无法使用php从表单将数据插入MYSQL

Question

I want to insert data into MYSQL from HTML form using PHP .When i enter a valid string in the form and submit it redirect as per code to main.php btw the entered string is not inserted into MYSQL table.

Here is my code below

HTML

---

<form class="form" action="" method="post" >
    <input type="text" placeholder="User Id" id="userid" name="userid" title="Enter your Roll number">
    <button onclick="validate()" type="submit" id="login-button" name="formSubmit" value="submit">Login</button>

</form>

Here is the form validation.

JS

---

function validate()
{
    var id=document.getElementById('userid').value;
    if(id=="")
    {
        document.getElementById('msg').innerHTML = "Please enter User Id";
        setTimeout(function(){
        window.location.replace('index.php');
        }, 2000);
    }
    else
    {
        if(id.length=="10")
        {
            document.getElementById('msg').innerHTML = "Login Success";
            setTimeout(function(){
            window.location.replace('main.php');
            }, 2000);
        }
        else
        {   
            document.getElementById('msg').innerHTML = "Please enter valid User Id";
            setTimeout(function(){
            window.location.replace('index.php');
            }, 2000);
        }
    }
}

PHP

---

mysql_connect("localhost", "root", "password") or die(mysql_error());
mysql_select_db("gcet_elib") or die(mysql_error());

if(isset($_POST['formSubmit']))
{

    $userid = $_POST['userid'];

    $query = "INSERT INTO users ( uid ) VALUES ('$userid')";

    $result = mysql_query($query);

    if($result){
        //$msg = "User Created Successfully.";

        echo '<script language="javascript">';
        echo 'alert("Login Successfull")';
        echo '</script>';

    }

else
{
    echo '<script language="javascript">';
    echo 'alert("Cant submit this form")';
    echo '</script>';
}

}

---

---

So please help me to find out the mistake in the code.

Answer 1

When I run this code it alerts like this "Cant submit this form" .

it might be because your form requirements are not met which is to be met as defined in the validate() fucntion. check your javascript validate() function. It might be wrong. So post it as edit, or may be you are not passing the required information to the input fields which is required for validate() to be true.

mysql or php is not the problem right now as your form is not even submitted.

your script might be wrong check this see the comments i have put and give a thinking.

function validate()
        {
            var id=document.getElementById('userid').value;
            //if id is null this will rise
            if(id=="")
            {
                document.getElementById('msg').innerHTML = "Please enter User Id";
                setTimeout(function(){
                window.location.replace('index.php');
                }, 2000);
            }
            //if the id is not null this means a string is passed
            else
            {
                //if the id is exactly 10 characters long
                if(id.length=="10")
                {
                    document.getElementById('msg').innerHTML = "Login Success";
                    setTimeout(function(){
                    window.location.replace('main.php');
                    }, 2000);
                }
                //if the id is not null and character length is not equal to 10
                else
                {   
                    document.getElementById('msg').innerHTML = "Please enter valid User Id";
                    setTimeout(function(){
                    window.location.replace('index.php');
                    }, 2000);
                }
            }
        }

In this case if the id is not null or null it will redirect window.location.replace('index.php'); to index.php all the time which is btw meaning even if a string is passed to it or not it will refresh. So correct these conditional statements as you prefer to make it work

Answer 2

If you are seeing that error on load, its normal, because you didn't set a $_POST['formSubmit'] so that if loop will redirect to else and error will be shown.

On loading page, you don't have a post variable set, but the php part will execute and it will find isset($_POST['formSubmit']) as false , and it will go else statement.

Make the following changes.

1. In JS, do all the validations and let JS submit the form.
2. Make complete php code inside if(isset($_POST['formSubmit']), so that php code will execute only after the submit done.

Answer 3

Replace your html with following:

 <form class="form" action="main.php" method="post"> <input type="text" placeholder="User Id" id="userid" name="userid" title="Enter your Roll number"> <button onclick="return validate()" type="submit" id="login-button" name="formSubmit" value="submit">Login</button> </form> 

Replace you javascript with following:

 function validate() { var id = document.getElementById('userid').value; if (id == "") { document.getElementById('msg').innerHTML = "Please enter User Id"; return false; } else { if (id.length == "10") { document.getElementById('msg').innerHTML = "Login Success"; return true; } else { document.getElementById('msg').innerHTML = "Please enter valid User Id"; return false; } } } 

Answer 4

Change your php code a bit like below :

mysql_connect("localhost", "root", "root") or die(mysql_error());
mysql_select_db("stackov") or die(mysql_error());

if(isset($_POST['formSubmit']))
      {

        $userid = $_POST['userid'];

        $query = "INSERT INTO users ( id ) VALUES ('$userid')";

        $result = mysql_query($query);

        if($result){
            //$msg = "User Created Successfully.";

            echo '<script language="javascript">';
            echo 'alert("Login Successfull")';
            echo '</script>';

        }
        else{
          echo '<script language="javascript">';
            echo 'alert("Cant submit this form")';
            echo '</script>';
      }
      }

I have just changed the postion of else block so the message cant submit form will not pop up.

Answer 5

if you want no error when page loading, change PHP file as:

<?php
  mysql_connect("localhost", "root", "root") or die(mysql_error());
  mysql_select_db("stackov") or die(mysql_error());

  if(isset($_POST['formSubmit']))
  {

    $userid = $_POST['userid'];

    $query = "INSERT INTO users ( uid ) VALUES ('$userid')";

    $result = mysql_query($query);

    if($result){
        //$msg = "User Created Successfully.";

        echo '<script language="javascript">';
        echo 'alert("Login Successfull")';
        echo '</script>';

    }
    else{
        echo '<script language="javascript">';
        echo 'alert("Cant submit this form")';
        echo '</script>';
    }
  }
?>

Move else statement on check isset($_POST)

Answer 6

You are just redirecting and changing window location . you need to submit form . you need to provide action as action="main.php" and in validation if you field is not empty or correct according to your validation just use this $( "#formid" ).submit(); jquery function.You form will be submitted and and you will be able to access post values in main.php