Sorry...
kleiner Nachtrag, Scriptfehler! So siehts tatsaechlich aus:
-SCHNIPP---8<------------------------------------------
$getindex1 = mysql_query("SELECT comment,username FROM comments ORDER BY ID");
while($row1 = mysql_fetch_array($getindex1)) {
$source1 = "comments";
$text1 = $row1['comment'];
$username1 = $row1['username'];
$writeindex1 = "INSERT INTO search_index (source,sample,username) VALUES ('$source1','$text1','$username1')";
mysql_query($writeindex1);
}
-SCHNAPP---8<------------------------------------------