With php 3.12 the following lines worked very well:

$result3 = mysql ( "schul_db" , 
  "SELECT spf.TextKey " .
  "FROM Schulst_SprFolge=st_spf,Key_Sprachenfolge=spf " .
  "WHERE  (st_spf.StelleID='$st_id') AND (st_spf.CodeKey=spf.CodeKey)" );
         
      $num3 = mysql_numrows ( $result3 );
      $i3 = 0;
      WHILE ( $i3 < $num3 )
      {
        $sprachenfolge    = mysql_result ( $result3 , $i3 , "spf.TextKey" );
        ...
        $i3 ++;
      }

With 4.0 B3 this warning is displayed:

Warning: spf not found in MySQL result index 4 in /home/www/doc/schule/schul-db/index.php3 on line 192

If I remove "spf.", everything is fine:

$sprachenfolge    = mysql_result ( $result3 , $i3 , "TextKey" );

On the other hand, the following lines - with the same logical structure as above - were executed without any error:

$result4 = mysql ( "schul_db" , 
  "SELECT * FROM Schulst_Vorausse=st_vor, Key_Voraussetzung=vor " .
  "WHERE  (st_vor.StelleID='$st_id') AND (st_vor.CodeKey=vor.CodeKey)" );
 $num4 = mysql_numrows ( $result4 );
 $i4 = 0;
 $voraus = "";
 WHILE ( $i4 < $num4 )
 {
   $vor = mysql_result ( $result4 , $i4 , "vor.TextKey" );
    ..
   $i4 ++;
 }