PHP: mysql_data_seek

Description

bool mysql_data_seek ( resource result, int row_number )

mysql_data_seek() moves the internal row pointer of the MySQL result associated with the specified result identifier to point to the specified row number. The next call to mysql_fetch_row() would return that row.

row_number starts at 0. The row_number should be a value in the range from 0 to mysql_num_rows() - 1. However if the result set is empty (mysql_num_rows() == 0), a seek to 0 will fail with a E_WARNING and mysql_data_seek() will return FALSE.

Examples

Example 1. mysql_data_seek() example

<?php $link = mysql_connect('localhost', 'mysql_user', 'mysql_password'); if (!$link) { die('Could not connect: ' . mysql_error()); } $db_selected = mysql_select_db('sample_db'); if (!$db_selected) { die('Could not select database: ' . mysql_error()); } $query = 'SELECT last_name, first_name FROM friends'; $result = mysql_query($query); if (!$result) { die('Query failed: ' . mysql_error()); } /* fetch rows in reverse order */ for ($i = mysql_num_rows($result) - 1; $i >= 0; $i--) { if (!mysql_data_seek($result, $i)) { echo "Cannot seek to row $i: " . mysql_error() . "\n"; continue; } if (!($row = mysql_fetch_assoc($result))) { continue; } echo $row['last_name'] . ' ' . $row['first_name'] . "<br />\n"; } mysql_free_result($result); ?>

User Contributed Notes
mysql_data_seek

arturo_b at hotmail dot com
20-Apr-2005 10:53


hello, this script would be easy to understand for those that are novice in php whose want to understand about this function:



the table "user" have 2 columns "id" and "name".

"user" content:

position 0: "id"=195342481 "name"='Arthur'

position 1: "id"=179154675 "name"='John'

>>position 2<<: "id"=157761949 "name"='April' >>third row<<

position 3: "id"=124492684 "name"='Tammy'

position 4: "id"=191346457 "name"='Mike'



<?php

  mysql_connect("localhost", "root")

  mysql_select_db("test");

  $sql = mysql_query("select * from user");

  mysql_data_seek($sql, 2);

  echo "<table border=1>";

  while ($row = mysql_fetch_row($sql)){

    echo "<tr><td>$row[0]</td><td>$row[1]</td></tr>";

  }

  echo "</tabla>";

?>



explanation:

mysql_data_seek move internal result pointer to the third row of table user. Thus mysql_fetch_row will begin by april�s row.

b.steinbrink at g m x dot de
09-Dec-2004 01:09


to kennethnash1134 at yahoo dot com



your loop can be done like this as well and i guess this is faster:



$r=mysql_query("select user,id,ip from accounts limit 10");



unset($users); // Just to be sure

while($users[] = mysql_fetch_row);

array_pop($users); // Drop the last entry which is FALSE

cpl at menwithpignoses dot com
22-Nov-2004 12:28


Everything written down here is wrong. Please re-do much much better.

kennethnash1134 at yahoo dot com
26-Mar-2004 02:12


/*here is a nice function for converting a mysql result row set into a 2d array, a time saver if need small data from several rows, saves you from having to do Alot of queries... would be nice to have this built into PHP future versions :) */



// simple example query

$r=mysql_query("select user,id,ip from accounts limit 10");



//starts the for loop, using mysql_num_rows() to count total

//amount of rows returned by $r

for($i=0; $i<mysql_num_rows($r); $i++){

             //advances the row in the mysql resource $r

    mysql_data_seek($r,$i);

             //assigns the array keys, $users[row][field]

    $users[$i]=mysql_fetch_row($r);

}



//simple, hope someone can use it :)

// -Kenneth Nash

justus dot brugman at 12move dot nl
14-Oct-2000 04:59


So you can use it as the equivalent of the reset() call for an array.


eg.


while ($row = mysql_fetch_object($result_01)) 


{


// code goes here


  while ($row = mysql_fetch_object($result_02)) 


  {


   // code goes here.


  }


  mysql_data_seek($result_02,0)


}





Still hoping that there is going to be a better way, like mysql_reset($result).

mysql_data_seek

Description

Parameters

Return Values

Examples

Notes

See Also