mysql_fetch_assoc
Simple function to display all data in a query...
function dumpquery($query) {
$numfields = mysql_num_fields($query);
echo '<table border="1" bgcolor="white"><tr>';
for ($i = 0; $i<$numfields; $i += 1) {
$field = mysql_fetch_field($query, $i);
echo '<th>' . $field->name . '</th>';
}
echo '</tr>';
while ($fielddata = mysql_fetch_array($query)) {
echo '<tr>';
for ($i = 0; $i<$numfields; $i += 1) {
$field = mysql_fetch_field($query, $i);
echo '<td>' . $fielddata[$field->name] . '</td>';
}
echo '</tr>';
}
echo '</table>';
}
mysql_fetch_field
(PHP 4, PHP 5)
mysql_fetch_field — 결과로 부터 컬럼 정보를 얻어서 객체형태로 반환
설명
object mysql_fetch_field
( resource $result
[, int $field_offset
] )
필드 정보를 포함하는 객체를 반환한다. 이 함수는 질의 결과에서 필드에 대한 정보를 얻는 데 사용할 수 있다.
인수
- result
-
mysql_query() 호출을 통한 결과 resource.
- field_offset
-
숫자형 필드 위치. 필드 위치를 지정하지 않으면, 이 함수로 아직 조회되지 않은 다음 필드가 조회된다. field_offset은 0부터 시작한다.
반환값
필드 정보를 포함하는 object를 반환한다. 객체의 특성은 다음과 같다:
- name - 컬럼명
- table - 컬럼이 속하는 테이블 이름
- def - 컬럼 기본값
- max_length - 컬럼의 최대 길이
- not_null - 컬럼이 NULL이 될 수 없다면 1
- primary_key - 컬럼이 기본키이면 1
- unique_key - 컬럼이 유일키이면 1
- multiple_key - 컬럼이 비-유일키이면 1
- numeric - 컬럼이 숫자형이면 1
- blob - 컬럼이 BLOB이면 1
- type - 컬럼의 형태
- unsigned - 컬럼이 unsigned이면 1
- zerofill - 컬럼이 zerofill이면 1
예제
Example #1 mysql_fetch_field() 예제
<?php
$conn = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$conn) {
die('Could not connect: ' . mysql_error());
}
mysql_select_db('database');
$result = mysql_query('select * from table');
if (!$result) {
die('Query failed: ' . mysql_error());
}
/* get column metadata */
$i = 0;
while ($i < mysql_num_fields($result)) {
echo "Information for column $i:<br />\n";
$meta = mysql_fetch_field($result, $i);
if (!$meta) {
echo "No information available<br />\n";
}
echo "<pre>
blob: $meta->blob
max_length: $meta->max_length
multiple_key: $meta->multiple_key
name: $meta->name
not_null: $meta->not_null
numeric: $meta->numeric
primary_key: $meta->primary_key
table: $meta->table
type: $meta->type
default: $meta->def
unique_key: $meta->unique_key
unsigned: $meta->unsigned
zerofill: $meta->zerofill
</pre>";
$i++;
}
mysql_free_result($result);
?>
주의
Note: 이 함수가 반환하는 필드 이름은 대소문자를 구별합니다.
add a note
User Contributed Notes
mysql_fetch_field
Daniel B
26-Mar-2012 02:56
lucien at ocia dot nl
04-Feb-2012 01:08
Performance Notes!
I used this script for testing, the table has 26 colums.
<?php
$t_start = microtime(true);
$sql = mysql_query("SELECT * FROM `table` LIMIT 1") or trigger_error(mysql_error(), E_USER_WARNING);
for ($i = 0; $i < mysql_num_fields($sql); $i++) {
$meta = mysql_fetch_field($sql, $i);
echo "Information for column ".$meta->name.":\n";
echo
"\tblob: $meta->blob
\tmax_length: $meta->max_length
\tmultiple_key: $meta->multiple_key
\tname: $meta->name
\tnot_null: $meta->not_null
\tnumeric: $meta->numeric
\tprimary_key: $meta->primary_key
\ttable: $meta->table
\ttype: $meta->type
\tunique_key: $meta->unique_key
\tunsigned: $meta->unsigned
\tzerofill: $meta->zerofill
";
}
$t_stop = microtime(true);
$t_proc = $t_stop - $t_start;
echo "processing time query 1: ".number_format($t_proc * 1000, 3)." ms\n";
unset($t_start);
unset($t_stop);
unset($t_proc);
$t_start = microtime(true);
$sql = mysql_query("DESCRIBE `table`");
while ($res = mysql_fetch_array($sql, MYSQL_ASSOC)) {
print_r($res);
}
$t_stop = microtime(true);
$t_proc = $t_stop - $t_start;
echo "processing time query 2: ".number_format($t_proc * 1000, 3)." ms\n";
?>
Query 1 => 0.444 ms
Query 2 => 1.146 ms
So for easy usage, Query 2 is advised... But if your a performance-geek, you should use Query 1.
eviltofu at gmail dot com
08-Jul-2011 05:58
MYSQLI_TYPE_BLOB indicates the field is a BLOB or a TEXT. I think you would need to check the blob value. If its true then it's a BLOB, otherwise it's a TEXT. Can someone confirm?
Jonathan
30-Jul-2010 05:45
It should be noted that the primary_key member variable is only set to 1 if the primary key on the table is only on that 1 field. If you have a table that has a multiple column primary key, then you will not get what you might expect.
For example:
CREATE TABLE `line_item_table` (
`liForeignKey1` int(11) unsigned not null,
`liForeignKey2` int(11) unsigned not null,
PRIMARY KEY (`liForeignKey1`, `liForeignKey2`)
) ENGINE=MyISAM;
While you might expect that primary_key == 1 for both columns; var_dump() will show you that you get the following for both fields:
["primary_key"]=>int(0)
This is as of PHP 5.2.13 and MySQL 5.0.51
mewsterus at yahoo dot com
07-Jul-2009 11:18
A nice function to return an array of all fields for a particular table. I've added a few very useful properties to the spec:
'len', which is supplied by the mysql_field_len() function.
'definition', which is a column_definition which could be used to initialize the table.
'auto_increment', which is 1 if the field is auto_increment.
<?php
function mysql_fetch_fields($table) {
// LIMIT 1 means to only read rows before row 1 (0-indexed)
$result = mysql_query("SELECT * FROM $table LIMIT 1");
$describe = mysql_query("SHOW COLUMNS FROM $table");
$num = mysql_num_fields($result);
$output = array();
for ($i = 0; $i < $num; ++$i) {
$field = mysql_fetch_field($result, $i);
// Analyze 'extra' field
$field->auto_increment = (strpos(mysql_result($describe, $i, 'Extra'), 'auto_increment') === FALSE ? 0 : 1);
// Create the column_definition
$field->definition = mysql_result($describe, $i, 'Type');
if ($field->not_null && !$field->primary_key) $field->definition .= ' NOT NULL';
if ($field->def) $field->definition .= " DEFAULT '" . mysql_real_escape_string($field->def) . "'";
if ($field->auto_increment) $field->definition .= ' AUTO_INCREMENT';
if ($key = mysql_result($describe, $i, 'Key')) {
if ($field->primary_key) $field->definition .= ' PRIMARY KEY';
else $field->definition .= ' UNIQUE KEY';
}
// Create the field length
$field->len = mysql_field_len($result, $i);
// Store the field into the output
$output[$field->name] = $field;
}
return $output;
}
// Example:
mysql_connect('localhost', 'user', 'pass');
mysql_select_db('database');
$fields = mysql_fetch_fields('table');
foreach ($fields as $key => $field) {
echo $field->name . ' ' . $field->definition . "\n";
}
// May output:
// field1 char(8)
// field2 int PRIMARY KEY
// field3 int AUTO_INCREMENT UNIQUE KEY
// field4 mediumtext NOT NULL DEFAULT 'I\'m a little teapot'
?>
TALU
04-Feb-2009 08:16
XML generation.
Bit of a security risk allowing parameters to select db and table on live server (unless user is restricted or replace the $_GET with fixed value.)
Outputs xml with standard format for <config> part to generate forms in flash.
<?php
//
// makeXML.php?db=dbname&table=tablename
//
set_time_limit(300);
$host = "localhost";
$user = "root";
$password = "root";
$database = $_GET['db'];
$table = $_GET['table'];
mysql_connect($host,$user,$password);
@mysql_select_db($database) or die( "Unable to select database");
$querytext="SELECT * FROM ".$table;
$result=mysql_query($querytext);
if ($result){
$num=mysql_num_rows($result);
}else{
$num=0;
}
?>
<?php
header('Content-Type: text/xml');
echo "<?xml version='1.0'?>";
if ($num > 0){
?>
<<?php echo $table?>>
<config>
<?php
// Display number of fields
echo "<numFields>".mysql_num_fields($result)."</numFields>";
$i = 0;
$primaryKey = "";
$nameArray = array();
$maxLengthArray = array();
$typeArray = array();
while ($i < mysql_num_fields($result)) {
$meta = mysql_fetch_field($result, $i);
$nameArray[$i] = $meta->name;
$maxLengthArray[$i] = $meta->max_length;
$typeArray[$i] = $meta->type;
if ($meta->primary_key){
$primaryKey = $meta->name;
}
$i++;
}
$i = 0;
echo "<fieldNames>";
while ($i < count($nameArray)) {
echo "<field".$i.">".$nameArray[$i]."</field".$i.">";
$i++;
}
echo "</fieldNames>";
$i = 0;
echo "<fieldMaxLength>";
while ($i < count($maxLengthArray)) {
echo "<field".$i.">".$maxLengthArray[$i]."</field".$i.">";
$i++;
}
echo "</fieldMaxLength>";
$i = 0;
echo "<fieldType>";
while ($i < count($typeArray)) {
echo "<field".$i.">".$typeArray[$i]."</field".$i.">";
$i++;
}
echo "</fieldType>";
?>
<primaryKey><?php echo $primaryKey?></primaryKey>
<numRecords><?php echo $num?></numRecords>
</config>
<?php
$i=0;
while ($i < $num) {
$ID=mysql_result($result,$i,"ID");
$value=mysql_result($result,$i,"value");
$title=mysql_result($result,$i,"title");
$description=mysql_result($result,$i,"description");
?>
<row>
<ID><?php echo $ID?></ID>
<weighting><?php echo $value?></weighting>
<title><?php echo $title?></title>
<description><?php echo $description?></description>
</row>
<?php
$i = $i + 1;
}
?>
</<?php echo $table?>>
<?php
}
?>
php [spat] hm2k.org
04-Nov-2008 03:22
An improvement on the earlier mysql_column_exists function.
<?php
function mysql_column_exists($table_name, $column_name, $link=false) {
$result = @mysql_query("SHOW COLUMNS FROM $table_name LIKE '$column_name'", $link);
return (mysql_num_rows($result) > 0);
}
?>
jorachim at geemail dot com
25-Sep-2008 01:09
If you want the fields in a table, a simple DESCRIBE query will work:
<?php
$query ="DESCRIBE Users";
$result = mysql_query($query);
echo "<ul>";
while($i = mysql_fetch_assoc($result))
echo "<li>{$i['Field']}</li>";
echo "</ul>";
?>
Should do the trick.
david at vitam dot be
10-Jun-2008 05:57
A little function to help coders to distinct the tablename from a multiselect query where some fields has the same name in differents tables.
<?php
public function sql($sql) {
$T_Return=array();
$result=@mysql_query($sql);
$i=0;
while ($i < mysql_num_fields($result)) {
$fields[]=mysql_fetch_field($result, $i);
$i++;
}
while ($row=mysql_fetch_row($result)) {
$new_row=array();
for($i=0;$i<count($row); $i++) {
$new_row[ $fields[$i]->table][$fields[$i]->name]=$row[$i];
}
$T_Return[]=$new_row;
}
return $T_Return;
}
?>
dheep
03-Jun-2008 08:56
Simple PHP script for displaying the field names. Presuming the database is seleected already.
<?php
$sql = "SELECT * FROM table_name;";
$result = mysql_query($sql);
$i = 0;
while($i<mysql_num_fields($result))
{
$meta=mysql_fetch_field($result,$i);
echo $i.".".$meta->name."<br />";
$i++;
}
?>
OUTPUt:
0.id
1.todo
2.due date
3.priority
4.type
5.status
6.notes
hope this is useful.
Nick Baicoianu
15-Sep-2005 11:18
Be sure to note that $max_length is the length of the longest value for that field in the returned dataset, NOT the maximum length of data that column is designed to hold.
php at brayra dot com
21-Mar-2002 04:09
I needed to get the field information and the enum/set values. Here is the function I created to expand the object returned by mysql_fetch_field. I also, decided to return all the fields for a table in an array of field objects by "name" and position much like mysql_fetch_array does.
You could test it by using:
<?php
$myfields = GetFieldInfo('test_table');
print "<pre>";
print_r($myfields);
print "</pre>";
?>
The field objects now have 'len', 'values' and 'flags' parameters.
NOTE: 'values' only has data for set and enum fields.
<?php
//This assumes an open database connection
//I also use a constant DB_DB for current database.
function GetFieldInfo($table)
{
if($table == '') return false;
$fields = mysql_list_fields(DB_DB, $table);
if($fields){
$columns = mysql_query('show columns from ' . $table);
if($columns){
$num = mysql_num_fields($fields);
for($i=0; $i < $num; ++$i){
$column = mysql_fetch_array($columns);
$field = mysql_fetch_field($fields, $i);
$flags = mysql_field_flags($fields, $i);
if($flags == '') $flags=array();
else $flags = explode(' ',$flags);
if (ereg('enum.(.*).',$column['Type'],$match))
$field->values = explode(',',$match[1]);
if (ereg('set.(.*).',$column['Type'],$match))
$field->values = explode(',',$match[1]);
if(!$field->values) $field->values = array();
$field->flags = $flags;
$field->len = mysql_field_len($fields, $i);
$result_fields[$field->name] = $field;
$result_fields[$i] = $field;
}
mysql_free_result($columns);
}
mysql_free_result($fields);
return $result_fields;
}
return false;
}
?>
hope someone else finds this useful.
krang at krang dot org dot uk
10-Mar-2002 06:12
The field type returns what PHP classifies the data found in the field, not how it is stored in the database; use the following example to retrieve the MySQL information about the field....
<?php
$USERNAME = '';
$PASSWORD = '';
$DATABASE = '';
$TABLE_NAME = '';
mysql_connect('localhost', $USERNAME, $PASSWORD)
or die ("Could not connect");
$result = mysql_query("SHOW FIELDS FROM $DATABASE.$TABLE_NAME");
$i = 0;
while ($row = mysql_fetch_array($result)) {
echo $row['Field'] . ' ' . $row['Type'];
}
?>