 PHP : Function Reference : MySQL Functions : mysql_fetch_array
Example 1426. Query with aliased duplicate field names
SELECT table1.field AS foo, table2.field AS bar FROM table1, table2
<?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);
?>
<?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);
?>
<?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);
?>
joaocosta
You can make the function on the previous note slightly more efficient by using php's built in array_push function instead of a foreach loop:
<?php
function mysql_fetch_rowsarr($result, $numass=MYSQL_BOTH) {
$got=array();
mysql_data_seek($result, 0);
while ($row = mysql_fetch_array($result, $numass)) {
array_push($got, $row);
}
return $got;
}
?>
joelwan
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.
kunky
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.
yashiro
This is a simple function that outputs a String with a table with the name of fields and their respective values, pretty useful
u insert a result like this : $result = mysql_query("select * from table", $db)
/*Esta funcion genera automaticamente una tabla que muestra el resultado de un mysql_query,
basta con invocar la funcion y con echo imprimirla*/
function muestra_select($result){
$tabla = "\n\t".'<table border="2" align="center" cellpadding="2" cellspacing="2">'."\n";
for($i = 0; $i < mysql_num_fields($result); $i++){
$aux = mysql_field_name($result, $i);
$tabla .= "\t\t<th>".$aux."</th>\n";
}
while ($linea = mysql_fetch_array($result, MYSQL_ASSOC)) {
$tabla .= "\t\t<tr>\n";
foreach ($linea as $valor_col) {
$tabla .= "\t\t\t".'<td>'.$valor_col.'</td>'."\n";
}
$tabla .= "\t\t</tr>\n";
}
$tabla .= "\t</table>\n";
return $tabla;
}
joey
The issue of NULL fields seems to not be an issue anymore (as of 4.2.2 at least). mysql_fetch_* now seems to fully populate the array and put in entries with values of NULL when that is what the database returned. This is certainly the behaviour I expected, so I was concerned when i saw the notes here, but testing shows it does work the way I expected.
tilmauder
Remember that using a while() loop for traversing your result array is significantly slower than using a foreach() loop. Read the comments in the control structures section of this site for further details.
romans
Regarding duplicated field names in queries, I wanted some way to retrieve rows without having to use alias, so I wrote this class that returns rows as 2d-arrays
<?
$field = $drow['table']['column'];
?>
Here is the code:
<?
class mysql_resultset
{
var $results, $map;
function mysql_resultset($results)
{
$this->results = $results;
$this->map = array();
$index = 0;
while ($column = mysql_fetch_field($results))
{
$this->map[$index++] = array($column->table, $column->name);
}
}
function fetch()
{
if ($row = mysql_fetch_row($this->results))
{
$drow = array();
foreach ($row as $index => $field)
{
list($table, $column) = $this->map[$index];
$drow[$table][$column] = $row[$index];
}
return $drow;
}
else
return false;
}
}
?>
The class is initialized with a mysql_query result:
<?
$resultset = new mysql_resultset(mysql_query($sql));
?>
The constructor builds an array that maps each field index to a ($table, $column) array so we can use mysql_fetch_row and access field values by index in the fetch() method. This method then uses the map to build up the 2d-array.
An example:
<?
$sql =
"select orders.*, clients.*, productos.* ".
"from orders, clients, products ".
"where join conditions";
$resultset = new mysql_resultset(mysql_query($sql));
while ($drow = $resultset->fetch())
{
echo 'No.: '.$drow['orders']['number'].'
';
echo 'Client: '.$drow['clients']['name'].'
';
echo 'Product: '.$drow['products']['name'].'
';
}
?>
I hope others find this useful as it has been to me.
typer85
Please be advised that the resource result that you pass to this function can be thought of as being passed by reference because a resource is simply a pointer to a memory location.
Because of this, you can not loop through a resource result twice in the same script before resetting the pointer back to the start position.
For example:
----------------
<?php
// Assume We Already Queried Our Database.
// Loop Through Result Set.
while( $queryContent = mysql_fetch_row( $queryResult ) {
// Display.
echo $queryContent[ 0 ];
}
// We looped through the resource result already so the
// the pointer is no longer pointing at any rows.
// If we decide to loop through the same resource result
// again, the function will always return false because it
// will assume there are no more rows.
// So the following code, if executed after the previous code
// segment will not work.
while( $queryContent = mysql_fetch_row( $queryResult ) {
// Display.
echo $queryContent[ 0 ];
}
// Because $queryContent is now equal to FALSE, the loop
// will not be entered.
?>
----------------
The only solution to this is to reset the pointer to make it point at the first row again before the second code segment, so now the complete code will look as follows:
----------------
<?php
// Assume We Already Queried Our Database.
// Loop Through Result Set.
while( $queryContent = mysql_fetch_row( $queryResult ) {
// Display.
echo $queryContent[ 0 ];
}
// Reset Our Pointer.
mysql_data_seek( $queryResult );
// Loop Again.
while( $queryContent = mysql_fetch_row( $queryResult ) {
// Display.
echo $queryContent[ 0 ];
}
?>
----------------
Of course you would have to do extra checks to make sure that the number of rows in the result is not 0 or else mysql_data_seek itself will return false and an error will be raised.
Also please note that this applies to all functions that fetch result sets, including mysql_fetch_row, mysql_fetch_assos, and mysql_fetch_array.
ben
One of the most common mistakes that people make with this function, when using it multiple times in one script, is that they forget to use the mysql_data_seek() function to reset the internal data pointer.
When iterating through an array of MySQL results, e.g.
<?php
while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
foreach ($line as $col_value) {
echo $col_value . '<br />';
}
}
?>
the internal data pointer for the array is advanced, incrementally, until there are no more elements left in the array. So, basically, if you copy/pasted the above code into a script TWICE, the second copy would not create any output. The reason is because the data pointer has been advanced to the end of the $line array and returned FALSE upon doing so.
If, for some reason, you wanted to interate through the array a second time, perhaps grabbing a different piece of data from the same result set, you would have to make sure you call
<?php
mysql_data_seek($result, 0);
?>
This function resets the pointer and you can re-iterate through the $line array, again!
05-jun-2006 10:14
Note that as unlikely as it might be, queries like the following will mess up an array that is of result_type MYSQL_BOTH:
SELECT 'hello', 'world' AS '0';
john
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!
eddie
mob AT stag DOT ru has a nice function for getting simple arrays from MySQL but it has a serious bug. The MySQL link being set as an argument is NULL when no link is supplied meaning that you're passing NULL to the mysql funcctions as a link, which is wrong. I am not using multitple connections so I removed the link and using the global link. If you want to support multiple links check to see if its set first.
/*
* to support multiple links add the $link argument to function then
* test it before you use the link
*
* if(isset($link))
* if($err=mysql_errno($link))return $err;
* else
* if($err=mysql_errno())return $err;
*/
function mysql_fetch_all($query){
$r=@mysql_query($query);
if($err=mysql_errno())return $err;
if(@mysql_num_rows($r))
while($row=mysql_fetch_array($r))$result[]=$row;
return $result;
}
function mysql_fetch_one($query){
$r=@mysql_query($query);
if($err=mysql_errno())return $err;
if(@mysql_num_rows($r))
return mysql_fetch_array($r);
}
glenn dot hoeppner
Just another workaround for columns with duplicate names...
Modify your SQL to use the AS keyword.
Instead of:
$sql = "SELECT t1.cA, t2.cA FROM t1, t2 WHERE t1.cA = t2.cA";
Try:
$sql = "SELECT t1.cA AS foo1, t2.cA AS foo2 FROM t1, t2 WHERE t1.cA = t2.cA";
Then you can reference the results by name in the array:
$row[foo1], $row[foo2]
badulla
Just a real world example from a post below. I found it very useful for creating a table I needed from hundreds of proprietary colors. I added formatting so HTML source is clean and thought someone might be able to use or modify as I did.
<?php
// Query
$sql = "select colors_id, colors_type, colors_name, colors_number, R, G, B, colors_wetsample from products_colors where colors_type = 'Color Canvas' order by colors_number asc limit 40";
$result = mysql_query($sql ,$db);
// Change display for number of columns. Do not change cols as it is needed for counting.
$display = 7;
$cols = 0;
echo " <table border=0 cellpadding=1 cellspacing=0>\n";
while($C = mysql_fetch_array($result)){
if($cols == 0){
echo " <tr>\n";
}
// Display each cell here
echo " <td align=\"center\">\n"
. "\t<table border=0 cellspacing=0 cellpadding=0 width=\"100\" height=\"100\">\n"
. "\t <tr>\n"
. "\t <td height=\"85\" align=center valign=middle" . " "
. "style=" . "\"" . "background-color: rgb("
. $C['R'] . "," .$C['G'] . "," . $C['B'] . ")\"" . ">\n"
. "\t <span class=\"smcolor\">" . $C['colors_number'] . "</span>\n"
. "\t </td>\n"
. "\t </tr>\n"
. "\t <tr bgcolor=\"#ffffff\">\n"
. "\t <td align=center valign=middle>\n"
. "\t <span class=\"smcolor\">"
. "<a href=\"javascript:colorPop('../colors.php?colors_type=Color Canvas&colors_number="
. $C['colors_number'] . "')\"" . ">". $C['colors_name'] . "</span>\n"
. "\t </td>\n"
."\t </tr>\n"
. "\t</table>\n"
. " </td>\n";
$cols++;
if($cols == $display){
echo " </tr>\n";
$cols = 0;
}
}
// Display the correct HTML
if($cols != $display && $cols != 0){
$neededtds = $display - $cols;
for($i=0;$i<$neededtds;$i++){
echo " <td></td>\n";
}
echo " </tr>\n"
. " </table>\n";
} else {
echo " </table>\n";
}
?>
hdixonish
Just a fairly useful (to me at least!) "implementation" of mysql_fetch_assoc to stop the clobbering of identical column names and allow you to work out which table produced which result column when using a JOIN (or simple multiple-table) SQL query:
(assuming a live connection ...)
<?php
$sql = "SELECT a.*, b.* from table1 a, table2 b WHERE a.id=b.id"; // example sql
$r = mysql_query($sql,$conn);
if (!$r) die(mysql_error());
$numfields = mysql_num_fields($r);
$tfields = Array();
for ($i=0;$i<$numfields;$i++)
{
$field = mysql_fetch_field($r,$i);
$tfields[$i] = $field->table.'.'.$field->name;
}
while ($row = mysql_fetch_row($r))
{
$rowAssoc = Array();
for ($i=0;$i<$numfields;$i++)
{
$rowAssoc[$tfields[$i]] = $row[$i];
}
// do stuff with $rowAssoc as if it was $rowAssoc = mysql_fetch_assoc($r) you had used, but with table. prefixes
}
?>
let's you refer to $rowAssoc['a.fieldname'] for example.
[for real email addr, remove the ish]
tslukka
If you think MySQL (or other) database
handling is difficult and requires lot's of
code, I recommend that you try http://titaniclinux.net/daogen/
DaoGen is a program source code generator
that supports PHP and Java. It makes database
programming quick and easy. Generated sources
are released under GPL.
mjm
If you perform a SELECT query which returns different columns with duplicate names, like this:
--------
$sql_statement = "SELECT tbl1.colA, tbl2.colA FROM tbl1 LEFT JOIN tbl2 ON tbl1.colC = tbl2.colC";
$result = mysql_query($sql_statement, $handle);
$row = mysql_fetch_array($result);
--------
Then
$row[0] is equivalent to $row["colA"]
but
$row[1] is not equivalent to $row["colA"].
Moral of the story: You must use the numerical index on the result row arrays if column names are not unique, even if they come from different tables within a JOIN. This would render mysql_fetch_assoc() useless.
[Ed. note - or you could do the usual 'select tbl1.colA as somename, tbl2.colA as someothername. . .' which would obviate the problem. -- Torben]
sigit
if you have to use the field name with number like 1,2,..etc, it cause a problem when you fetch it with mysql_fetch_array.
An index array will contain a field name.
The solusion is:
1. Use mysql_fetch_assoc to escape the result to html;
2. Use alias and choose another name of field in mysql_query
mob
I wrote some utility functions to improve usability and readability, and use them everywhere in my code. I suppose they can help.
function mysql_fetch_all($query,$MySQL=NULL){
$r=@mysql_query($query,$MySQL);
if($err=mysql_errno($MySQL))return $err;
if(@mysql_num_rows($r))
while($row=mysql_fetch_array($r))$result[]=$row;
return $result;
}
function mysql_fetch_one($query,$MySQL=NULL){
$r=@mysql_query($query,$MySQL);
if($err=mysql_errno($MySQL))return $err;
if(@mysql_num_rows($r))
return mysql_fetch_array($r);
}
Example use:
if(is_array($rows=mysql_fetch_all("select * from sometable",$MySQL))){
//do something
}else{
if(!is_null($rows)) die("Query failed!");
}
info
I think using a for loop to display fetched rows from a table is more convenient than a while loop, since one have directely access to the record number:
$reclist = mysql_query("SELECT field FROM table",$db)
or die(mysql_errno()." : ".mysql_error());
for ($j=0; $rec=mysql_fetch_array($reclist); $j++){
printf("%s - %s
\n",$j,$rec["field"]);
}
Hope this is usefull. Ali
some
I never had so much trouble with null fields but it's to my understanding that extract only works as expected when using an associative array only, which is the case with mysql_fetch_assoc() as used in the previous note.
However a mysql_fetch_array will return field values with both the numerical and associative keys, the numerical ones being those extract() can't handle very well.
You can prevent that by calling mysql_fetch_array($result,MYSQL_ASSOC) which will return the same result as mysql_fetch_assoc and is extract() friendly.
dkantha
I did find 'jb at stormvision's' code useful above, but instead of the number of rows you need the number of fields; otherwise you get an error.
So, it should read like the following:
$result=mysql_query("select * from mydata order by 'id'")or die('died');
$num_fields = mysql_num_fields($result);
$j=0;
$x=1;
while($row=mysql_fetch_array($result)){
for($j=0;$j<$num_fields;$j++){
$name = mysql_field_name($result, $j);
$object[$x][$name]=$row[$name];
}$x++;
}
For Later in the script you may use the below array to gain access to your data
$i=1;
$ii=count($object); //quick access function
for($i=1;$i<=$ii;$i++){
echo $object[$i]['your_field_name'];
}
I have tested this in my apps and it works great! :-)
techquest
Hi to enumerate a result set with out worrying about null values just use below code.
while($myrow = mysql_fetch_row($result))
{
print " <tr> ";
for($x=0; $x <= count($myrow); $x++)
{
print "<td>myrow[$x]</td>";
}
print "</tr>";
}
[ed note: tidied code so it actually works]
tim
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
barbieri
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.
hanskrentel
for the problem with fields containing null values in an associated array, feel free to use this function. i've got no more problems with it, just drop it in your script:
/*
* mysql_fetch_array_nullsafe
*
*
* get a result row as an enumerated and associated array
* ! nullsafe !
*
* parameter: $result
* $result: valid db result id
*
* returns: array | false (mysql:if there are any more rows)
*
*/
function mysql_fetch_array_nullsafe($result) {
$ret=array();
$num = mysql_num_fields($result);
if ($num==0) return $ret;
$fval = mysql_fetch_row ($result);
if ($fval === false) return false;
$i=0;
while($i<$num)
{
$fname[$i] = mysql_field_name($result,$i);
$ret[$i] = $fval[$i]; // enum
$ret[''.$fname[$i].''] = $fval[$i]; // assoc
$i++;
}
return $ret;
}
robjohnson
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.
juancri
An example with mysql_fetch_array():
$result = mysql_query("SELECT name FROM table WHERE id=8");
$array = mysql_fetch_array($result);
$array will be:
array ([0] => "John", ['name'] => "John")
Then you can access to the results:
echo "The name is " . $array[0];
// or
echo "The name is " . $array['name'];
But the array is not referential. $array[0] is not a reference to $array['name'] or $array['name'] to $array[0], they are not relationed between. Because of that, the system will use excesive memory. With large columns, try to use mysql_fetch_assoc() or mysql_fetch_row() only.
andrea
alternative mysql_fetch_all
// array mysql_fetch_all(query:resource [, kind:string (default:'assoc' | 'row')])
function mysql_fetch_all($query, $kind = 'assoc') {
$result = array();
$kind = $kind === 'assoc' ? $kind : 'row';
eval('while(@$r = mysql_fetch_'.$kind.'($query)) array_push($result, $r);');
return $result;
}
// Example
$query = mysql_query($myquery) or die(mysql_error());
$result = mysql_fetch_all($query);
echo '<pre>'.print_r($result, true).'</pre>';
joshmish
A simple function that returns the next auto index. I recommend you use a unique id and not a relative row index, but if the need arises, here's how to get that id before you INSERT without the error-prone MAX(id) approach.
<?php
function nextautoindex ($table) {
$res=mysql_query("SHOW TABLE STATUS");
if (@mysql_num_rows($res)>0) { while ($row = @mysql_fetch_array($res, MYSQL_ASSOC)) {
if ($table == $row["name"]) return $row["Auto_increment"];
}}
return false;
}
/* Example usage:
$newID = nextautoindex("user"); // output: 12
// Now you can insert multiple related records without guessing the id
*/
?>
devinivy
<?php
function mysql_fetch_rowsarr($result, $numass=MYSQL_BOTH) {
$i=0;
$keys=array_keys(mysql_fetch_array($result, $numass));
mysql_data_seek($result, 0);
while ($row = mysql_fetch_array($result, $numass)) {
foreach ($keys as $speckey) {
$got[$i][$speckey]=$row[$speckey];
}
$i++;
}
return $got;
}
?>
Ever found it a bit of a pain to use mysql_fetch_array()? I find this function much easier to receive data, and to be in a more accessible manner when accessing various data from several rows. It is practical when more than one row is expected to be returned from a SELECT query. It returns a 2-dimensional array in the form of $arr[number_row_returned][column_desired]. So, if there is some column 'password', and you want the password from the third returned row:
<?php
$result = mysql_query($query);
$arr = mysql_fetch_rowsarr($result);
$password = $arr[2]['password'];
?>
The function also has the ability to return the columns numerically, associatively, or both, just as mysql_fetch_array() does. It uses MYSQL_NUM, MYSQL_ASSOC, and MYSQL_BOTH (MYSQL_BOTH being the default)- exactly like mysql_fetch_array(). So, if the column 'password' is the 4th column which is returned in the query, then password of the 1st returned row could be accessed like so:
<?php
$arr = mysql_fetch_rowsarr($result, MYSQL_NUM);
$password = $arr[0][3];
?>
I hope you find it useful!
-Dan
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