mysql_list_dbs
Every my html table output begins with heading row containing the field names. For that purpose I accepted the short combination of MySQL function, giving me a result similar to the mysql_fetch_array() for the row of values. The following example shows the basic idea. It should be adapted for the specific use:
<?php
//...
$field_names = array_keys( mysql_fetch_array( mysql_query( $query, $link), MYSQL_ASSOC));
//...
?>
The advantage of this is, that it gives the names of the result, neither the field names of the whole table.
Please read the discussion about duplicate field names in SQL result carefully. The use, as shown in the example above, increments the pointer, hence some regular function, which does not, could be more useful :-)
Jan
mysql_list_fields
(PHP 4, PHP 5, PECL mysql:1.0)
mysql_list_fields — Lista los campos del resultado de MySQL
Descripción
int mysql_list_fields
( cadena $base_de_datos
, cadena $tabla
[, int $dentificador_de_enlace
] )
Note: La función mysql_list_fields() es onsoleta. Es preferible usar mysql_query() para ejecutar una sentencia SQL SHOW COLUMNS FROM table [LIKE 'name'].
mysql_list_fields() lista información sobre la tabla. Los argumentos son la base de datos y el nombre de la tabla. Se devuelve un puntero que puede ser usado por las funciones mysql_field_flags(), mysql_field_len(), mysql_field_name(), y mysql_field_type().
Un identificador de resultado es un entero positivo. La función devuelve -1 si se produce un error. Una cadena de caracteres describiendo el error será introducida en $phperrmsg, y a menos que la función sea llamada como @mysql() el literal del error también será desplegado.
Example #1 Ejemplo alternativo a mysql_list_fields
<?php
$result = mysql_query("SHOW COLUMNS FROM sometable");
if (!$result) {
echo 'Could not run query: ' . mysql_error();
exit;
}
if (mysql_num_rows($result) > 0) {
while ($row = mysql_fetch_assoc($result)) {
print_r($row);
}
?>
El ejemplo anterior producirá una salida similar a:
Array ( [Field] => id [Type] => int(7) [Null] => [Key] => PRI [Default] => [Extra] => auto_increment ) Array ( [Field] => email [Type] => varchar(100) [Null] => [Key] => [Default] => [Extra] => )
Por razones de compatibilidad puede usarse también mysql_listfields(). Sin embargo esta funció es obsoleta.
Vea también mysql_field_flags(), mysql_info().
add a note
User Contributed Notesmysql_list_fields
perwool at seznam dot cz
29-Oct-2007 11:32
29-Oct-2007 11:32
khashmeshab at yahoo dot co dot uk
12-Sep-2007 11:48
12-Sep-2007 11:48
You can use this SQL command instead of 'SHOW FIELDS FROM tablename;':
'DESC tablename;'
steve at tequilasolutions dot com
12-Sep-2006 03:33
12-Sep-2006 03:33
Note, using mysql_list_fields will change the currently selected database so subsequent mysql_query operations will be on the database in param 1 not the one selected with mysql_select_db
arster
15-Oct-2005 09:05
15-Oct-2005 09:05
# This should also give you an array of column names
$res = mysql_query("SHOW COLUMNS FROM `my_table`");
while ($row = mysql_fetch_array($res)) $col_names[]=$row[0];
harryzhong at hotmail dot com
26-Jul-2005 06:27
26-Jul-2005 06:27
Here is a simple script get names of columns in an array:
//Get names of columns in table
$field_names = array();
$res = mysql_query("SHOW COLUMNS FROM `my_table`");
for($i=0;$i<mysql_num_rows($res);$i++){
array_push($field_names,mysql_result($res, $i));
}
rhyous at yahoo dot com
05-Jun-2005 12:22
05-Jun-2005 12:22
To make an array containing the names of a column from a table, you use the following simple script: (Note: using table1 with three columns)
$qColumnNames = mysql_query("SHOW COLUMNS FROM table1",$db) or die("mysql error");
$numColumns = mysql_num_rows($qColumnNames);
$x = 0;
while ($x < $numColumns)
{
$colname = mysql_fetch_row($qColumnNames);
$col[$colname[0]] = $colname[0];
$x++;
}
print_r($col);
/* it will have the following output
Array (
[firstcolumn] => firstcolumn
[secondcolumn] => secondcolumn
[thirdcolumn] => thirdcolumn
)
*/
Or you can number the columns from zero. This help when using it in conjunction with mysql_fetch_row to get an array. You don't have to remember which number of the array a certain column is.
$qColumnNames = mysql_query("SHOW COLUMNS FROM table1",$db) or die("mysql error");
$numColumns = mysql_num_rows($qColumnNames);
$x = 0;
while ($x < $numColumns)
{
$colname = mysql_fetch_row($qColumnNames);
$col[$colname[0]] = $x;
$x++;
}
print_r($col);
/* it will have the following output
Array (
[firstcolumn] => 0
[secondcolumn] => 1
[thirdcolumn] => 2
)
*/
To use it in conjuction with mysql_fetch_row:
$row = mysql_fetch_row("SELECT * from table1",$db) or die("mysql error");
You can now call $row[col[firstcolumn]]. This becomes useful when you have a lot of columns.
mbevan at marginsoftware dot com
13-Nov-2003 10:40
13-Nov-2003 10:40
If you're willing to use a lot of functions to get a little information about fields in a table, this function is for you. If you just want to get all the information you can find, you can use this:
<?php
// Taken from: http://ca.php.net/manual/en/function.mysql-field-flags.php
// Original by: amir at scrounch dot com
// Returns the name of the fields in the primary key for a table.
// Also keeps the fields in KEY order. Handy.
function getPrimaryKeyOf($table) {
$keys = Array();
$query = sprintf("SHOW KEYS FROM `%s`", $table);
$result = mysql_query($query) or die(mysql_error());
while ($row = mysql_fetch_assoc($result)) {
if ( $row['Key_name'] == 'PRIMARY' )
$keys[$row['Seq_in_index'] - 1] = $row['Column_name'];
}
return $keys;
}
// Returns a bunch of information about a table...
// The name of the auto-increment field, if any, fields in the
// primary key (using the function above), and all information
// about all fields.
function getTableInformationOf($table) {
$information = array(
"auto" => "",
"primary" => array(),
"fields" => array()
);
$information['primary'] = $this->getPrimaryKeyOf($table);
$result = mysql_query("DESC `$table`");
while ( $field = mysql_fetch_assoc($result) ) {
$information['fields'][] = $field;
if ( $field['Extra'] == "auto_increment" )
$information['auto'] = $field['Field'];
}
return $information;
}
?>
dom at brainwaveuk dot com
19-Jul-2002 04:55
19-Jul-2002 04:55
mysql_list_fields() retrieves information about the given table name but you can use something like mysql_fetch_field to retrieve the field names from a result source.