CODEWITHSUNDEEP
phpmysqldatabasemysqliprepared-statement
Starfish
Starfish

Reputation: 3574

Check if a value exists before deleting with prepared statement

I'd like to get notified when a movie does not exists. This represents a script to delete movies from the database. This is a part of what I have now:

$title = $_POST["title"];
$delMovie = mysqli_prepare($link, "DELETE FROM movie WHERE title=?");
mysqli_stmt_bind_param($delMovie, "s", $title);
if (mysqli_stmt_execute($delMovie)) {
    echo("Movie \"" . $title . "\" successfully deleted: ");
    echo(mysqli_stmt_affected_rows($delMovie) . " rows affected");
} else {
    echo("Error (" . mysqli_stmt_errno($delMovie) . "): ");
    echo(mysqli_stmt_error($delMovie));
}
mysqli_stmt_free_result($delMovie);
mysqli_stmt_close($delMovie);
mysqli_close($link);

When the movie does not exists, it still returns:

Film "Movie1" successfully deleted: 0 rows affected

As you can see, it doesn't exist, but still returns "Successfully". How can I change this to show:

Error: Movie does not exists in database

Upvotes: 0

Views: 623

Answers (1)

airtech
airtech

Reputation: 496

How about the following: 

if (mysqli_stmt_affected_rows($delMovie) == 0) then
  echo "Error: Movie does not exists in database";

Just because mysql returns 0, doesn't mean you have to show the result as if it's more than one.

=============================================

You're only other option would be to 

1) Do a select statement to check for existence
2) If not exists
   a) Show error
   b) Delete
       - If error deleting, show error
       - Else show success

or 

1) Delete
    - If 0 rows affected or error, Show error message
    - Else show success

I think a variation on the second path makes for cleaner code.

Upvotes: 2

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