mysql_list_fields

(PHP 4, PHP 5, PECL mysql:1.0)

mysql_list_fields — List MySQL table fields

Description

resource mysql_list_fields ( string $database_name, string $table_name [, resource $link_identifier] )

Retrieves information about the given table name.

This function is deprecated. It is preferable to use mysql_query() to issue a SQL SHOW COLUMNS FROM table [LIKE 'name'] statement instead.

Parameters

database_name: The name of the database that's being queried.
table_name: The name of the table that's being queried.
link_identifier: The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect() is assumed. If no such link is found, it will try to create one as if mysql_connect() was called with no arguments. If by chance no connection is found or established, an E_WARNING level warning is generated.

Return Values

A result pointer resource on success, or FALSE on failure.

The returned result can be used with mysql_field_flags(), mysql_field_len(), mysql_field_name() and mysql_field_type().

Examples

Example 1406. Alternate to deprecated 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);

    }

}

?>

The above example will output something similar to:


Array
(
    [Field] => id
    [Type] => int(7)
    [Null] =>  
    [Key] => PRI
    [Default] =>
    [Extra] => auto_increment
)
Array
(
    [Field] => email
    [Type] => varchar(100)
    [Null] =>
    [Key] =>
    [Default] =>
    [Extra] =>
)

Notes

Note: For downward compatibility, the following deprecated alias may be used: mysql_listfields()


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 09:40


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 02:55


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.

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Last updated: Fri, 01 Jun 2007