mysql_fetch_array
(PHP 4, PHP 5, PECL mysql:1.0)
mysql_fetch_array — Обрабатывает ряд результата запроса, возвращая ассоциативный массив, численный массив или оба.
Описание
Возвращает массив с обработанным рядом результата запроса, или FALSE, если рядов больше нет.
mysql_fetch_array() расширенная версия функции mysql_fetch_row(). В дополнении к хранению значений в массиве с численными индексами, функция возвращает значения в массиве с индексами по названию колонок.
Если несколько колонок в результате будут иметь одинаковые названия, последняя колонка будет возвращена. Чтобы получить доступ к первым, используйте численные индексы массива или алиасы в запросе. В случае алиасов используйте именно их -- вы не сможете использовать настоящие имена колонок, как например не сможете использовать 'field' в нижеописанном примере.
Пример #1 Запрос с дублирующимися именами колонок
select table1.field as foo, table2.field as bar from table1, table2
Важно заметить, что mysql_fetch_array() работает НЕ медленнее, чем mysql_fetch_row(), в то время, как предоставляет более удобный доступ к данным.
Второй опциональный аргумент result_type в функции mysql_fetch_array() -- константа и может принимать следующие значения: MYSQL_ASSOC, MYSQL_NUM и MYSQL_BOTH. Эта возможность добавлена в PHP 3.0.7. Значением по умолчанию является: MYSQL_BOTH.
Используя MYSQL_BOTH, вы получите массив, состоящий как из ассоциативных индексов, так и из численных. MYSQL_ASSOC вернёт только ассоциативные соответствия (аналогично функции mysql_fetch_assoc() и MYSQL_NUM только численные (аналогично функции mysql_fetch_row()).
Замечание: Имена полей, возвращаемые этой функцией, регистро-зависимы.
Пример #2 mysql_fetch_array() с MYSQL_NUM
<?php
mysql_connect("localhost", "mysql_user", "mysql_password") or
die("Could not connect: " . mysql_error());
mysql_select_db("mydb");
$result = mysql_query("SELECT id, name FROM mytable");
while ($row = mysql_fetch_array($result, MYSQL_NUM)) {
printf ("ID: %s Name: %s", $row[0], $row[1]);
}
mysql_free_result($result);
?>
Пример #3 mysql_fetch_array() с MYSQL_ASSOC
<?php
mysql_connect("localhost", "mysql_user", "mysql_password") or
die("Could not connect: " . mysql_error());
mysql_select_db("mydb");
$result = mysql_query("SELECT id, name FROM mytable");
while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
printf ("ID: %s Name: %s", $row["id"], $row["name"]);
}
mysql_free_result($result);
?>
Пример #4 mysql_fetch_array() с MYSQL_BOTH
<?php
mysql_connect("localhost", "mysql_user", "mysql_password") or
die("Could not connect: " . mysql_error());
mysql_select_db("mydb");
$result = mysql_query("SELECT id, name FROM mytable");
while ($row = mysql_fetch_array($result, MYSQL_BOTH)) {
printf ("ID: %s Name: %s", $row[0], $row["name"]);
}
mysql_free_result($result);
?>
См. также mysql_fetch_row() и mysql_fetch_assoc().
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Коментарии
I never had so much trouble with null fields but it's to my understanding that extract only works as expected when using an associative array only, which is the case with mysql_fetch_assoc() as used in the previous note.
However a mysql_fetch_array will return field values with both the numerical and associative keys, the numerical ones being those extract() can't handle very well.
You can prevent that by calling mysql_fetch_array($result,MYSQL_ASSOC) which will return the same result as mysql_fetch_assoc and is extract() friendly.
Here is a suggestion to workaround the problem of NULL values:
// get associative array, with NULL values set
$record = mysql_fetch_array($queryID,MYSQL_ASSOC);
// set number indices
if(is_array($record))
{
$i = 0;
foreach($record as $element)
$record[$i++] = $element;
}
This way you can access $result array as usual, having NULL fields set.
Benchmark on a table with 38567 rows:
mysql_fetch_array
MYSQL_BOTH: 6.01940000057 secs
MYSQL_NUM: 3.22173595428 secs
MYSQL_ASSOC: 3.92950594425 secs
mysql_fetch_row: 2.35096800327 secs
mysql_fetch_assoc: 2.92349803448 secs
As you can see, it's twice as effecient to fetch either an array or a hash, rather than getting both. it's even faster to use fetch_row rather than passing fetch_array MYSQL_NUM, or fetch_assoc rather than fetch_array MYSQL_ASSOC. Don't fetch BOTH unless you really need them, and most of the time you don't.
Try Php Object Generator: http://www.phpobjectgenerator.com
It's kind of similar to Daogen, which was suggested in one of the comments above, but simpler and easier to use.
Php Object Generator generates the Php Classes for your Php Objects. It also provides the database class so you can focus on more important aspects of your project. Hope this helps.
This is very useful when the following query is used:
`SHOW TABLE STATUS`
Different versions of MySQL give different responses to this.
Therefore, it is better to use mysql_fetch_array() because the numeric references given my mysql_fetch_row() give very different results.
Here's a quick way to duplicate or clone a record to the same table using only 4 lines of code:
// first, get the highest id number, so we can calc the new id number for the dupe
// second, get the original entity
// third, increment the dupe record id to 1 over the max
// finally insert the new record - voila - 4 lines!
$id_max = mysql_result(mysql_query("SELECT MAX(id) FROM table_name"),0,0) or die("Could not execute query");
$entity = mysql_fetch_array(mysql_query("SELECT * FROM table." WHERE id='$id_original'),MYSQL_ASSOC) or die("Could not select original record"); // MYSQL_ASSOC forces a purely associative array and blocks twin key dupes, vitally, it brings the keys out so they can be used in line 4
$entity["id"]=$id_max+1;
mysql_query("INSERT INTO it_pages (".implode(", ",array_keys($Entity)).") VALUES ('".implode("', '",array_values($Entity))."')");
Really struggled in cracking this nut - maybe there's an easier way out there? Thanks to other posters for providing inspiration. Good luck - Tim
my main purpose was to show the fetched array into a table, showing the results side by side instead of underneath each other, and heres what I've come up with.
just change the $display number to however many columns you would like to have, just dont change the $cols number or you might run into some problems.
<?php
$display = 4;
$cols = 0;
echo "<table>";
while($fetched = mysql_fetch_array($result)){
if($cols == 0){
echo "<tr>\n";
}
// put what you would like to display within each cell here
echo "<td>".$fetched['id']."<br />".$fetched['name']."</td>\n";
$cols++;
if($cols == $display){
echo "</tr>\n";
$cols = 0;
}
}
// added the following so it would display the correct html
if($cols != $display && $cols != 0){
$neededtds = $display - $cols;
for($i=0;$i<$neededtds;$i++){
echo "<td></td>\n";
}
echo "</tr></table>";
} else {
echo "</table>";
}
?>
Hopefully this will save some of you a lot of searching.
any kind of improvements on this would be awesome!
I have found a way to put all results from the select query in an array in one line.
// Read records
$result = mysql_query("SELECT * FROM table;") or die(mysql_error());
// Put them in array
for($i = 0; $array[$i] = mysql_fetch_assoc($result); $i++) ;
// Delete last empty one
array_pop($array);
You need to delete the last one because this will always be empty.
By this you can easily read the entire table to an array and preserve the keys of the table columns. Very handy.
As opposite of mysql_fetch_array:
<?php
function mysql_insert_array ($my_table, $my_array) {
$keys = array_keys($my_array);
$values = array_values($my_array);
$sql = 'INSERT INTO ' . $my_table . '(' . implode(',', $keys) . ') VALUES ("' . implode('","', $values) . '")';
return(mysql_query($sql));
}
#http://www.weberdev.com/get_example-4493.html
?>
I ran into troubles with MySQL NULL values when I generated dynamic queries and then had to figure out whether my resultset contained a specific field.
First instict was to use isset() and is_null(), but these function will not behave as you probably expect.
I ended up using array_key_exists, as it was the only function that could tell me whether the key actually existed or not.
<?php
$row = mysql_fetch_assoc(mysql_query("SELECT null as a"));
var_dump($row); //array(1) { ["a"]=> NULL }
var_dump(isset($row['a'])); //false
var_dump(isset($row['b'])); //false
var_dump(is_null($row['a'])); //true
var_dump(is_null($row['b'])); //true + throws undefined index notice
var_dump(array_key_exists('a', $row)); // true
var_dump(array_key_exists('b', $row)); // false
?>
If I use
<?php
while($r[]=mysql_fetch_array($sql));
?>
so in array $r is one more entry then rows returned from the database.
<?php
while($r[]=mysql_fetch_array($sql));
?>
Yes, that will generate a dummy array element containing the false of the final mysql_fetch_array. You should either truncate the array or (more sensibly in my mind) check that the result of mysql_fetch_array is not false before adding it to the array.