如何在MySQL查询结果中找到特定的行？

Question

So I do this to retrieve my entire table:

$result = mysql_query( 'SELECT * FROM mytable' );

Then, in another part of my PHP-page, I do another query (for a specific row):

$result2 = mysql_query( 'SELECT * FROM mytable WHERE id = ' . $id );
$row = mysql_fetch_array( $result2 );

So, I'm performing two querys. However, I don't really have to do that, do I? I mean, the row that I'm retrieving in my second query already is present in $result (the result of my first query), since it contains my entire table.

Therefore, instead of doing the second query, I would like to extract the desired row from $result directly (while keeping $result itself in tact).

How would I do that?

---

OK, so this is how I've implemented it:

function getRowById ( $result, $id )
{
    while ( $row = mysql_fetch_array( $result ) ) {
        if ( $row['id'] == $id ) {
            mysql_data_seek( $result, 0 );
            return $row;
        }
    }
}

Answer 1

You can loop through the result set to find the row, and then reset the internal pointer back to the first row:

while($row = mysql_fetch_array( $result))
{
  if($row['id'] == $id)
  {
    //row found, do processing ...
    //reset pointer and break from loop
    if(!mysql_data_seek($result, 0))
      //handle error
    break;
  }
}