PHP更新表单，仅当使用PDO在该特定字段中存在输入时才更新数据库信息

Question

I am currently working on a form that uses PHP and SQL to update information in a database. It is functioning properly and updating the information but the issue is... is that it updates everything, including fields that I didn't even put any input in which means it will only update a particular row in the database and leave the others blanks... I need it to just change information from a field with an actual input and leave it if there is no input.

Here is the PHP and SQL code:

try {

$deleteRecId = $_GET['id'];
$update_event_name = $_POST['updateName'];
$update_event_location = $_POST['updateLocation'];
$update_event_date = $_POST['updateDate'];

include 'connect.php';

if(isset($_POST["submit"])) {

// new data
$sql = "UPDATE events SET event_name='$update_event_name', 
event_location='$update_event_location', event_date='$update_event_date' 
WHERE event_id=$deleteRecId";

// Prepare statement
$stmt = $conn->prepare($sql);

// execute the query
$stmt->execute();

// echo a message to say the UPDATE succeeded
echo $stmt->rowCount() . " records UPDATED successfully";
}
}

catch(PDOException $e)
{
echo $sql . "<br>" . $e->getMessage();
}

and here if the form:

<form class="update-form" action="<?php echo $_PHP_SELF ?>" method="post">

  <p id="input-headers">Event Name</p>

  <p id="update-input-field-wrapper">
    <input type="text" name="updateName" value="">
  </p>

  <p id="input-headers">Event Location</p>

  <p id="update-input-field-wrapper">
    <input type="text" name="updateLocation" value="">
  </p>

  <p id="input-headers">Event Date</p>

  <p id="update-input-field-wrapper">
    <input type="text" name="updateDate" value="" placeholder="01/01/2000">
  </p>

  <input type="submit" name="submit" value="Submit" id="updateBtn">

</form>

So to sum up I need this application to only update information of a field with an actual input and if the form field has no input I need that database info to remain the same. I appreciate any help with this as I am pretty new to these concepts... thanks!

Answer 1

Using your current code structure, you can do this.

1. Use SQL to select * from event ID. Populate your update_event_xxx with the parameters.

2. If $_POST[xx] is blank, ignore. Else, update_event_xx = $_POST[xx]