php：编辑和删除[关闭]

I want to make a registration form page which also contains a table where we retrieve the data entered through the form into the database. The table also have edit and delete options so that we can later make any change. I saw an example, how to make such 'edit and delete' table. But I could not understand the code given below:

<?php

    if(isset($_REQUEST['s']))
    { 
        if($_REQUEST['s']=="m")
        {
            echo "Successfully deleted.";
        }
    }

    if(isset($_REQUEST['s']))
    { 
        if($_REQUEST['s']=="e")
        {
            echo "Successfully update.";
        }
    }
?>

Can you explain it's meaning, line by line?

the code below doesn't make much sense. If anything it should be re-written

if(isset($_REQUEST['s']))
{ 
    switch($_REQUEST['s'])
    {
        case "m":
            echo "Success fully deleted.";
            break;
        case "e":
            echo "Success fully update.";
            break;
    }
}

This code checks if "s" has been passed either as $_POST or $_GET variable, if it was s=m then display message, that entity was successfully deleted, if e, it was successfully updated.

In general, try using more verbose names of variables, and avoid $_REQUEST due to security implications

$_REQUEST['s'] ----> This will get the submit button name <input type="submit" name="s" value="m" />

m and e is the value of submit button

<?php
 if(isset($_REQUEST['s'])) // to check if button is pressed or not  
{ if($_REQUEST['s']=="m")  //if m button is clicked
{ 
 //code for delete
echo "Success fully deleted.";
}}
 if(isset($_REQUEST['s']))  
{ if($_REQUEST['s']=="e")  // if e button is clicked
{
  //code for update into db
echo "Success fully update.";
}}
?>

    if(isset($_REQUEST['s'])) { // If a Requst "s" exists eq index.php?s=hello
     if($_REQUEST['s']=="m") {  // Now lets see what value the Request "s" has IF s=="m"
         echo "Success fully deleted."; // Output because s has the Value "m"
     }
    }

Fort better understanding just try this

    if(isset($_REQUEST['s'])) { 
     if($_REQUEST['s']=="m") {  // Now lets see what value the Request "s" has IF s=="m"
         echo "Success fully deleted."; // Output because s has the Value "m"
     } else {
        echo "s is not equal 'm': s has the value ".$_REQUEST['s'];
     }
    } else {
      echo "i need the Request s to do something";
      echo "<pre>Requests i got: ".print_r($_REQUEST,1)."</pre>";
   }

Now try it by:

yourscript.php?s=m

yourscript.php?s=hello

yourscript.php