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int mysql_num_fields ( resource result )

mysql_num_fields() возвращает количество полей результата запрооса result.

См. также mysql_select_db(), mysql_query(), mysql_fetch_field() и mysql_num_rows().

Для совместимости, как алиас, доступна устаревшая функция mysql_numfields(). Однако, использовать её крайне не рекомендуется.

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mysql_num_fields

php at jezusisheer dot nl
30-Mar-2007 12:10


Note that, if you want to get the amount of columns of a table and you're using the "SHOW COLUMNS FROM $table" query, you will have to use mysql_num_rows() instead of mysql_num_fields() on the result. This becomes logical when thinking about it, because the SHOW COLUMNS query returns a result with six columns (Field, Type, Null, Key, Default and Extra) and with a single row for every column found. If you'd count the number of fields, you'd always get 6. If you count the number of rows, you'll get the amount of columns found.

tharkey at tharkey dot net
19-Jun-2003 11:26


You can use it without a requete, just to list the fields :



$liste_champs = mysql_list_fields ( $Base, $Table, $connexion);



for ($i=0; $i < mysql_num_fields ($l_champs); $i++) {

                        echo ( mysql_field_name ($l_champs, $i) );

                        echo (' / ');

                        }

apass AT passmoore DOT com
01-Oct-2002 03:52


Adding to the last comment: you can dynamically loop through any number of  columns AND rows like so-



$query="your SQL";

$result=mysql_query($query) or die("Query ($query) sucks!");

$fields=mysql_num_fields($result);



echo "<table>\n<tr>";

for ($i=0; $i < mysql_num_fields($result); $i++) //Table Header

{ print "<th>".mysql_field_name($result, $i)."</th>"; }

echo "</tr>\n";

while ($row = mysql_fetch_row($result)) { //Table body

echo "<tr>";

    for ($f=0; $f < $fields; $f++) {

    echo "<td>$row[$f]</td>"; }

echo "</tr>\n";}

echo "</table><p>";



This has been tested.

matt at iwdt dot net
23-Sep-2001 06:09


here's one way to print out a row of <th> tags from a table

NOTE: i didn't test this



$result = mysql_query("select * from table");



for ($i = 0; $i < mysql_num_fields($result); $i++) {

    print "<th>".mysql_field_name($result, $i)."</th>\n";

}



post a comment if there's an error

bwark at stanford dot edu
24-Dec-2000 02:56


If you just want the number of fields in a table, you can do something like this:

--

$db_id = mysql_connet();

$result = mysql_query("DESCRIBE [tableName], $db_id);



$numFields = mysql_num_rows($result);

--

Because "DESCRIBE" returns one row for each field in the table (at least in MySQL), this will work.

dubious at 2xtreme dot net
13-Sep-2000 02:35


Examples?  How about this for a highly contrived but hopefully understandable example:

------------------------

<?php

function DoAQuery($Query)

   {

   $Result=mysql_db_query($Query);

   $NumberOfFields=mysql_num_fields($Result);

   print("There are $NumberOfFields Columns in the result<br>");

   }    

    $ConnectionResource=mysql_connect("localhost","User","Password");

$Query="SELECT This, That, TheOther from Some_Table ORDER BY This";



DoAQuery($Query);

?>

-------------------------

Presuming I did that right, the entire output of this snippet should be "There are 3 Columns in the result" (assuming you actually have a mysql database with those fields, etc.)  Presumably, in the Real World, you'd be using mysql_num_fields for formatting and such.



Hey, I SAID it was highly contrived, didn't I?

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