

E.g. when a MySQL field is an INT you may expect the field to be returned as an integer, however all fields are simply returned as strings.

What this means: use double-equals not triple equals when comparing numbers.

<?php
print $array_from_mysqli_fetch_array['id'] == 1 ? "true" : "false"; // true
print $array_from_mysqli_fetch_array['id'] === 1 ? "true" : "false"; // false
?>

down

-18

meaje at msn dot com ¶

7 years ago


Please note that under PHP 5.x there appears to be a globally defined variable MYSQL_ASSOC, MYSQL_NUM, or MYSQL_BOTH which is the equivalent of MYSQLI_ASSOC, MYSQLI_NUM, or MYSQLI_BOTH!!! Yet under PHP 7.x this is NOT the case and will cause a failure in trying to retrieve the result set!

This can cause severe headaches when trying to find out why you are getting the error: 
 - mysqli_result::fetch_array() expects parameter 1 to be integer, string given in 'Filename' on line 'XX'

down

-53

ahouston at gmail dot com ¶

13 years ago


Here is a function to return an associative array with multiple columns as keys to the array.

This is a rough approximation of the perl DBI->fetchall_hashref function - something I find myself using quite a bit.

Given a simple mySQL table:

mysql> select * from city;
+----------------+----------------+------------------+------------+
| country        | region         | city             | hemisphere |
+----------------+----------------+------------------+------------+
| South Africa   | KwaZulu-Natal  | Durban           | South      |
| South Africa   | Gauteng        | Johannesburg     | South      |
| South Africa   | Gauteng        | Tshwane          | South      |
| South Africa   | KwaZulu-Natal  | Pietermaritzburg | South      |
| United Kingdom | Greater London | City of London   | North      |
| United Kingdom | Greater London | Wimbledon        | North      |
| United Kingdom | Lancashire     | Liverpool        | North      |
| United Kingdom | Lancashire     | Manchester       | North      |
+----------------+----------------+------------------+------------+

*Note* - this is a simple function that makes no attempt to keep multiple values per key, so you need to specify all the unique keys you require.

<?php

        $link = mysqli_connect("localhost", "username", "password", "test");
        $result = mysqli_query($link, "select * from city");
        $results_arr = fetch_all_assoc($result,array('hemisphere','country','region','city'));

function fetch_all_assoc(& $result,$index_keys) {

  // Args :    $result = mysqli result variable (passed as reference to allow a free() at the end
  //           $indexkeys = array of columns to index on
  // Returns : associative array indexed by the keys array

  $assoc = array();             // The array we're going to be returning

  while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {

        $pointer = & $assoc;            // Start the pointer off at the base of the array

        for ($i=0; $i<count($index_keys); $i++) {
        
                $key_name = $index_keys[$i];
                if (!isset($row[$key_name])) {
                        print "Error: Key $key_name is not present in the results output.\n";
                        return(false);
                }

                $key_val= isset($row[$key_name]) ? $row[$key_name]  : "";
        
                if (!isset($pointer[$key_val])) {               

                        $pointer[$key_val] = "";                // Start a new node
                        $pointer = & $pointer[$key_val];                // Move the pointer on to the new node
                }
                else {
                        $pointer = & $pointer[$key_val];            // Already exists, move the pointer on to the new node
                }

        } // for $i

        // At this point, $pointer should be at the furthest point on the tree of keys
        // Now we can go through all the columns and place their values on the tree
        // For ease of use, include the index keys and their values at this point too

        foreach ($row as $key => $val) {
                        $pointer[$key] = $val;
        }

  } // $row

  /* free result set */
  $result->close();

  return($assoc);               
}

?>

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