检查选定行中列的所有值

Question

I would like to find out if all the column of the row selected has the equal value. And if all have the same values I would like to perform some action.

id (tableA)   id2 (reference tableB) status
-------------------------------------------
     1               2               On 
     2               2               Off
     3               3               On
     4               3               On

if id2=3 have the same value of status { // perform action here }. How can I check the values of id=3 then perform some action here? I'm using mysql and php.

I don't know if I'm doing it right:

$change = mysql_query("SELECT status from  tableA where status =   'On' and id=3 ");
if ($change == 'On')// if all the columns

{ mysql_query("  UPDATE tableB 
         SET status2 = 'On Going' where id2 =3")or die(mysql_error());
}

Result should be updated in tableB:

id    status2
---------------
3     On Going

Answer 1

$change = mysql_query("SELECT `stat` from  `order_details` 
          where `stat` =  'Cancelled'");
$res=mysql_fetch_array($change);

remember it will fetch only last value from database if you want all the records you must use while loop

    if ($res == "Cancelled")
{


         mysql_query("UPDATE `order1` 
                 SET `status` = 'Cancelled' where `order_id` ='".$order_id."'")or die(mysql_error());
    }

try this...

Answer 2

• You might want to use mysql_num_rows() function of PHP to achieve your goal.
• Are you sure that status column name is different from the stat column name? And they are not the same column?
• Use a tick ( ' ) to parametize the variable in your query.
• At least use mysql_real_escape_string() function.
• You should practice mysqli_* prepared statement rather than the deprecated mysql_* to prevent SQL injections .

Your revised code:

$change = mysql_query("SELECT stat FROM order_details WHERE stat = 'Cancelled'");
if (mysql_num_rows($change) == 1){ /* IF THE QUERY FOUND 1 RESULT */
  mysql_query("UPDATE order1 SET status = 'Cancelled' WHERE order_id = '$order_id'") or die(mysql_error());
}

If you'll be doing it in prepared statement:

if($stmt = $YourConnectionDB->prepare("SELECT stat FROM order_details WHERE stat = 'Cancelled'")){

  $stmt->execute();
  $stmt->store_result();
  $numberofrows = $stmt->store_result();

  if($numberofrows == 1){
    if($stmt2 = $YourConnectionDB->prepare("UPDATE order1 SET status = 'Cancelled' WHERE order_id = ?")){
      $stmt2->bind_param("i",$order_id);
      $stmt2->execute();
      $stmt2->close();
    } /* END OF SECOND PREPARED STATEMENT */
  } /* END OF CHECKING NUMBER OF ROWS */

  $stmt->close();
} /* END OF PREPARED STATEMENT */