MySQL in a Nutshell, 2nd Edition

Name

mysql_data_seek()

Synopsis

bool mysql_data_seek(connection, row)

Use this function in conjunction with the mysql_fetch_row() function to change the current row being fetched to the one specified in the second argument. The connection identifier is given as the first argument. The function returns true if it’s successful; false if it’s unsuccessful. Here is an example:

...
$sql_stmnt = "SELECT wrid, clientid, description
              FROM workreq";
$results = mysql_query($sql_stmnt);
$count = mysql_num_rows($results);
if ($count > 6) mysql_data_seek($results, $count - 6);
$row = mysql_fetch_row($results);
while($row = mysql_fetch_object($results)) {
  print "WR-" . $row->wrid . " Client-" . $row->clientid .
         " - " . $row->description .  "\n";
}
...

In this script excerpt, the SQL statement is selecting the work request identification numbers for all rows in the table. The results set is stored in $results. Using the mysql_num_rows() function, the number of rows is determined and placed in the $count variable. To be able to display only the last five work requests, the script calls mysql_data_seek(). The results set is given as the first argument. In order to get the first row of a results set, the offset would be set to 0—so if a results set contains only one row, the row count of 1 minus 1 would need to be given as the second argument of mysql_data_seek(). For the example here, to get the last five records of the results set, the number of rows is reduced by six to move the pointer to the row before ...