PHP中MySql函数收集

<?php
 
$conn  =  mysql_connect ( "localhost" ,  "mysql_user" ,  "mysql_password" );
 
if (! $conn ) {
    echo  "Unable to connect to DB: "  .  mysql_error ();
    exit;
}
  
if (! mysql_select_db ( "mydbname" )) { 
    echo  "Unable to select mydbname: "  .  mysql_error ();
    exit;
}
 
$sql  =  "SELECT id as userid, fullname, userstatus 
        FROM   sometable
        WHERE  userstatus = 1" ;
 
$result  =  mysql_query ( $sql );
 
if (! $result ) {
    echo  "Could not successfully run query ( $sql ) from DB: "  .  mysql_error ();
    exit;
}
 
if ( mysql_num_rows ( $result ) ==  0 ) {
    echo  "No rows found, nothing to print so am exiting" ;
    exit;
}
 
// While a row of data exists, put that row in $row as an associative array
// Note: If you‘re expecting just one row, no need to use a loop
// Note: If you put extract($row); inside the following loop, you‘ll
//       then create $userid, $fullname, and $userstatus
 while ( $row  =  mysql_fetch_assoc ( $result )) {
    echo  $row [ "userid" ];
    echo  $row [ "fullname" ];
    echo  $row [ "userstatus" ];
}
 
mysql_free_result ( $result );
 
?>